Vitoria-Gasteiz July 5-7, 2017 - Grupo de … · D Félix Pariente Alonso ... B Noemí De Los...

Vitoria-Gasteiz July 5-7, 2017

#38gerseq

INDEX

Official Programme

Vitoria-Gasteiz Map

Europa Congress Palace Map

Plenary Sessions & Awards

Oral Contributions

ISE Session “Regional Student Meeting” - Master Students

ISE Session “Regional Student Meeting” - PhD Students

Posters

3

7

8

11

19

91

111

123

OFFICIAL PROGRAMME

PROGRAMME

Registration (registration will be available on 4th July from 16:00 to 19:00).

Welcome act.

Plenary Session 1Speaker: Toribio F. Otero.

Chairman: Iluminada Gallardo.

Coffee break. Visit to posters & exhibition area.

Assembly of the Electrochemistry Group from RSEQ.

Cidetec 2016 Awards Ceremony. Lunch.

ISE Session: EC&T Master and Doctoral Programmes Students Presentations.

Coffee break.

Excellence Network: Sensor & Electrochemical Biosensor (ElectroBionet).

Excellence Network: Energy & Environmental Applications to Electrochemical Technology (E3TECH). Tour & Pintxopote experience.

Wednesday 5th July

08:30 - 09:00

09:00 - 09:20

09:20 - 10:05

10:05 - 10:25

10:25 - 12:00

12:00 - 13.00

13:00 - 14:30

14:30 - 17:00

17:00 - 17:15

17:15 - 18:00

18:00 - 18:45

19:00 - 21:00

Registration.

EC&T Master and Doctoral Programmes Commissions Meeting.

Tuesday 4th July

16:00-19:00

16:00-18:00

4

MARIA DE MAEZTU

BARANDIARAN

BARANDIARAN G1, GASTEIZ G2, HECHICERA G3, PORTILLA G4, PRADO G5, SALBURUA G5, SORGINETXE G7*

*G1: group 1, G2: group 2, G3: group 3, G4: group 4, G5: group 5, G6: group 6, G7: group 7.

SALBURUA

5

PROGRAMMEThursday 6th July

Registration.

Plenary Session 2.Speaker: Enric Brillas.

Chairman: Manuel Blázquez.

E Enrique OrtíE Vicente F. MenaE Laura Valero


E Salvador CotillasE Ignacio SanjuanE Inmaculada Moraleda

Lunch.

Plenary Session 3.Speaker: José Manuel Pingarrón.

Chairman: Vicente Montiel.

E Silvia BarbaE Martin Muñoz MoralesE Carlota Ridruejo

Coffee break.

E Andrés Del CastilloE Beatriz Gómez-Monedero

Oral José Gabriel Martínez – II Premio Antonio Aldaz.

Visit to posters & exhibition area.

Official dinner. Andere Restaurant (C/Gorbea, 8. 01008 Vitoria-Gasteiz).

09:00-09:30

09:30-10:15

10:15-10:3510:35-10:5510:55-11:15

11:15-11:45

11:45-12:0512:05-12:2512:25-12:4512:45-13:05

13:05-14:30

14:30-15:15

15:15-15:3515:35-15:5515:55-16:15

16:15-16:35

16:35-16:5516:55-17:15

17:15-17:35

17:35-18:30

21:00-23:30

It is not allowed to take pictures or videos during lectures

F Francisco José SarabiaF Nelly Flores

D Guadalupe Sánchez-ObreroD Elena Pastor

G Nisrine BenzbiriaG Francisco PrietoG Valentín Briega-Martos

D Victor Hugo PascualD Aránzazu HerasD Félix Pariente Alonso

A Bibiana Mª Fernández PérezA Víctor Ruiz-ValdepeñasA Francisco Vicente

B Eva Vargas OrgazB Noemí De Los Santos Alvárez

B Sara GuerreroB Sara Mateo

A Esther Sánchez-TiradoA Verónica SerafínA Miguel Aller

C Florencio SantosC Maider ZarrabeitiaC Naiara Hernández

D Ramón M. Fernández-DomeneD Samuel BeaumontD Paula SebastiánD Johanna Schumacher

C Uxua Jiménez BlascoC Pilar OcónC Antonio J. Fernández Romero

D Siham EchihiD Leticia García CruzD Bianca Lucas-Granados

FRANCISCO DE VITORIA



FRANCISCO DE VITORIA BARANDIARAN PORTILLA GASTEIZ


Chairman Pere Lluis Cabot Álvaro Colina Lide M. Rodríguez Elvira Gómez

Chairman Ignacio Sirés Paloma Yañez Montserrat Casas-Cabanas Elisa Vallés

Chairman José García Antón Joaquín González Ángel Cuesta Josep Galceran

Chairman Francisco Cases Mª Encarnación Lorenzo Pilar Ocón Fco. Javier del Campo

PROGRAMMEFriday 7th July

6

A- Analytical electrochemistryB- BioelectrochemistryC- Electrochemical energy storage & conversionD- Material electrochemistryE- Electrochemical process technology & engineeringF- Molecular electrochemistryG- Fundamental electrochemistry

Registration.

Plenary Session 4Speaker: Anthony K. Burrell.

Chairman: Teófilo Rojo.

D Mª Carmen Arévalo

D Jadra Mosa

D Sergio Castro


B Mª Encarnación Lorenzo

B Hugo Silva

B Rafael Del Caño

B José Luis Olloqui-Sariego

Poster Award Ceremony.

II Premio Antonio Aldaz Award Ceremony.

Closing ceremony.

09:00-09:30

09:30-10:15

10:15-10:35

10:35-10:55

10:55-11:15

11:15-11:45

11:45-12:05

12:05-12:25

12:25-12:45

12:45-13:05

13:05-13:45

F Iluminada Gallardo

F Álvaro Colina

F Rafael Madueño

A Jerónimo Agrisuelas

A Juan V. Perales

A Edelmira Valero

A Mª Isabel González Sánchez

C Cristina Botas

C Mikel Pino

C Teresa Andreu

C Guoxiu Wang

G Joaquín González

G Ángela Molina

G Eduardo Laborda

C Nebil A. Katcho

C Elena Gonzalo

C Begoña Silván

G Ángel Cuesta

G Mercedes Sánchez

G José J. García - Jareño





Chairman José Solla Rafael Andreu Javier Carrasco Enrique Herrero

Chairman Aránzazu Heras Teresa Pineda Eider Goikolea Francisco Prieto

Pow

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ture

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Map1

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5AC GENERAL ÁLAVA HotelFlorida, 7

SILKEN CIUDAD DE VITORIA Hotel Portal de Castilla, 8

CENTRO VITORIA Hotel General Álava, 11 - Pasaje interior

TOMÁS ALFARO FOURNIER University ResidencePaseo Zumaquera, 21

EUROPA CONGRESS PALACEAvda. Gasteiz, 85

ARTIUM Museum Francia, 24

ANDERE Restaurant Gorbea, 8

RENFE - Train Station Dato, 46

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6

Aven

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de G

aste

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Aven

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aste

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Adriano VI

Plaza deLovaina

Sancho El Sabio

Manuel Iradier

Florida

San Prudencio

Dat

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General Alava

Postas

Olaguibel

Francia

Portal de Castilla

Beato Tomas de Zumarraga

Badaya

Fray

Zac

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U N I V E R S I T Y

1

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Gor

bea

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Ramón y Cajal

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7

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Luis Heinz

New Cathedral

7

Manuel Iradier

Paseo de la Zumaquera

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8

U N I V E R S I T Y

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1

2

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34

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9It is not allowed to take pictures or videos during lectures

EUROPA CONGRESS PALACE

MARÍA DE MAEZTU

GREEN

BARANDIARAN

ARMENTIA

PORTILLA


REGISTRATIONS

POSTERS

MIRADOR TECHNICAL OFFICE

11

SALBURUA SORGINETXE

LA HECHICERA GASTEIZ

1

2

3

4 7

85

6 9

1ST FLOOR

2ND FLOOR

LOW LEVEL

PRADO

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15

PLENARY SESSIONS

AWARDS

12

PLENARY 1 09:20-10:05Wednesday 5th July

Replicating biological functions from multistep electrochemical molecular machines: experiments, devices and models.Toribio F. Otero.

Laboratory of Electrochemistry, Intelligent Materials and Devices. Technical University of Cartagena. ETSII. 30203, Cartagena. Spain.

By electrochemical reactions in liquid electrolytes films of conducting polymers, carbon nanotubes, fullerenes and other electronic conductors and electoactive materials exchange counterions, for charge balance, and solvent, for osmotic balance, with the electrolyte. The film becomes a dense gel mimicking, in its simplest expression, the intracellular matrix of functional cells. The reaction injects or extracts n electrons through consecutive steps of one electron from every chain.

Every electron transfer changes the double bond’s distribution along the chain originating reversible conformational movements: every chain becomes a multistep molecular machine, replicating similar motors originating biological functions in living cells. The cooperative actuation of the chains taking part of a film originates or destroys the free volume required to lodge/expel counterions and solvent. The electrochemical reactions drive macroscopic structural transformations: swelling, shrinking, closing, conformational compaction and conformational relaxation.

Material’s composition, molecular motors and reaction-driven structural changes replicate the consecutive events taking place in functional cells originating biological functions [1]. Here we will review how artificial muscles, biosensors, sensing and tactile muscles, proprioceptive devices, smart membranes or artificial synaptic connections, among other devices are being develo-ped. Theoretical models for artificial proprioception and structural chemical kinetics will be presented [2–4]. Those models also can describe biological functions like respiration, allosteric biosensors or enzymatic catalysis, providing some quantitative hypothesis for brain memory.

A new technological world is emerging constituted by electrochemical, soft, wet and reactive, anthropomorphic and zoomor-phic tools and robots having similar texture, functionalities and elegant movements as those from humans beings or animals. A critical mass of scientists, engineers and robot designers with a solid background on the electrochemical synthesis and the electrochemical characterization of both, materials and biomimetic devices, is required for its implementation. Thousands of new companies and a plethora of new job positions will be there involved.

References:T. F. Otero, Conducting Polymers: Bioinspired Intelligent Materials and Devices, RSC, 2015.1. T.F. Otero, J.G. Martinez, Physical and chemical awareness from sensing polymeric artificial muscles. Experiments and modeling, Prog. Polym. Sci. 44 (2015) 62–78.2. T.F. Otero, J.G. Martinez, Structural and biomimetic chemical kinetics: kinetic magnitudes include structural information, Adv. Funct. Mater. 23 (2013) 404–416.3. T.F. Otero, Reactions driving conformational movements (molecular motors) in gels: conformational and structural chemical kinetics, Phys. Chem. Chem. Phys. 19 (2017) 1718–1730. doi:10.1039/C6CP06735B.

13

PLENARY 2 09:30-10:15Thursday 6th July

Avances en el tratamiento de aguas residuales por procesos electroquímicos de oxidación avanzada.Enric Brillas.

Laboratori d’Electroquímica dels Materials i del Medi Ambient, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona.

En esta conferencia se presenta los avances más interesantes de la aplicación de los procesos electroquímicos de oxidación avanzada (PEOAs) a la destrucción de contaminantes orgánicos en aguas residuales sintéticas y reales. Estos métodos e basan en la generación in situ de radicales hidroxilo (OH) fisisorbidos sobre la superficie de ánodos M de alto sobrevoltaje de oxígeno (M(OH)), como sólo ocurre en el caso de la oxidación anódica (OA) según la reacción (1) [1-3]:

M + H2O --> M(OH) + H+ + e (1)

Se han desarrollado otros PEOAs con mayor capacidad oxidativa que la OA porque pueden producir radicales OH en el seno de la disolución mediante la reacción química de Fenton, como el electro-Fenton (EF) y el fotoelectro-Fenton UV (FEF) y solar (FEFS) [1,3]. En estos últimos tratamientos se aprovecha la radiación lumínica para degradar intermedios como complejos de Fe(III) con ácidos carboxílicos finales que se generan en el transcurso del proceso degradativo. Para el proceso FEFS se pondrá énfasis en el uso de plantas de flujo autónomas que pueden operar en lugares remotos gracias al suministro de la energía eléctrica por paneles fotovoltaicos solares [1]. También se hará referencia a los sistemas integrados de sonólisis con AO (SAO) donde se aprovecha la irradiación ultrasónica para la mejora del transporte de masa hacia el ánodo y la formación de radicales OH mediante cavitación a fin de acelerar la destrucción de la materia orgánica [2]. Para todos estos métodos se expondrán ejemplos para mostrar la influencia de las variables experimentales más importantes, como son el ánodo usado (diamante dopado con boro (BDD), Pt, DSA de oxígeno o de cloro), la intensidad de corriente aplicada y los iones presentes en el efluente.

Finalmente, se destacarán algunos procesos combinados de PEOAs basados en la reacción química de Fenton con métodos más convencionales. Se describirá el uso del FEFS combinado con la fotocatálisis heterogénea solar con TiO2 para la remedia-ción de disoluciones sintéticas de ácido salicílico [3] y el tratamiento de aguas residuales textiles mediante electrocoagulación con ánodos de Fe seguida de FEF que permite eliminar más del 90% de la materia orgánica inicial. También se hará referencia al desarrollo del proceso Bio-electro-Fenton (Bio-EF) en el que se degrada un agua residual por EF, seguida de un post-trata-miento biológico, con lo que se consigue una mejora substancial en el rendimiento de mineralización con un menor coste energético.

Referencias:1. S. Garcia-Segura, E. Brillas, Advances in solar photoelectro-Fenton: Decolorization and mineralization of the Direct Yellow 4 diazo dye using an autonomous solar pre-pilot plant, Electrochim. Acta 140 (2014) 384-395.2. F. Souza, C. Sáez, M. Lanza, M.A. Rodrigo, Removal of herbicide 2,4-D using conductive-sono-electrochemical oxidation. Sep. Purif. Technol. 149 (2015) 24-30.3. B. Garza-Campos, E. Brillas, A. Hernández-Ramírez, A. El-Ghenymy, J.L. Guzmán-Mar, E.J. Ruiz-Ruiz, Salicylic acid degradation by advanced oxidation processes. Coupling of solar photoelectro-Fenton and solar heterogeneous photocatalysis, J. Hazard. Mater. 319 (2016) 34-42.

PLENARY 3

14

14:30-15:15Thursday 6th July

Biosensado electroanalítico fiable y no invasivo de biomarcadores de estadios tempranos de cáncer.José M. Pingarrón.

José M. Pingarrón, Susana Campuzano, Rebeca M. Torrente-Rodríguez, Víctor Ruiz-Valdepeñas Montiel, Eva Vargas, Rodrigo Barderas

Departamentos de Química Analítica y Bioquímica y Biología Molecular I, Facultad de CC. Químicas, Universidad Complutense de Madrid, Madrid, 28040, Spain. E-mail: [email protected]

En la actualidad está ampliamente aceptado que el diagnóstico temprano de cáncer es un factor clave en la supervivencia del paciente. El cáncer es responsable de más de 8 millones de muertes al año en todo el mundo y la segunda causa de muerte por detrás de las enfermedades cardiovasculares. Aunque en los últimos años se han logrado avances importantísimos en la prevención y el tratamiento de diferentes tipos de cáncer, la incidencia y prevalencia de esta enfermedad está aumentando en todo el mundo debido al continuo crecimiento y envejecimiento de la población mundial y al mantenimiento o aumento del tabaquismo, la obesidad y los patrones dietéticos de riesgo. Teniendo en cuenta estos antecendentes, la implementación de programas no invasivos de detección masiva de la población de riesgo podría ayudar a reducir drásticamente la mortalidad por cáncer debido a la detección en etapas tempranas, cuando la enfermedad puede ser tratada y curada eficientemente en más del 90% de los pacientes de los ocho tipos de cáncer más comunes. Por lo tanto, la demanda de dispositivos eficientes, sencillos y desechables con tiempos de respuesta cortos, de bajo coste y adecuados para realizar determinaciones descentrali-zadas y fiables de biomarcadores de cáncer ha aumentado considerablemente durante los últimos años.

Dentro de este contexto, en esta charla se presentarán diferentes estrategias basadas en el empleo de bioplataformas electro-químicas novedosas para la el biosensado sensible, selectivo y rápido, de forma individual o multiplexada, de biomarcadores de diferentes niveles moleculares asociados con el diagnóstico temprano de cáncer. En particular, se discutirán las característi-cas más relevantes de nuevas plataformas electroanalíticas para la determinación de miRNAs [1-3] y autoanticuerpos [4] frente a antígenos asociados a tumores (TAA). Las metodologías desarrolladas, basadas en el uso y acoplamiento apropiado de nuevos biorreceptores, micropartículas magnéticas convenientemente funcionalizadas, atractivos formatos de bioensayo y transductores desechables electroquímicos, permiten la determinación fiable de los analitos objetivo a niveles clínicamente relevantes en muestras biológicas de elevada complejidad: células cancerígenas, tejidos humanos (frescos y parafinados) y suero de pacientes en seguimiento por alto riesgo o ya diagnosticados con cáncer.

Estas plataformas para determinación individual o múltiple y de fácil manejo proporcionan resultados en concordancia con los de metodologías convencionales pero en menos tiempo y con menor coste, características que las hacen especialmente atractivas para su implementación en dispositivos fáciles de usar y asequibles para realizar determinaciones de rutina que faciliten el diagnóstico predictivo, el seguimiento terapéutico y el pronóstico de los pacientes, con los beneficios indiscutibles que esto supone para los pacientes y el sistema sanitario. Además, las metodologías desarrolladas pueden extenderse fácilmente a la determinación de otros biomarcadores de relevancia en cáncer u otras enfermedades graves.

References:1. R.M. Torrente-Rodríguez et al. ACS Sensors 2016, 1, 896. 2. R.M. Torrente-Rodríguez et al. Biosens. Bioelectron. 2016, 86, 516. 3. R.M. Torrente-Rodríguez et al. Journal of Biotecnology and Biomedical Engineering 2016, 3, 1064.4. M. Garranzo-Asensio et al. Anal. Chem. 2016, 88, 12339.

PLENARY 4

Approaches to Multivalent Battery Chemistries. Anthony K. Burrell.

15

09:30-10:15Friday 7th July

National Renewable Energy Laboratory (NREL), USA.

The development of multivalent (e.g., Mg2+, Ca2+ and Zn2+) batteries is a potential candidate for the next generation of high energy density electrochemical storages systems. The theoretical volumetric capacity a metal anode coupled with the lack of dendrite formation at a multivalent metal anode provide are an attractive opportunity in energy storage, beyond that of conventional lithium ion. However, the development of multivalent cathodes and electrolytes represent a significant challenge. For example, with Ca metal cells there is no known electrolyte compatible with both the reversible chemistry at a metal anode and a functional cathode. In the Mg systems only a few functional electrolytes are known and a limited range of cathodes have been identified. Zinc cells suffer from lower voltages and lead to lower energy density cells. In this presentation the resent work in the development of functional multivalent cell chemistries, that overcome the limitations of multivalent cells, will be discussed along with recent advances in high energy cathodes for multivalent systems.

CIDETEC 2016 Award for "Scientific Research" 12:00-13:00Wednesday 5th July

Hybrid electrode materials for hybrid energy storage. Pedro Gómez-Romero.

Catalan Institute of Nanoscience and Nanotechnology (ICN2), The Barcelona Institute of Science and Technology (CSIC-BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain.

Electrochemical energy storage is increasingly recognized as a key technology to enable our ongoing transition to a sustainable energy model based on renewable primary sources. Batteries and supercapacitors are two of the key contenders as secondary sources but each of them has their own drawbacks. High-power-density supercapacitors (SCs) are handicapped by low energy densities whereas Li-ion batteries (LIBs), feature the best energy densities but lag behind in power. These opposite drawbacks hamper the applications of SCs and LIBs when both high energy and high power densities are essential. Thus, the race is on to develop new energy storage materials which could deliver high energy at high rates. On the other hand, the complementa-rity of supercapacitors and batteries allows for a positive view of the question by considering the development of hybrid devices, electrodes or materials which could combine the faradaic processes of batteries with the capacitive mechanism of supercapacitors in a synergic combination [1]. Hybrid electroactive materials offer opportunities for synergy and improved properties [2] and those formed by electroactive and conducting materials are of particular interest for energy storage applica-tions (Figure 1).[1, 2]

We have developed a whole line of work dealing with hybrid electroactive (oxides, phosphates, polioxometalates) and conduc-tive materials (conducting polymers or carbons) for energy storage applications (Figure 1).[3-9] The general objective of this research line has been the design and exploitation of electrochemical synergies within the framework of hybrid electrode materials, a research which has deserved the XIII CIDETEC award of research in electrochemistry and which will be described and discussed in this conference.

References:1. D.P. Dubal, V. Ruiz, O. Ayyad and P. Gomez-Romero Chem.Soc.Rev. 2015 44(7):1777-902. P. Gomez-Romero et al. J.Solid State Electrochem. 2010 14(11), 19393. V. Ruiz, J. Suárez-Guevara, P. Gomez-Romero Electrochem. Communications 2012, 24, 35.4. J. Suarez-Guevara, V. Ruiz and P. Gomez-Romero J.Mat.Chem.A, 2014, 2, 1014.5. J. Suárez-Guevara, V. Ruiz, P. Gomez-Romero J. Mater. Chem. A, 2014, 2 (4), 1014 – 10216. DP Dubal, et al. Journal of Materials Chemistry A 2015, 3(46), 23483-234927. Deepak P. Dubal, Rudolf Holze, Pedro Gomez-Romero. Scientific Reports 2014, 4 : 73498. P. Gómez-Romero, D.P. Dubal, D. Gómez ES1641 1064_14052015 20-5-2015WO 2016/185071 A1 Licenciada a la empresa Earthdas 1 Jun 20169. Deepak P. Dubal and Pedro Gomez-Romero 2D-Materials 2016, 3, 031004.

16

CIDETEC 2016 Award for "Young Researchers”

17

12:00-13:00Wednesday 5th July

Enhanced Oxygen Electroreduction Activity by Atomic Ensemble and Electronic Effects.María Escudero Escribano.

University of Copenhagen, Department of Chemistry, Universitetsparken 5, 2100 Copenhagen, Denmark.

One of the most important scientific and technological challenges facing humanity is the switch from fossil fuels to clean energy. Polymer electrolyte membrane fuel cells (PEMFCs) are expected to play a key role in a future society based on sustaina-ble energy. However, the high platinum loadings required to compensate for the slow kinetics of the oxygen reduction reaction (ORR) impede the widespread uptake of these technologies. In order to improve the reaction kinetics and reduce the Pt loading at the fuel cell cathode, we need to develop more efficient electrocatalysts. This can be achieved by modification of the geometric structure (atomic ensemble effects [1]) and/or alteration of the electronic properties of the surface atoms (electronic effects [2,3]).

First, I will address atomic ensemble effects in electrocatalysis. We used a self-ordered molecular pattern, cyanide-modified Pt(111), [CN-Pt(111)] to study the ORR [1]. Cyanide groups block all the three-fold hollow sites, effectively blocking the adsorption of spectator anions from the electrolyte, such as sulphate and phosphate. Nonetheless, the holes in this ordered structure are sufficiently large to allow the adsorption of reaction oxygen molecules. As a consequence, CN-Pt(111) presents a 25-fold enhancement over Pt(111) [1].

Secondly, I will focus on electronic effects by alloying Pt. Researchers have intensively studied alloys of Pt with late transition metals for the ORR. However, these alloys typically degrade by dealloying under fuel cell conditions. In contrast, Pt-lanthanide alloys present a very negative alloying energy, which should increase their resistance to degradation. We have studied novel Pt-lanthanide and Pt-alkaline earth electrodes for the oxygen reduction. These materials are amongst the most active Pt-based catalysts ever reported [2,3]. A Pt overlayer with a thickness of few Pt layers is formed onto the bulk alloys by acid leaching. The oxygen reduction activity versus the lattice parameter follows a volcano relation [3]. We use the lanthanide contraction to control strain effects and tailor the activity, stability and reactivity of Pt alloys.

References:1. D. Strmcnik, M. Escudero-Escribano et al., Nature Chem. 2010, 2, 880. 2. M. Escudero-Escribano et al., J. Am. Chem. Soc. 2012, 130, 16476.3. M. Escudero-Escribano* et al., Science 2016, 352, 73.

II PREMIO ANTONIO ALDAZ

18


Conducting polymer actuators: From basic concepts to proprioceptive systems.Jose G. Martínez.

Sensor and Actuator Systems, Department of Physics, Chemistry and Biology (IFM), Linköping University, 58183 Linköping (Sweden).

Designers and engineers have been dreaming for decades about motors sensing, by themselves, working and surrounding conditions, as biological muscles do originating proprioception. The potential evolutions of self-supported films of conducting polymers or conducting polymers (polypyrrole, polyaniline) coating different microfibers sense working mechanical, thermal, chemical or electrical variables during their oxidation/reduction. Also, the evolution of the muscle potential from electrochemi-cal artificial muscles based on electroactive materials (such as intrinsically conducting polymers), and driven by constant currents, senses, while working, any variation of the mechanical (trailed mass, obstacles, pressure, strain or stress), thermal or chemical conditions of work. One physically uniform artificial muscle includes one electrochemical motor and several sensors working simultaneously under the same driving reaction. Actuating (current and charge) and sensing (potential and energy) magnitudes are present, simultaneously, in the only two connecting wires and can be read by the computer at any time. From basic polymeric, mechanical and electrochemical principles a physicochemical equation describing artificial proprioception has been developed [1]. It includes and describes, simultaneously, the evolution of the muscle potential during actuation as a function of the motor characteristics (rate and sense of the movement, relative position, and required energy) and the working variables (temperature, electrolyte concentration, mechanical conditions and driving current). By changing working conditions experimental results overlap theoretical predictions. The ensemble computer-generator-muscle theoretical equation constitu-tes and describes artificial mechanical, thermal and chemical proprioception of the system. Proprioceptive tools and most intelligent zoomorphic or anthropomorphic soft robots can be envisaged. The author acknowledges the funding received from Carl Tryggers Stiftelse för Vetenskaplig Forskning.

References:1. T.F. Otero, J.G. Martinez, Physical and chemical awareness from sensing polymeric artificial muscles. Experiments and modeling, Prog. Polym. Sci. 44 (2015) 62–78.

ORAL CONTRIBUTIONS


Stable Light-Emitting Electrochemical Cells Based on Ir(III) Complexes as Electroluminis-cent Materials.Enrique Ortí.

Instituto de Ciencia Molecular, Universidad de Valencia, 46980 Paterna (Valencia), Spain.

Ionic transition-metal complexes (iTMCs) are used as the electroluminescent material in light-emitting electrochemical cells (LECs). Since the iTMC material simultaneously satisfies the requirements of electron and hole injection, charge transport, and luminescence, LECs are much simpler devices than organic light-emitting diodes (OLEDs). LECs imply the implementation of an electroactive monolayer processed from solution instead of the multilayer structure of vapor-deposited materials used in OLEDs. Additionally, due to their operation mechanism, air-stable electrodes can be used in LECs, which allows a non-rigorous encapsulation of the device. The industrial implementation of LECs for lighting applications is, however, limited by their short lifetimes and color gamut.

The major breakthroughs concerning color, efficiency, turn-on time, and stability in iTMC-based LECs have been achieved using heteroleptic Ir(III)-iTMCs, which incorporate two negatively charged cyclometalated C^N ligands and one neutral N^N ancillary ligand (see Figure).[1] In this presentation we discuss how the performance of the device is improved by appropriate tuning of the photophysical and electrochemical properties of the electroluminescent iTMC. The discussion is made on the basis of DFT/TD-DFT calculations and mainly focusses on different strategies to improve the electrochemical stability of the reduced/oxidized species and to increase the lifetime and efficiency of the devices. By modifying the molecular structure of the iTMC, highly-stable and efficient LECs have been obtained simultaneously presenting high luminance and efficiency, short turn-on time, and high stability with lifetimes over 4000 hours. The electrochemical stability of the doped species and the nature of the emitting triplet state has been controlled by modifying the chemical structure of the ancillary ligand.[2,3] Theore-tical calculations are especially useful in investigating the relative energy and the electronic nature of the excited states and in systematizing the effect that structural modifications have on the electrochemical and emission properties.

References:1. R. D. Costa, E. Ortí, H. J. Bolink, F. Monti, G. Accorsi and N. Armaroli, Angew. Chem. Int. Ed. 2012, 51, 8178.2. C. D. Ertl, C. Momblona, A. Pertegás, J. M. Junquera-Hernández, M.-G. La-Placa, A. Prescimone, E. Ortí, C. E. Housecroft, E. C. Constable, H. J. Bolink, J. Amer. Chem. Soc. 2017, 139, 3237.3. M. Martínez-Alonso, J. Cerdá, C. Momblona, A. Pertegás, J. M. Junquera-Hernández, A. Heras, A. M. Rodríguez, G. Espino, H. Bolink, E. Ortí, submitted.

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Novel dual microelectrode probes for improved chemical imaging of corroding surfaces using Scanning Electrochemical Microscopy.B.M. Fernández-Pérez.

B.M. Fernández-Pérez1, D. Filotás2, J. Izquierdo1, L. Nagy2, G. Nagy2, R.M. Souto1

1 Departamento de Química, Universidad de La Laguna, Avda. Astrofísico Fco. Sánchez s/n, 38207, La Laguna (Tenerife). 2 G.I. Sistemas de Integración Energética, Instrumentación y Protección, Universidad de Las Palmas de Gran Canaria, Campus de Tafira s/n, 35017, Las Palmas de G. C. (Gran Canaria).

The acquisition of spatially-resolved information from corrosion processes is crucial for the development of efficient protection methods. Therefore, the scanning electrochemical microscopy (SECM) is becoming an essential tool in this field [1]. In general, amperometric microelectrodes are the usual sensing probes in SECM studies, though spatially-resolved pH measurements also provide information regarding the allocation of anodic and cathodic regions [2]. Besides micropipette type pH sensors [3], miniaturized metal/metal oxide type electrodes have been employed in local pH measurements [4]. On the other hand, Mg2+ and Zn2+ion-selective microelectrodes (ISME) have also been employed as SECM sensing probes in galvanic corrosion studies [5]. As result, various probes are currently available for operation in SECM, though their combined use for the characterization of a given corrosion process usually implies probe exchange. The latter severely limits the precision of the measurement device as to image the same spot on the substrate, and prevents simultaneous in situ characterization of these dynamic systems.

These drawbacks can be solved using multi-barreled microelectrodes. In this paper we describe the development of two dual microelectrode probes for SECM. The first probe allows simultaneous monitoring of the concentration distributions of various species of interest using potentiometric operation in SECM, whereas the second has been designed for combined amperome-tric/potentiometric operations. We demonstrate that the new experimental approaches proposed here efficiently distinguish domains with different electrochemical activity in galvanic corrosion reactions and allow simultaneous quantification of the ionic species participating in the processes.

References:1. M.B. Jensen, D.E. Tallman, in: A.J. Bard, C. Zoski (Eds.), Electroanalytical Chemistry: A Series of Advances, Vol. 24, CRC Press, Boca Raton, 2012, p. 171.2. R.M. Souto, J. Izquierdo, J.J. Santana, A. Kiss, L. Nagy, G. Nagy, in: A. Méndez-Vilas(Ed.), Current Microscopy Contributions to Advances in Science and Technology, Vol. 2, Formatex Research Center, Badajoz, 2012, p. 1407.3. E.A. Zdrachek, A.G. Karotkaya, V.A. Nazarov, K.A. Andronchyk, L.S. Stanishevskii, V.V.Egorova, M.G. Taryba, D. Snihirova, M. Kopylovich, S.V. Lamaka, Sensor. Actuat. B-Chem.207 (2015) 967.4. J. Izquierdo, L. Nagy, Á. Varga, J.J. Santana, G. Nagy, R.M. Souto, Electrochim. Acta 56(2011) 8846.5. J. Izquierdo, L. Nagy, I. Bitter, R.M. Souto, G. Nagy, Electrochim. Acta 87 (2013) 283.


Síntesis y caracterización de MPM para su uso en electrolitos de baterías de flujo Zn-Br.Uxua Jiménez Blasco.

Uxua Jimenéz Blasco1, Eduardo Moreno Campo1, Maura Cólera Palacios1, Pilar Díaz Carrasco2, Álvaro Caballero Amores2

1 Jofemar S.A., Ctra Marcilla km 2, 31350 Peralta (Navarra).2 Dpto. Química Inorgánica e Ingeniería Química Universidad de Córdoba, Edificio Marie Curie-1ª planta Campus. Rabanales, 14014 Córdoba (Andalucía).

El presente trabajo se engloba dentro del proyecto SunFloWers cofinanciado por el CDTI y el Fondo Europeo de Desarrollo Regional (FEDER) con el sello EUREKA, que se está llevando a cabo en la empresa Jofemar y cuyo objetivo principal es el diseño, desarrollo y testeo de baterías de flujo Zn-Br modulares con una capacidad de 10 KWh, para aplicaciones solares, eólicas y microrredes residenciales. En este proyecto se está desarrollando un módulo base mejorado, totalmente configurable y adapta-ble a la demanda y especificaciones del cliente, optimizando la batería de 6kWh desarrollada en el proyecto anterior, Flow Grid.

El electrolito es uno de los componentes principales de las baterías de flujo, lo que hace que su estudio y mejora, sea necesario para la optimización general de la batería. En la formulación de los electrolitos, se hace necesaria la adición de sales complejan-tes que capturen el Br2 liberado durante la carga y como consecuencia, se forma una fase inmiscible con mayor densidad que el electrolito. Este proceso debe ser reversible, ya que durante la descarga, la sal complejante tiene que liberar el Br2 capturado anteriormente. Las sales basadas en morfolinio han mostrado ser eficientes en este aspecto, por lo que se ha sintetizado y caracterizado la sal MPM (metilpropilmorfolinio) para analizar su comportamiento.

Las principales fases que se han realizado para definir y optimizar los electrolitos son:

1. Síntesis y optimización del proceso de Bromuro de N-metil-N-propilmorfolinio (MPM) (imagen 1)

Imagen 1. Esquema de la síntesis de MPM.

2. Caracterización preliminar de MPM:

a. Caracterización estructural (RMN, FTIR-ATR y HPLC-MS).

3. Caracterización preliminar del electrolito:

a. Medida de parámetros físico-químicos (pH, conductividad eléctrica, densidad y visco- sidad).

b. Determinación de la composición del electrolito.

i. Determinación de cloruros y bromuros (valorador).

ii. Determinación de zinc (métodos gravimétricos).

4. Análisis de su comportamiento durante y tras el ciclado en celda.

Una vez caracterizado inicialmente el electrolito se introduce en una celda estándar para realizar el ciclado de carga/descar-

ga simulando las condiciones que va a experimentar en uso en la batería, midiéndose:

a. Tensión de la celda.

b. Temperaturas alcanzadas durante su ciclado.

c. Eficiencias obtenidas durante su ciclado.

d. Análisis de la composición del electrolito tras el ciclado.

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The influence of 1.3.4 thiadiazole 2.5 dithiol (DMTD) on corrosion of copper in 0.1M NaNO3 Solution.Siham Echihi.

Siham Echihi1,2 *, Nisrine Benzbiria1, Wafaa Qafsaoui1, Mohamed Tabyaoui2, Abdellah Guenbour2

.1 Laboratory of Water and Environment, Faculty of Sciences of El jadida, BP 20, 24000 El jadida, Morocco.2 Laboratory of Nanotechnology, Materials, and the Environment, Mohammed V-Agdal University, Faculty of Science, 4 Av. Ibn Battouta, B.P. 1014 RP, M-10000 Rabat, Morocco.

Corrosion of copper and its inhibition by 1.3.4 thiadiazole 2.5 dithiol (DMTD) have been investigated in 0.1M NaNO3 solution using Potentiodynamic polarization (PDP), Electrochemical impedance spectroscopy (EIS), Scanning electron microscopy (SEM) along with Energy dispersive (EDX), Atomic absorption spectroscopy (AAS) and Ion chromatography (IC).

PDP measurements showed that the presence of DMTD significantly decreases anodic, cathodic, and corrosion currents in the studied solution with more pronounced effect on cathodic domain and the inhibition efficiency decreases with increasing the temperature.

EIS measurements indicate that the values of polarization resistance and inhibition efficiency tend to increase by increasing the immersion time inhibitor.

SEM/EDX measurements revealed that DMTD is adsorbed on the copper surface at open-circuit potentials, preventing copper from being corroded by forming a protective layer on its surface.

IC and AAS analysis results showed that the concentrations of nitrate ions and copper(II) ions in 0.1M NaNO3 increased and decreased, respectively, after the corrosion process, when 10-2M of DMTD is present in the solution.

References:1. M. Scendo, Inhibition of copper corrosion in sodium nitrate solutions with nontoxic inhibitors, Corrosion Science 50 (2008) 1584–1592 2. W. Qafsaoui, H. Takenouti, Corrosion protection of 2024-T3 aluminium alloy by electro polymerized 3-amino 1,2,4-triazole in sulphate solution containing chloride, Corrosion Science 52 (2010) 3667.3. W. Qafsaoui, H. Huet, H. Takenouti, Analysis of the inhibitive effect of BTAH on localized corrosion of Al 2024 from electrochemical noise measurements, Journal of the Electrochemical Society 156 (2009) C67.4. M. Kendig, M. Hon, J. Sinko, Inhibition of oxygen reduction on copper in neutral sodium chloride corrosion inhibition – non ferrous metals, ECS Transactions 1 (2006) 119.


Modificación de recubrimientos comerciales para la mejora de su comportamiento anticorrosivo y medioambiental.Vicente Mena.

V. F. Mena1,2, A. Betancor-Abreu1, J. J. Santana2, R. M. Souto1

1G.I. Electroquímica y Corrosión, Universidad de La Laguna, Avda. Astrofísico Fco. Sánchez s/n, 38207, La Laguna (Tenerife).2G.I. Sistemas de Integración Energética, Instrumentación y Protección, Universidad de Las Palmas de Gran Canaria, Campus de Tafira s/n, 35017, Las Palmas de G. C. (Gran Canaria).

La corrosión es un grave problema económico y una plaga ecológica, puesto que, las reparaciones derivadas de la corrosión ascienden a cerca del 5% del Producto Interior Bruto de los países occidentales, China e India [1]. Con el objetivo de proteger los metales contra la corrosión, existen diversas vías de actuación, entre las que se encuentra la aplicación de recubrimientos orgánicos, cuya función fundamental consiste en actuar como barrera física frente al acceso de agua, oxígeno e iones presen-tes en ésta, a la interfase metal/recubrimiento, impidiendo la activación de las reacciones electroquímicas de corrosión. El desarrollo de nuevas sustancias respetuosas con el medio ambiente, o la modificación de los actuales recubrimientos comercia-les destinados a la protección contra la corrosión, es un tema de gran importancia tanto para el sector industrial como para el sector del desarrollo de recubrimientos en todas sus etapas. Las sustancias que se vienen usando como inhibidores de la corrosión suelen tener efectos contaminantes con el entorno natural que lo rodea, debido a las cantidades en exceso con las que se suele trabajar, lo que conlleva su vertido descontrolado [2].

En este trabajo se presenta, como alternativa a las soluciones comerciales actuales, el encapsulado de inhibidores de la corrosión de contrastada eficacia, en partículas mesoporosas de sílice. Esta tecnología permite la liberación controlada de la sustancia activa, la acción localizada en las primeras etapas de la corrosión a nivel micro, así como la disminución de la cantidad de inhibidor necesario para una adecuada protección [3]. Con el objetivo de evaluar el comportamiento de las formulaciones propuestas, se hace uso de técnicas electroquímicas clásicas, técnicas de microscopía electroquímica de barrido, y técnicas de caracterización de superficies.

Referencias:1. M.V. Biezma, J.R. San Cristóbal, Corros. Eng. Sci. Technol. 40 (2005) 344. 2. D. Grigoriev et al., Surf. Coat. Technol. 303 (2016) 299.3. M.F. Montemor, Surf. Coat. Technol. 258 (2014) 17.

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Plataformas genosensoras electroanalíticas para seguridad alimentaria.V. Ruiz-Valdepeñas.

V. Ruiz-Valdepeñas Montiel1, R.M. Torrente-Rodríguez1, E. Povedano1, E. Vargas1, M.L. Gutierrez2, Á.J. Reviejo1, C. Cuadrado3, R. Linacero2, F. Javier Gallego2, S. Campuzano1, J.M. Pingarrón1

1 Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, Madrid, 28040, Spain. E-mail: [email protected] 2 Departamento Genética, Facultad de Ciencias Biológicas, Universidad Complutense de Madrid, Av. Complutense s/n, 28040, Madrid, Spain. 3 Departamento de Tecnología de Alimentos, SGIT-INIA, Ctra. Coruña km 7.5, 28040 Madrid, Spain.

Según el Comité de Seguridad Alimentaria Mundial de las Naciones Unidas, la inocuidad de los alimentos se define como el acceso a alimentos suficientes, seguros y nutritivos que satisfagan las necesidades energéticas y las preferencias alimentarias y económicas. Hoy en día, el término seguridad alimentaria se aplica en todas las etapas que experimentan los alimentos hasta que llegan a nuestras mesas, con el fin de garantizar alimentos de calidad aptos para el consumo y libres de patógenos, contaminantes o alérgenos. En el ámbito de la seguridad alimentaria y para contribuir a la máxima satisfacción y protección al consumidor, existe una gran demanda de metodologías sencillas que permitan la determinación rápida y fiable de alérgenos y fraudes alimentarios.

La alergia alimentaria es un problema emergente de salud pública. Particularmente, la avellana es uno de los frutos secos alergénicos más peligrosos asociados con reacciones de hipersensibilidad graves según el Codex Alimentarius y la Comisión Europea. Los principales métodos analíticos de los que se dispone para la determinación de alérgenos se pueden clasificar en ensayos de proteínas o en técnicas de ADN. Sin embargo, puesto que los procesados aplicados a cierto tipo de alimentos pueden desnaturalizar parcial o totalmente los alérgenos proteicos, la determinación selectiva de fragmentos específicos de genes codificantes se propone como una alternativa atractiva para la detección de alérgenos en matrices alimentarias procesa-das. En esta comunicación se presentará una novedosa plataforma genosensora amperométrica para la determinación sensible y selectiva de cualquier variedad de avellana, basada en un formato de hibridación tipo sándwich con sondas biotinila-das específicas de un fragmento característico del gen Cor a 9 sobre micropartículas magnéticas y en una estrategia nueva de amplificación llamada PCR exprés [1].

También resulta de especial relevancia en la actualidad la detección de fraudes alimentarios en productos cárnicos, Aunque la presencia de diferentes tipos de carne en otros productos de origen animal no suelen representar un riesgo para la salud, son los consumidores quienes deben elegir en función de su estilo de vida, costumbres o creencias, qué es lo que consumen. En este sentido y a raíz de los escándalos surgidos en Europa de adulteraciones con carne de caballo, también se expondrán los aspectos más relevantes de una plataforma genosensora desarrollada para la detección amperométrica de carne de caballo, basada en la hibridación selectiva de una sonda de captura de ARN biotinilada específica de un fragmento característico de la región D-loop del ADN mitocondrial de caballo y un formato de amplificación de respuesta que implica el uso combinado de un anticuerpo específico a heterohíbridos de ADN-ARN y una proteína bacteriana conjugada con un homopolímero de HRP. Esta nueva metodología permite discriminar claramente entre muestras de carne de ternera sin contaminar y contaminadas con 0.5% (p/p) de carne de caballo (nivel de detección exigido por la Comisión Europea) en tan sólo 60 minutos, empleando directamente lisados mitocondriales, sin necesidad de extraer previamente el ADN o amplificarlo mediante PCR.

References:1. V. Ruiz-Valdepeñas Montiel et al. Sensors and Actuators B 2017, 245, 895-902.


Nano-carbon materials for the negative plates of Lead Acid Batteries in Micro Hybrid applications.Pilar Ocón.

M. Blecua1, E. Fatas1, P. Ocon1, B. Gonzalo2, J. Valenciano3, F. de la Fuente3, F. Trinidad3

1Universidad Autónoma de Madrid, Depto. de Química Física Aplicada, C/Francisco Tomás y Valiente 7, 28049, Madrid, Spain.2GAIKER Centro Tecnológico, Polígono Parque Tecnológico, Ed. 202, 48170 Zamudio, Vizcaya, Spain.3Exide Technologies, R&D Centre, Conde de Romanones 30, 19200 Azuqueca de Henares, Spain.

One of the main objectives of the Lead Acid Batteries (LAB) is to work in the Micro Hybrid vehicle as power supply source, where batteries must be able to accept the charge of the regenerative braking and to work in High Rate Partial State of Charge (HRPSoC) conditions. In this conditions, lead sulfate (PbSO4) crystal are progressively accumulated on the lead surface, leading to the battery failure. In order to avoid this sulfation, carbon materials can be added to the Negative Active Material (NAM), where they enhance the electrochemical active area, and hence increase the activated sites where charging reactions can take place. In this way they improve the charge acceptance of the negative plates, hampering the creation of irreversible PbSO4 crystals, and prolonging the cycle life of LAB working in HRPSoC conditions. However, carbon materials also catalyse the Hydrogen Evolution Reaction (HER), which increases the water loss and lead to the battery failure. Several studies have been carried out with different carbon materials [1-4] demonstrating the promotion of reversible PbSO4 when they are to the NAM, but also the improvement on HER rate.

In the current study, nano carbon black and graphitized Carbon Nanofibers were used as additives for the NAM, giving rise to four different mixtures. Negative plates of these mixtures were made at the laboratory. 2 V / 1 Ah small lead acid cells were prepared with one negative / two positive plate’s assembly using a glass mat separator. This assembly was compressed between two methacrylate sheets, and submerged in H2SO4 (1.28 g cm-3). The cells fulfilled several electrical tests: capacity, cold-cranking ability, initial charge acceptance, negative polarization and Cycle at Partial State of Charge (PSoC). NAM morphology and particle size studies were determined by scanning electron microscope (SEM, S-3000N). Two magnifications of the samples were available: 3000x and 6000x. PbSO4 content was determined by an ELTRA CS-800 analyzer.

Nano carbon black would be deposited on the lead skeleton surface where they improve the electrochemical active area of the NAM, while graphitized Carbon Nanofibers would be able to create a uniform conductive network inside the NAM. On the one hand, nano carbon black is able to enhance the charge acceptance of the negative plates, but increase the water consumption and fails to avoid the sulfation of the negative plate when it is working in PSoC conditions. On the other hand, graphitized Carbon Nanofibers fail to improve the charge acceptance of the negative plates, but they are able to prolong the cycle life of the cells, namely that these fibers are able to distribute the current throughout the whole negative plate during PSoC operation.

References:1. D. Pavlov, P. Nikolov, T. Rogachev. Journal of Power Sources. 196 (2011) 5155–5167.2. P.T. Moseley, R.F. Nelson, A.F. Hollenkamp. Journal of Power Sources. 157 (2006) 3–10.3. J. Valenciano, A. Sánchez, F. Trinidad, A.F. Hollenkamp. Journal of Power Sources. 158 (2006) 851–863.4. S.W. Swogger, P. Everill, D.P. Dubey, N. Sugumaran. Journal of Power Sources. 261 (2014) 55–63.

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S-doped hydrochar addition to based chitosan/poly(vinyl) alcohol ion-exchange membranes with enhanced physicochemical and electrochemical properties.Leticia García-Cruz.

Leticia García-Cruz1,Tiago Duarte2, Ana P. Carvalho2, Vicente Montiel1, Jesús Iniesta1

1 Department of. Physical Chemistry of Alicante University, Ctra. San Vicente del Raspeig s/n, 03690 Alicante (Spain). 2 CQB and Department of Chemistry and Biochemistry, Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016 Lisbon (Portugal).

The development of synthetic ion-exchange membranes have received especial attention during the last years, encouraged by their structural and composition possibilities and physicochemical properties with a broad range of applications and processes. The membranes present a significant influence on performance of (i) energy conversion and electrochemical energy-storage devices where membranes are used as either solid polymer electrolyte or simply separator, and of (ii) (bio) sensors where the polymeric structure acts e.g. as coating protector of biomolecules. Membranes are also used in industrial applications, for instance, for water purification, gas separation processes, and electrocatalytic supports. Recently, the incorporation of carbon materials as a filler into membrane matrices is also becoming a hot topic in the field of materials science research. In this sense, advantages have been demonstrated on the improvements related to adsorption processes, separation and filtration in medici-ne or water remediation and electrochemical performance, among others.

This communication is focused on the feasibility of using membranes based on eco-friendly polymers such as chitosan (CS) and poly (vinyl) alcohol (PVA) as polymer backbone containing S-doped hydrochars as fillers. As well is mentioned in the literature, PVA mixed with CS ameliorates the mechanical, chemical and electrochemical features of CS in ion-exchange membranes. Lately, we have demonstrated [1] that the incorporation of graphene oxide nanosheets into a CS:PVA matrix led to a reinforced structure with enhanced thermal stability, good alcohol permeability, and a high per-formance comparable to anion-exchange commercial membranes when it was used as alkaline solid polymer electrolyte into the electrochemical reactor. By following a similar procedure, this communica-tion explores the performance of blending CS and PVA in a 50:50 ratio doped with 1 wt.% of different kinds of S-doped hydrochars, that are activated in basic medium. A physicochemical characterization of S-doped hydrochars based CS:PVA membranes have been carried out by optical microscopy, scanning electron microscopy (SEM), correlating the synthesis method with the membrane morpholo-gies. XRD, XPS and thermal analysis have supported the benefi-cial of incorporating S-doped hydro-chars within the CS:PVA matrix. Besides, different S-doped hydrochars have been electro-chemically characterized by cyclic voltammetry. Finally, the anion conductivities of the membranes have been compared in terms of the carbon material nature by using electrochemical impedance spectroscopy (EIS).

References:[1] L. García-Cruz, C. Casado-Coterillo, A. Irabien, V. Montiel, J. Iniesta, High performance of alkaline anion-exchange membranes based on Chitosan/Poly(vinyl) alcohol doped with graphene oxide for the electrooxidation of primary alcohols, C Journal of Carbon Research 2 (2016) 10.


Self-supported films of conducting polymers as bending Monolayer Artificial Muscle.Laura Valero.

Laura Valero1,2, Toribio F. Otero2, Victor Pascual2

1 Universidad Autónoma del Estado de México, Engineering School, Toluca 50000 México.2 Universidad Politécnica de Cartagena, Laboratory of Electrochemistry, Intelligent Materials and Devices, 30203, Cartagena, Spain.

The study and electrochemical characterization of pPy_DBS monolayer bending actuators corroborates the reaction driven expulsion of cations from the conducting polymer to the electrolyte during oxidation and its entrance during reduction, in the full potential range. The actuator is a faradaic device controlled by the driving reaction: the rate of the angular movement is under linear control of the current driving the reaction and the described angle is under linear control of the consumed charge.

A bending monolayer artificial muscle is presented and characterized giving the highest coulo-dynamic efficiency described for artificial muscles. Transversal cross-linking gradient attained during the film electropolymerization are identified as origin of the reaction-driven muscular movement. This oversimplified polymeric motor for engineering applications saves extra energy required to bend and trail inactive layers from bilayer or multilayer classical structures.

The electrogenerated film was immersed in 0.1M LiClO4 aqueous solutions where it was submitted to consecutive potential sweeps: this is a self-supported PPy-DBS monolayer electrode. After of some adapting cycles almost stationary voltammetric (potential-current) responses were at-tained from the PPy-DBS, those bending movements reveal a greater electoactivity, and large shrink-ing/swelling changes during oxidation/reduction, respectively, of the film side that was on the electro-lyte side during its electrogeneration. The other side of the conducting polymer film present at the pol-ymer metal interface during its electrogeneration follows now a minor electroactivity.

From the recorded video-frames the angle described by the free end of the monolayer muscle as a function of the muscle potentials during the potential sweep, i.e., the dynamo-voltammetric (angle-potential) response, was attained. Those reaction-driven bending movements indicate a transversal shrinking asymmetry during the PPy-DBS oxidation and a transversal swelling asymmetry during the monolayer reduction

The use of bending self-supported films of conducting polymers should supposed to decrease the power consumption and simplify the designs for robotic applications.

References:1. T. F. Otero, Polym. Rev. 2013, 53, 311.2. E. Smela, Adv. Mater. 2003, 15, 4813. T. F. Otero, Conducting Polymers: Bioinspired Intelligent Materials and Devices, RSC, 20154. L. Valero Conzuelo, J. Arias-Pardilla, J. V. Cauich-Rodriguez, M. Afra Smit, T. Fernandez Otero, Sensors 2010, 10, 2638

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Color y espectro-electro-gravimetría de Poli-(Rojo Neutro).Francisco Vicente.

Francisco Vicente, José J. García-Jareño, David Ferrús, Alejandro Cuenca, Jerónimo Agrisuelas

Departamento de Química Física (Universidad de Valencia), Dr. Moliner 50, 46100 Burjassot (Spain).

El interés científico de los polímeros conductores electrogenerados va creciendo en tanto se conocen nuevas aplicaciones tecnológicas. Este trabajo se centra en la electrogeneración de poli-(Rojo Neutro) [1,2], así como su caracterización por métodos ópticos y espectro-electrogravimétricos con el objeto analizar el color de este tipo de materiales y también profun-dizar en el conocimiento de sus propiedades físicas en general.

El propio monómero de Rojo Neutro, frente a otros fenacinas y fenotiacinas, muestra un comportamiento peculiar, ya que en su reducción se genera hidrógeno en mayor proporción a través de una reacción electroquímica secundaria, si bien el mecanismo de polimerización es similar en todos los casos ensayados. El color de las películas de estos polímeros, electro-generados por diferente número de ciclos voltamperométricos sucesivos, puede ser cuantificado mediante el análisis de la toma imágenes ópticas instantáneas o de video [3]. Se ha comprobado que la respuesta de color está afectada por la propia formación de capas pasivas del soporte metálico. No obstante, se pueden deconvolucionar los voltamperogramas sobre electrodos de oro mediante Microbalanza Electroquímica de Cuarzo EQCM-R a las que se ha acoplado un espectrofotóme-tro, pudiéndose separar así las contribuciones de las reducciones de los dobles enlaces electroactivos del polímero de la reacción secundaria de evolución de hidrógeno.

La información obtenida es de interés para la elaboración de sensores, dispositivos almacenamiento de carga, pinturas protectoras decorativas, membranas y dispositivos electromecánicos, así como para comprender mejor los procesos físico-químicos que se producen al aplicar una perturbación eléctrica a este tipo de material polimérico.

Referencias: [1] D. Benito, C. Gabrielli, J.J. García-Jareño, M. Keddam, H. Perrot, F. Vicente, Study by EQCM on the voltammetric electrogeneration of poly(neutral red). The effect of the pH and the nature of cations and anions on the electrochemistry of the films, Electrochimica Acta. 48 (2003) 4039–4048. doi:10.1016/S0013-4686(03)00561-9.[2] D. Benito, J.J. García-Jareño, J. Navarro-Laboulais, F. Vicente, Electrochemical behaviour of poly(neutral red) on an ITO electrode, J. Electroanal. Chem. 446 (1998) 47–55. doi:10.1016/S0022-0728(97)00565-2. [3] J. Agrisuelas, J.J. García-Jareño, E. Perianes, F. Vicente, Use of RGB digital video analysis to study electrochemical processes involving color changes, Electrochem. Commun. 78 (2017) 38-42. doi:10.1016/j.elecom.2017.04.001.

Agradecimientos: Este trabajo ha sido financiado por CICyT-FEDER (Proyecto CTQ2015-71794-R).

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Efecto del Bi2O3 sobre la superficie del ánodo durante la descarga de baterías Zn/aire. Estudio de XRD “in situ” con radiación sincrotrón.Antonio J. Fernández Romero.

Florencio Santos1, José Abad1, María Vila2, Germán R. Castro2, Antonio J. Fernández Romero1

1 Grupo de Materiales Avanzados para la Producción y Almacenamiento de Energía, Universidad Politécnica de Cartagena, Aulario II, Campus de Alfonso XIII, 30203 Cartagena, Spain.2 SpLine Spanish CRG, European Synchrotron Radiation Facility, Grenoble, France.

En este trabajo se ha analizado la superficie del ánodo durante la descarga de baterías Zn/aire, mediante Difractometría de Rayos X, utilizando radiación sincrotrón. Los experimentos se han llevado a cabo haciendo uso de una celda electroquímica fabricada por nuestro grupo para realizar las medias “in situ” (Figura 1). Se ha analizado e distintos ánodos, compuestos por Zn puro o mezclas de Zn con Bi2O3 en distintas proporciones. El electrolito es una disolución acuosa de KOH 6M.

Los difractogramas evidencian la rápida formación de Bi metal al sumergir los electrodos en la disolución y la dependencia de formación de ZnO con la proporción de Bi2O3.

Referencias:1. J.W. Gallaway. et al., J. Electrochem. Soc. 161 (2014) A275-A284

Agradecimientos: Al Ministerio de Economía y Competitividad (Ref. ENE2013-48816-C5-3-R and ENE2016-79282-C5-5-R). Se agradece la invitación y el apoyo económico por parte de la Red E3TECH (CTQ2015-71650-REDT)

Fig 1. Batería Zn/air montada en el equipo para realizar las medidas XRD con radiación Sincrotrón.

Fig. 2 XRD sincrotrón in situ de la descarga de una batería Zn/aire usando un electrodo de Zn-Bi2O3.

Bi Bi

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40


Iron oxide nanostructures for photoelectro-chemical water splitting: Study of the influence of hydrodynamic conditions during electrochemical anodization.Bianca Lucas-Granados.

Bianca Lucas-Granados, Rita Sánchez-Tovar, Ramón M. Fernández-Domene, José García-Antón

Ingeniería Electroquímica y Corrosión, Instituto Universitario de Seguridad Industrial, Radiofísica y Medioambiental, Universitat Politècnica de València.

Nowadays, there is an increasing demand of renewable sources for energy production in order to mitigate global warming. Nanostructures of different materials are interesting for being used as photocatalysts in electrochemical water splitting using sunlight. Iron, mainly in its hematite form (α-Fe2O3), is one of the best options due to its properties, such as suitable band gap (~2.1 eV), abundance, non-toxicity and low cost. Electrochemical anodization is one of the methodologies used for the synthe-sis of iron oxide nanostructures. In this study, electrochemical anodization of iron was carried out under different controlled hydrodynamic conditions and different morphological, structural, electrochemical and photoelectrochemical techniques were used in order to characterize the nanostructures.

Figure 1. Scheme of the process including the electrochemical anodization cell with a Rotating Disk Electrode (RDE), FE-SEM images of the nanostructure and photoelectrochemical water splitting plot.

Iron rods were connected to a rotating disk electrode in order to apply different rotation speeds to the electrode in the range of 0 to 3000 rpm during the anodization as Figure 1 shows. Results showed that electrochemical anodization of iron at 1000 rpm resulted in a nanotubular structure that achieved a photocurrent density of ~0.13 mA·cm-2 at 0.54 V (vs. Ag/AgCl) in the water splitting measurements. In conclusion, hydrodynamic conditions during anodization modify the morphology of the iron oxide nanostructures and, consequently, enhance their photoresponse as photocatalysts for photoelectrochemical water splitting.

Acknowledgements: Authors thank for the financial support to the Ministerio de Economía y Competitividad (Reference: BES-2014-068713, Project Code: CTQ2013-42494-R), for its help in the Laser Raman Microscope acquisition (UPOV08-3E-012), for the co-finance by the European Social Fund and for the financial support from the Spanish excellence network E3TECH funded by the Ministerio de Economía y Competitividad (MINECO) under project CTQ2015-71650-RD.

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Treatment of hospital wastewater by electrochemical technology.Salvador Cotillas.

Salvador Cotillas1, Engracia Lacasa1, Cristina Sáez2, Pablo Cañizares2, Manuel A. Rodrigo2

1 Departamento de Quí1Department of Chemical Engineering. School of Industrial Engineering. University of Castilla-La Mancha. Avenida de España S/N, 02071. Albacete. Spain.2 Department of Chemical Engineering. Faculty of Chemical Sciences and Technologies University of Castilla-La Mancha. Avenida Camilo José Cela 12,13005. Ciudad Real. Spain.

Water pollution is one of the main problems in our society, particularly in a country like Spain where the lack of water may even limit their social and economic development. The water pollution can come from both natural and human activities, being the latter the most dangerous since the presence of non-natural substances in the environment can dangerously affect life cycles of living beings. For this rea-son, it is necessary to carry out a suitable management of the generated wastes, in order to minimize the adverse effects on health and the environment. One of the wastes that can generate a problem in society are the effluents coming from centers and companies in the health sector. Within these sani-tary effluents, urine is one of the most dangerous sources of dissemination of anthropogenic sub-stances into the aquatic environment, being able to differentiate between two important aspects: on the one hand, the spread of drugs or their metabolites, whose effects can be unknown and unex-pected and, on the other hand, the potentially dangerous pathogens as fungi, bacteria or viruses. Therefore, it is necessary to develop clean and efficient technologies that allow the removal of both, pharmaceuticals and microorganisms, in wastewater.

In this context, conductive-diamond electrochemical oxidation (CDEO) has been proved efficient for the removal of several organics such as pesticides, hormones, personal care products, reaching the total mineralization of the organic matter. During this process, higher concentrations of hydroxyl radi-cals and other oxidants are electrochemically generated over the anode surface and they are the main responsible species of the degradation process. Likewise, CDEO allows to remove the microor-gan-isms present in wastewater, applying low current densities. In this case, chlorides naturally present in wastewater are oxidized over the anode surface favouring the production of free and combined chlo-rine species which attack to microorga-nisms, causing their death.

With this background, the main aim of the present work is to evaluate the application of CDEO for the removal of pharmaceu-ticals and microorganisms in synthetic urine media. First of all, the influence of the initial concentration (1-10 mg dm-3) of two different pharmaceuticals (antibiotic and anti-inflammatory) were evaluated at current densities within the range 10-100 mA cm-2. The degradation of urine compounds was also followed during the process (urea, uric acid and creatinine). Next, the removal of microorganisms in urine media was studied at different low current densities (1-10 mA cm-2). Specifically, Escheri-chia coli and Pseudomonas aeruginosa were selected as bacterial indicators. Results show that it is possible to attain the complete mineralization of the organic matter during the treatment of synthetic urine polluted with pharmaceuticals. The process efficiency of the pharmaceuti-cals removal is higher when applying low current densities (10 mA cm-2). On the other hand, CDEO allows to completely remove microorganisms in urine media. In addition, it is possible to attain a com-plete mineralization of urine compounds applying very low current densities (1 mA cm-2).

Acknowledgements:Financial support from the Spanish Ministry of Economy, Industry and Competitiveness and European Union through project CTM2016-76197-R (AEI/FEDER, UE) is gratefully acknowledged. CYTEMA E2TP is also acknowledged for the grant to Dr.

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Nanotubos de carbono de pared simple funcionalizados con viológeno como etiqueta para inmunoensayos electroquímicos.Esther Sánchez-Tirado.

Esther Sánchez-Tirado1, Araceli González-Cortés1, P. Yáñez-Sedeño1, F. Langa2, J.M. Pingarrón1

1 Dpto. Química Analítica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid. 28040 Madrid.2 Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), Universidad de Castilla-La Mancha. 45071 Toledo.

Los viológenos son derivados de la 4,4’-bipiridina que exhiben respuestas electroquímicas reversibles a potenciales negati-vos según sus tres principales estados de oxidación V2+ � V+ � V0. La primera reacción es la base para su uso como acepto-res de electrones y mediadores de transferencia electrónica de proteínas, promoviendo el intercambio de electrones con el electrodo [1]. En este trabajo se sintetizó un híbrido V-Phe-SWCNTs para su empleo como etiqueta electroactiva de amplifi-cación de la señal en la preparación de inmunosensores electroquímicos. Por otra parte, el factor de crecimiento transfor-mante beta 1 (TGF-β1) es una citoquina perteneciente a la superfamilia de TGFs que regula varios procesos biológicos. La TGF-β1 está implicada en la respuesta inmune e inflamatoria, y se considera un biomarcador del carcinoma de vejiga, enfermedades renales y fibrosis hepática [2]. La Figura 1 muestra las etapas implicadas en la preparación del inmunosensor para TGF-β1. El anticuerpo de captura biotinilado (Biotin-anti-TGF) se inmoviliza sobre un electrodo de carbono serigrafiado (SPCE) modificado con estreptavidina mediante “grafting” electroquímico, y se establece un ensayo de tipo sándwich con el híbrido previa inmovilización de anti-TGF y peroxidasa (HRP). Tras optimizar las variables experimentales, se obtuvo un calibrado lineal entre 2.5 y 1000 pg/mL TGF-β1, con un límite de detección de 0.95 pg/mL, mil veces inferior al de otra configuración reciente [3]. El inmunosensor presenta una buena reproducibilidad, estabilidad de almacenamiento y elevada selectividad. Además, el tiempo de ensayo es tres horas, inferior al requerido en los kits ELISA comerciales. Finalmente, se demostró la utilidad clínica del inmunosensor mediante análisis directo de dos muestras reales de saliva.

Referencias:1. D. Lee, Y.H. Kim, S. Parkz. Journal of the Electrochemical Society, 2016, 163, G93–G982. M.V. Tsapenko, R.E. Nwoko, T.M. Borland, N.V. Voskoboev, A. Pflueger, A.D. Rule, J.C. Lieske. Clinical Biochemistry, 2013, 46, 1430–14353. Z. Matharu, D. Patel, Y. Gao, A. Haque, Q. Zhou, A. Revzin, Analytical Chemistry, 2014, 86, 8865–8872


Caracterización de Hidrogeles para su aplicación en baterías de Zn/aire.Florencio Santos.

Florencio Santos1, Juan P. Tafur1,2, Antonio J. Fernández Romero1

1 Grupo de Materiales Avanzados para la Producción y Almacenamiento de Energía, Universidad Politécnica de Cartagena, Aulario II, Campus de Alfonso XIII, 30203 Cartagena, Spain.2 Facultad de Ingeniería en Ciencias Aplicadas. Universidad Técnica del Norte. Ibarra, Ecuador.

En esta comunicación se abordará la síntesis de hidrogeles compuestos de PVA y KOH para su aplicación como electrolitos de baterías Zn/aire (Figura 1). La inmersión de estos geles en disolución de KOH provoca su hinchamiento debido a la incorpora-ción de mayor cantidad de disolución al gel. Este hecho supone un aumento considerable de las propiedades conductoras de este electrolito, haciendo más viable su uso en baterías Zn/aire.

Los hidrogeles se han caracterizado haciendo uso de diferentes técnicas electroquímicas y espectroscópicas. Se presentarán resultados de Voltametría Cíclica (Figura 2), Conductividad y Termogravimetría, entre otras. Además, se mostrarán las descar-gas obtenidas para baterías de Zn/aire haciendo uso de estos hidrogeles.

Referencias:1. Choudhury, N. A., Sampath, S., & Shukla, A. K. (2009). Hydrogel-polymer electrolytes for electrochemical capacitors: an overview. Energy & Environmental Science, 2(1), 55-67.

Agradecimientos: Al Ministerio de Economía y Competitividad (Ref. ENE2013-48816-C5-3-R and ENE2016-79282-C5-5-R). Se agradece la invitación y el apoyo económico por parte de la Red E3TECH (CTQ2015-71650-REDT)

Figure 1. Imagen de un hidrogel sintetizado a partir de PVA y KOH.

Figure 2. Voltametría Cíclica de hidrogeles sintetizados. La curva roja corresponde a un hidrogel recién preparado y la azul a otro similar pero mantenido en disolución de KOH durante 48 horas.

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Controlled and sustainable fabrication of WO3 nanoplatelets by anodization using inorganic ligands.Ramón M. Fernández-Domene

Ramón M. Fernández-Domene, Rita Sánchez-Tovar, Bianca Lucas-Granados, José García-Antón

Ingeniería Electroquímica y Corrosión, Instituto Universitario de Seguridad Industrial, Radiofísica y Medioambiental, Universitat Politècnica de València..

Tungstates are “special” ions, since they have a tendency to form condensed, complexed isopolytungstates in acidic media. Eventually, at low pH values (lower than 1), precipitated tungsten acids are obtained. This process, known as polycondensa-tion, has been used in the last years to synthesize WO3 nanostructures for several applications, such as photocatalysis and photoelectrocatalysis for energy and environmental processes, electrochromic devices, etc.

Among the used fabrication procedures, electrochemical anodization is one of the most simple and suitable synthesis methods to obtain ordered nanostructures with high active areas. Electrolytes with fluorides are frequently used for that purpose, since these anions act as complexing agents favoring the formation of tungsten soluble species and their subsequent polycondensation upon reaching supersaturation conditions.

In this study, different complexing agents (fluoride anions and hydrogen peroxide) have been used to fabricate novel WO3 nanostructures for photoelectrochemical applications. Different fluoride and H2O2 concentrations (0-0.2M) have been employed in sulphuric acid media (at 50 ºC) as anodization electrolytes. Anodization of tungsten in the presence of small amounts of H2O2 and under hydrodynamic conditions constitutes a very innovative method to fabricate WO3 nanostructu-res. Moreover, H2O2 is an environmentally-friendly complexing agent (unlike fluorides) because the by-products of its decomposition are just oxygen and water, so the manufacturing process presented here can be regarded as sustainable.

The mechanism of formation and growth of these nanostructures has been related to the amount of complexing agents. For that purpose, Field Emission Scanning Electron Microscopy (FESEM) and photoelectrochemical measurements have been performed. Obtained results show that the shape and size of WO3 nanoplatelets/nanosheets, as well as their photocatalytic performance, can be regulated by the amount of complexing agents present in the electrolyte. The obtained nanostructures have been succesfully tested as photoanodes for water splitting and for the removal of recalcitrant organic compounds, such as methyl orange.

Acknowledgements: Authors thank for the financial support to the Ministerio de Economía y Competitividad (Project Code: CTQ2016-79203-R), for its help in the Laser Raman Microscope acquisition (UPOV08-3E-012), for the co-finance by the European Social Fund and for the financial support from the Spanish excellence network E3TECH funded by the Ministerio de Economía y Competitividad under project CTQ2015-71650-RDT.

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Effect of the water composition on the electrochemical softening method: study of efficiency and characterisation of precipitates.Ignacio Sanjuán.

Ignacio Sanjuán1, David Benavente2, Eduardo Expósito1, Vicente Montiel1

1 Grupo de Electroquímica Aplicada, Instituto Universitario de Electroquímica, Departamento de Química Física, Universidad de Alicante, Apdo. 99, Alicante 03080, Spain. 2 Departamento de Ciencias de la Tierra y del Medio Ambiente, Universidad de Alicante, San Vicente del Raspeig, Alicante 03690, Spain.

In recent years, the affordable clean water resources have suffered a decrease due to an unsustainable consumption. Membra-ne-based technologies like Reverse Osmosis (RO) and Electrodialysis (ED) are being developed and employed to obtain usable clean water from abundant resources like seawater or brackish water. Nevertheless, their application is limited by the costs associated with the concentrate production [1].

Therefore, the augment of the water recovery by these membrane-based techniques is necessary in order to make them cost-effective. Unfortunately, it results troublesome because the consequent volume reduction could give rise to a precipitation of insoluble salts due to the presence of high amounts of scale forming ions (Ca2+, Mg2+ and HCO3-…) in many types of concentrate. That leads to scaling problems like pipe plugging or membrane fouling.

The electrochemical softening method is a useful process which can be employed to reduce the hardness degree of concentra-tes and help to increase the water recovery [2]. This technique is based on the electrolysis of the concentrate. In the cathode, the electroreduction of water leads to an increase of the local pH on the cathode vicinity and, as a result, the deposition of insoluble compounds on its surface. This process presents several advantages like easy maintenance, environmental compatibi-lity and no chemicals addition. However, its application in the desalination practice is still limited because of the high area requirement to achieve an acceptable economic cost. A major system development is thus necessary in order to overcome the technical limitations.

In this regard, the composition of the water to treat is one of the key operational parameters for this process and it must be assessed since concentrates can be of varied nature. In this work, the effect on the hardness removal efficiency by the main parameters of water composition has been evaluated in a 100 cm2 filter-press reactor with a three-dimensional stainless steel wool cathode. Experiments have always been conducted for waters of a fixed high hardness but evaluating the differences in the following composition parameters: alkalinity, Mg/Ca relationship, and the presence of an anti-scalant species; specifically sodium hexametaphosphate. For every experiment, the hardness removal rate has been measured. In addition, the morpholo-gy and composition of the corresponding formed precipitate have been characterised by Scanning Electron Microscopy, X-ray Diffraction and Thermogravimetry coupled to Differential Thermal Analysis. The goal of this study deals with a deeper unders-tanding of the role of each component, how they affect to the process and to the efficiency and finally with the feasibility of each type of concentrate to be treated by this technique. This information contributes to the technique development, in the interest of a future application in the desalination practice.

References: [1] V.G. Gude, Desalination and sustainability - An appraisal and current perspective, Water Res. 89 (2016) 87–106. [2] C. Gabrielli, G. Maurin, H. Francy-Chausson, P. Thery, T.T.M. Tran, M. Tlili, Electrochemical water softening: principle and application, Desalination. 201 (2006) 150–163.

Acknowledgements: Authors would like to acknowledge the invitation and the financial support provided by Red E3TECH (CTQ2015-71650-REDT)

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Nuevas inmunoplataformas electroquímicas para la determinación de biomarcadores cardiacos emergentes.Verónica Serafín.

V. Serafín1, R.M. Torrente-Rodríguez1, M. Batlle2, P. García de Frutos2, P. Yáñez-Sedeño1, S. Campuzano1, J.M. Pingarrón1

1 Departamento de Química Analítica, Facultad de Química, Universidad Complutense de Madrid, Madrid, 28040, España.2 Instituto de Investigaciones Biomédicas August Pi i Sunyer (IDIBAPS), Instituto Thorax España, Departamento de Cardiología, Hospital Clinic de Barcelona, España.

Los biomarcadores cardíacos son sustancias liberadas a la sangre cuando se produce un daño en el corazón. La detección y determinación de estos marcadores es útil para diagnosticar y pronosticar el riesgo de Insuficiencia Cardiaca (IC).

La AXL es una proteína receptora transmembrana tirosina quinasa. Estudios recientes han demostrado la relevancia de esta proteína como un importante biomarcador para la detección temprana de la IC, estableciendo un valor de corte de 71 ng mL-1 para discriminar entre individuos sanos y pacientes con IC. Además, la sobreexpresión de este biomarcador está relacionada con la resistencia a las terapias dirigidas y quimioterapia convencional en diferentes tipos de cáncer. Con objeto de conseguir metodologías sencillas de bajo coste, rápidas y fácilmente implementables en dispositivos POC, en este trabajo se describen por primera vez, tres inmunosensores electroquímicos para la determinación de AXL. Estos consisten en un inmunosensor integrado y dos magnetoinmunosensores basados en el uso de nano- y micropartículas magnéticas.

Todos ellos están basados en formatos de inmunoensayo tipo sándwich, así como en el empleo de electrodos desechables de carbono (SPCEs) y en la inmovilización covalente usando EDC/NHSS sobre soportes que contienen un elevado número de grupos carboxílicos. La determinación se lleva a cabo por amperometría en disoluciones agitadas a -200 mV (vs Ag) tras la adición de H2O2 en presencia de hidroquinona (HQ) como mediador redox.

Tras la optimización de las variables experimentales involucradas en cada una de las tres estrategias, se obtuvieron los calibra-dos correspondientes, que presentan unas características analíticas muy atractivas en todos los casos en términos de sensibili-dad, selectividad y estabilidad, siendo adecuadas para determinar la proteína diana en muestras de suero a niveles clínicamen-te relevantes. Cabe destacar además que todas las metodologías desarrolladas se basan en formatos desechables y presentan la posibilidad de utilizar transductores electroquímicos de pequeño tamaño y portátiles, lo que las convierte en alternativas a los kit ELISA colorimétricos convencionales para el desarrollo de sistemas POC automáticos, con el objetivo de realizar determinaciones descentralizadas de este biomarcador proteico asociado con IC.

References: 1. V. Serafín et al. Sens and Actuat. B, 2017, 240, 1251.2. M. Batlle et al. International Journal of Cardiology, 2014, 173, 402.

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Influence of metallic Na on the electrode/electrolyte interfacial properties of Na-ion batteries.Maider Zarrabeitia.

Maider Zarrabeitia1,2, Miguel Ángel Muñoz-Marquez2, Francesco Nobili3, Teófilo Rojo1,2, Montse Casas Cabanas2

1 Departamento de Química Inorgánica, Universidad del País Vasco UPV/EHU, P.O. Box 664, 48080, Leioa (Basque Country).2 CIC Energigune, Albert Einstein 48, 01510 Vitoria-Gasteiz (Basque Country).3 Scuola di Scienze e Tecnologie – Sezione Chimica, Università di Camerino, Via S. Agostino 1, Camerino (Italy).

The energy demand is constantly increasing and hence, energy storage has become a key factor in terms of efficient genera-tion and distribution. While Li-ion batteries (LIBs) are focused on portable electronics and are postulated as the best choice for the electric vehicle industry owing to their high energy density, Na-ion batteries (NIBs) are becoming an attractive solution for stationary large scale applications [1].

Many lithium analogues have been reported as cathode materials for NIBs [1] however, the challenge is to find alternative anode materials due to the impossibility of Na+ insertion into graphite and formation of a stable Solid Electrolyte Interphase. Na2Ti3O7 is a promising negative electrode for rechargeable NIBs due to its low insertion voltage at 0.3 V vs. Na+/Na and theore-tical capacity of 178 mAh/g [2]. However, its good properties are hampered by the poor capacity retention [3,4,5]. Among several factors that could influence on the electrochemical performance, the electrode/electrolyte interfacial properties are one of them. Moreover, recently it has been reported the instability of metallic Na in organic electrolyte where electrochemical impedance spectroscopy experiments concluded that the interfacial resistance increased upon time in Na/Na cells [6]. Therefo-re, the use of metallic Na as counter and reference electrode in half cell studies is another important issue which can influence on the electrochemical and electrode/electrolyte interfacial properties.

In this work the interfacial properties of Na2Ti3O7 have been investigated by ex-situ X-ray photoelectron spectroscopy (conven-tional XPS and Auger parameter analysis) and electrochemical impedance spectroscopy. The results have been used to check the differences between half cell (using as counter electrode metallic Na) and full cell (using as counter electrode NaFePO4) configuration upon electrochemical cycling.

The obtained results will be thoroughly discussed and will conclude whether the metallic Na is a good counter electrode to study the electrochemical properties of the positive and negative electrode for NIBs.

References: [1] V. Palomares, M. Casas-Cabanas, E. Castillo-Martínez, M.H. Han, T. Rojo, Energy Environ. Sci. 6 (2013) 2312.[2] P. Senguttuvan, G. Rousse, V. Seznec, J.M. Tarascon, M.R. Palacín, Chem Mater. 23 (2011) 4109. [3] A. Rudola, K. Sarava-nan, C.W. Mason, P. Balaya, J. Mater. Chem. A 1 (2013) 2653.[4] H. Pan, X. Lu, X. Yu, Y.S. Hu, H. Li, X.Q. Yang, L. Chen, Adv. Energy Mater. 3 (2013) 1186.[5] J. Nava-Avendaño, A. Morales-García, A. Ponrouch, G. Rousse, C. Frontera, P. Senguttuvan, J.M. Tarascon, M.E. Arroyo-de Dompablo, M.R. Palacín, J. Mater. Chem. A. 3 (2015) 22280.[6] D.I. Iermakova, R. Dugas, M.R. Palacín, A. Ponrouch, J. Electrochem. Soc. 162 (2015) A7060.

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Biomimetic sensor. Polypyrrole redox voltammetric charge senses the electrolyte concentration.Samuel Beaumont.

Samuel Beaumont1, Toribio F.Otero1

1 Laboratory of Electrochemistry Intelligent Materials and Devices. Technical University of Cartagena. ETSII. Campus Alfonso XIII. 30203. Cartagena. Spain.

Electrochemical reactions of conducting polymers, and other electroactive materials, sense the working conditions, mimicking many biochemical reactions involving macromolecules as reactants and originating biological functions. The evolution of the reversible voltammetric charge from a polypyrrole film in aqueous solutions of NaCl is a function of the salt concentration. The amplitude of the reaction involving conformational movements of the reacting polymeric chains (polymeric motors) is a function of the available chemical energy: the salt concentration here. The results can replicate similar processes in haptic biological muscles sensing their fatigue state.

Human and animal muscles sense while working mechanical, thermal or chemical working conditions: they are haptic muscles. Most of the efforts trying to clarify this dual and simultaneous activity have been focused on the localization of the different physical sensors working in a muscle. Alternatively some researchers suspect that the actuating reaction, ATP hydrolysis promoting the bending movement of the myosin head, is the origin of some sensing signals sent back to the brain.

Our group has been working from the end of the past century on the sensing properties of the electrochemical reactions of conducting polymers, carbon nanotubes or graphenes. By similitude with the Le Chatelier and Nerst sensing principles for chemical or electrochemical equilibriums a new sensing principle has been formulated for reactions, in particular for reactions driving conformational movements of the macromolecular reactants (molecular chemical machines): the reaction energy adapts to the reaction energetic (thermal, chemical, mechanical, electrochemical, optical …) conditions. An alternative formu-lation may be the following: any change or perturbation of the reaction energetic conditions is detected (is sensed) by the energy consumed during the reaction. The energy consumed by any electrochemical reaction is the product of the consumed charge (Q) by the electrical potential (E). Thus, the sensing magnitude must be any (depending of the working conditions) of those magnitudes or any other related to them (current, consumed energy …).

Those principles were deduced from empirical results using artificial muscles constituted by conducting polymers getting sensing and tactile devices, which replicate haptic biological muscles. When they work moving always from the same initial to the same final positions (a constant initial oxidation state of the muscle material to a different constant final oxidation state) driven by a constant current the evolution during the actuation of both, the muscle potential and the consumed electrical energy follow a linear dependence of the trailed mass (mechanical sensor), or of the working temperature (thermal sensor) and a semilogarithmic dependence of the electrolyte concentration (chemical sensor). Both, sensing (muscle potential) and actuating (driving current) magnitudes are present at any time in the only two connecting wires, replicating brain-muscle two ways simultaneous sensing and actuating communication.

Here we present a different approach to this principle studying the influence of the electrolyte concentration (available chemi-cal energy) on the extension (on the reaction charge) of the polypyrrole oxidation/reduction reactions when the material was studied by consecutive potential cycles between the same potential limits and at the same scan rate (constant electrical conditions) in different concentrations (different chemical energy) of NaCl aqueous solutions. Under those conditions the polypyrrole oxidation/reduction charge follows a double logarithmic dependence of the electrolyte concentration. The experi-mental results were supported by theoretical descriptions. Translated to biological processes those results could describe the brain consciousness of the muscle’s fatigue by depletion of ATP and oxygen concentration after a long working time. In addition these reactive sensing properties inspire the development of different electrochemical devices (artificial muscles, smart membranes, electrochromic devices) based on conducting polymers and other electroactive materials, which sense by themselves the ambient chemical conditions while working: dual sensing-actuators.

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Pairing Anodic Processes with Cathodic H2O2 Generation for Environmental Remediation Processes.Inmaculada Moraleda.

Inmaculada Moraleda1, José Fernando Pérez1, Javier Llanos1, C. Sáez1, P. Cañizares1, M. A. Rodrigo1

1 Chemical Engineering Department, University of Castilla-La Mancha, Edificio Enrique Costa Novella. Av. Camilo José Cela nº 12, 13071 Ciudad Real, Spain.

Electrochemical technologies present potential applicability to remediate a wide variety of environmental issues. Particularly, coupling or pairing the anodic and the cathodic processes in such a way that both reactions contribute to the global objective is an interesting form of optimizing the investment and operating cost of electrochemical reactors [1].

Different anodic processes such as direct or mediated generation of oxidants, photo-assisted TiO2 oxidation or Fe/Al electro-coagulation are of interest for wastewater treatment. In the counter electrode, the cathodic reduction of oxygen can generate hydrogen peroxide. This compound is of great interest due to its environmental compatibility. In this work, two examples of coupled environmental remediation processes which involve cathodic production of H2O2 are under study.

The hydrogen peroxide can be activated by means of Fe salts to yield high-oxidizing species, such as the hydroxyl radical (OH ) (Eq. 1) whereas a boron-doped diamond can simultaneously produce OH radicals by water splitting (Eq. 2):

H2O2 + Fe2+ OH• + Fe3+ + OH- (Eq. 1)

M + H2O – 1e- M (OH•) + H+ (Eq. 2)

The peracetic acid (PAA) is increasingly used in the industry, such as disinfectant or for the removal of organic pollutants. In the present work, its synthesis is improved by the in-situ generation hydrogen peroxide (Eq. 3) from acetic acid solution with boron-doped diamond anode. Both processes, the cathodic production of hydrogen peroxide and the anodic oxidation of acetic acid, are combined to increase PAA production [2].

CH3COOH + H2O2 CH3COOOH + H2O (Eq. 3)

The main innovation under study in the present work is the optimization of two key aspects of the reactor: aeration and cell potential. The air is supplied by means of a Venturi-based jet aerator to eliminate the need for a compressor [3]. Also, the cell potential is minimized by reducing the interelectrode gap in a novel flow-through microfluidic reactor.

References: [1] E. Brillas, I. Sirés, P.L.s. Cabot, Use of Both Anode and Cathode Reactions in Wastewater Treatment, in: C. Comninellis, G. Chen (Eds.) Electrochemistry for the Environment, Springer New York, New York, NY, 2010, pp. 515-552.[2] I. Moraleda, J. Llanos, C. Sáez, M.A. Rodrigo, P. Cañizares, Integration of anodic and cathodic processes for the synergistic electrochemical production of peracetic acid, Electrochemistry Communications 73 (2016) 1-4.[3] J.F. Pérez, J. Llanos, C. Sáez, C. López, P. Cañizares, M.A. Rodrigo, Electrochemical jet-cell for the in-situ generation of hydrogen peroxide, Electrochemistry Communications 71 (2016) 65-68.

Acknowledgements: Financial support from the Spanish Ministry of Economy, Industry and Competitiveness and European Union through project CTM2016-76197-R (AEI/FEDER, UE) is gratefully acknowledged.

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Self-powered electrochromic biosensor for glu-cose determination.M. Aller Pellitero.

M. Aller Pellitero1, A. Guimerà1,2, M. Kitsara1, C. Rubio3, B. Lakard3, M. Doche3, J. Hihnn, R. Villa1,2, and F.J. del Campo1

1 Instituto de Microelectrónica de Barcelona, IMB-CNM (CSIC), Spain.2 CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Spain.3 Institute UTINAM, France.

Self-powered (bio)sensors are devices that generate their own energy, either from the surroundings of from the sample itself, to provide an analytical response. Here we show that a galvanic cell consisting of an electrochromic display and an electroche-mical biosensor is sufficient to fabricate a self-powered analytical device that provides a direct visual analytical readout, thus avoiding the need for silicon-based electronics that would significantly increase both cost and complexity of the integration processes. We have connected an electrodeposited Prussian blue layer on an ITO electrode (cathode), to a screen-printed carbon electrode modified with a glucose biosensor (anode) [1]. A lateral flow membrane was used to enable the flowing of solutions between electrodes. These two electrodes were arranged so the cathode acts as a progress bar giving quantitative results of the glucose concentration (Figure 1a). A correlation between the colour distance consumed of the cathode with the amount of glucose flowing through the system can be observed (Figure 1b).

Figure 1. (a) Photo of the self-powered electrochromic device. (b) Captures of the display for different glucose concentrations and plot of the distance consumed of Prussian blue against the glucose concentration.

Using the correct layout of the components, the path of the current can be used to gradually consume the display thus obtaining information of the amount of charge flowing through it. This represents a step forward in the field of biosensing, extending also the application areas of electrochromic materials.

References: 1. Pellitero, M.A., Guimerà, A., Kitsara, M., Villa, R., Rubio, C., Lakard, B., Doche, M.L., Hihn, J.Y., del Campo, F.J., Chem. Sci., 8 (2017), 1995-2002.

Acknowledgements: This work was partly funded by the Spanish Ministry of Economy through the DADDi2 project (TEC2013-48506).


pH-Dependent Capacitance Switching in Microporous Hetero-Carbons: New Materials from Carbonized Polymers of Intrinsic Microporosity.Naiara Hernández.

Naiara Hernández 1*, Jesus Iniesta1, Vicente Montiel Leguey1, Robert Armstrong2, Stuart H. Taylor2, Elena Madrid3, Yuanyang Rong3, Rémi Castaing3, Richard Malpass-Evans4, Mariolino Carta4, Neil B. McKeown4, and Frank Marken3

1 Departamento de Química física e Instituto Universitario de Electroquímica, Universidad de Alicante, Apartado 99, 03080 Alicante, Spain.2 School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK.3 Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.4 School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh, Scotland EH9 3JJ, UK.

Pyrolysis of polymer precursors provides versatile access to both non-porous and porous electrode materials [1]. Only recently has the carbonization of a polymer of intrinsic microporosity (PIM) been reported [2] to give interesting heterocarbon materials. At this study we have carried out the vacuum carbonization at 700ºC of a nitrogen-containing polymer of intrinsic microporosi-ty (PIM-EA.TBH2); this polymer was converted into a microporous heterocarbon (cPIM). The surface area for both materials before and after the carbonization was measured by nitrogen adsorption technique resulting an area of 846 and 425 m2 g-1, respectively. After the carbonization the material results to keep the polymer backbone and the nitrogen functionalities which we suggest to be associated with pH-dependent properties.

A cPIM ink was prepared for the electrode preparation with the purpose to carry out an electrochemical characterization. After prolonged immersion in HClO4 solution the material exhibits a super-capacitor behaviour (with typically 50 F·g-1), the time-de-pendent increase in capacitance was associated with the slow hydration and ingress of HClO4 into the micropores. The same study was carried out employing H2SO4 and H3PO4 and resulted to be less effective in terms of capacitance increase. Once hydrated, the cPIM material exhibits pH-dependent capacitance “switching” over a wide pH range and analytical applications as “capacitive” pH sensor are proposed.

References: 1. Analytical methodologies using carbon substrates developed by pyrolysis: Benavidez, TE ; Martinez-Duarte, R; Garcia, CD ANALYTICAL METHODS .Volume: 8 Issue: 21 Pages: 4163-4176 DOI: 10.1039/c6ay00293e Published: 20162. Intrinsically Microporous Polymer Retains Porosity in Vacuum Thermolysis to Electroactive Heterocarbon: Rong, YY; He, DP; Sanchez-Fernandez, A; Evans, C; Edler, KJ ; Malpass-Evans, R; Carta, M; McKeown, NB; Clarke, TJ ; Taylor, SH; Wain, AJ; Mitchels, JM; Marken, F. LANGMUIR Volume: 31 Issue: 44 Pages: 12300-12306 DOI: 10.1021/acs.langmuir.5b02654 Published: NOV 10 2015

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Copper underpotential deposition on gold single crystal surfaces using a deep eutectic solvent.Paula Sebastián.

Paula Sebastián1, Elvira Gómez2, Víctor Climent1, J.M. Feliu1

1 Institute of Electrochemistry, University of Alicante, Apdo, 99, 03080 Alicante, Spain.2 Grup d’Electrodeposició de Capes Primes i Nanoestructures (GE-CPN). Universitat de Barcelona 08028 Barcelona. España.

Ionic liquids (ILs) have become very popular during the last decade due to their benefits like a wide electrochemical window, enough conductivity or relative good thermal stability. These particular properties explain why ionic liquid are, nowadays, so attractive for many applications. In particular, ionic liquids have been extensively used for metal electrodeposition. Many metals, metal oxides or even alloys have been successfully deposited using different ionic liquids[1]. However, most of these works use poly-orientated substrates, introducing a non-controlled variable (the surface) and thus leading difficulties in the interpretation of the results. So, in order to get better insight in the mechanism that governs metal electrodeposition in ionic liquids, single crystal surfaces were used in this work.

In the present communication copper electrodeposition on Au(h k l) was investigated using a DES (deep eutectic solvent) based on the mix between choline chloride and urea (1:2). Compared with the traditional RTILs (room temperature ionic liquids), DES are introduced as the friendly and green alternative. However, the information related with the interface Metal| DES is still scarce. Because of that, the interface Au(h k l)| DES was deeply analyzed previous to study copper electrodeposition on gold electrodes. The cyclic voltammograms showed characteristic and sharp features demonstrating the surface sensitivity of the process. Similar behavior for an ionic liquid was only reported by us, but using a RTIL instead, specifically the [Emmim][-Tf2N][2]. The influence of the species of the DES in the voltammetric response was evident. Afterwards, copper electrodeposi-tion on Au(h k l) was investigated, finding that the previous steps involves the deposition of a few copper submonolayers before reaching the nucleation and growth mechanism.

Figure 1: Blank cyclic voltammetry of Au(111) in A) [Emmim][Tf2N], B) 1ChCl:2urea. C) Cu UPD on Au(111) in 1ChCl:2urea.

References: 1. Zhang, Q., et al. ChemPhysChem, 2016. 17(3): p. 335-351.2. Sebastián, P., et al. Electrochemistry Communications, 2016. 62: p. 44-47.

0.5 1.0 1.5 2.0 2.5 3.0

-15

-10

-5

0

5

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E vs Cc/Cc+ / V

Au(111) | [Emmim][Tf2N]

50 mV/s

A

-0.5 0.0 0.5

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10

20

30 B

50 mV/s

j / μ

A c

m-2

Au(111) | 1ChCl:2urea

j / μ

A c

m-2

E vs Ag|AgCl / V

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E vs Ag|AgCl / V

Cu UPD on Au(111) in 1ChCl:2urea

5 mV/s

j / μ

A c

m-2

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Precise positioning control for PpyDBS selfsensing actuators. Johanna Schumacher.

Johanna Schumacher1,2, Toribio F. Otero2, Victor H. Pascual2

1 Arquimea Ingeniería S.L.U., Leganés, Madrid, Spain.2 Laboratory of Electrochemistry Intelligent Materials and Devices. Technical University of Cartagena. ETSII. Campus Alfonso XIII. 30203. Cartagena. Spain.

Self-sensing actuators based on conducting polymers are faradaic electrochemical motors. The angular position of any bending faradaic motor is controlled by the charge consumed by the driving electrochemical reactions of the electroactive component (conducting polymer) following in average a linear function. However, PPyDBS self-sensing actuators show dynamic hysteresis effects, which cause deviations from the desired position.

We present here the investigation and analysis of those dynamic hysteresis effects of polypyrrole-dodezylbenzenesulfonate (PpyDBS) self-sensing actuators submitted to current waves at different frequencies. A frequency dependent model is derived from the empirical data, implemented in a control loop and verified by a theoretical description. Actuator performances, with and without theoretical adjust, are compared showing more precise positioning control when the rate dependent model is integrated in the control loop.

Keywords: dual sensing-actuators, electroactive polymer, hysteresis, position control.

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Electro-bioremediation Scale-up Process of Pesticide Polluted Soil.Silvia Barba.

S. Barba1*, R. López-Vizcaíno2, C. Sáez3, J. Villaseñor1, P. Cañizares3, V. Navarro2, M.A. Rodrigo3

1 Department of Chemical Engineering, Instituto de Tecnologías Química y Medioambiental, University of Castilla-La Mancha, Campus Universitario s/n, Ciudad Real, Spain.2 Geoenvironmental Group, Civil Engineering School, University of Castilla-La Mancha, Avda. Camilo José Cela s/n, Ciudad Real, Spain.3 Department of Chemical Engineering, Facultad de Ciencias y Tecnologías Químicas, University of Castilla-La Mancha, Campus Universitario s/n, Ciudad Real, Spain.

Electro-bioremediation technology is based on the application of two different processes for the removal of pollutants in soils: electrokinetic and biological remediation. This novel technology has been proven efficient for the treatment of soils polluted with pesticides in bench scale [1].

The aim of this work is to show the results of the application of electro-remediation of soil which was polluted with two different pesticides: 2,4-dichlorophenoxyacetic acid (2,4-D) and oxyfluorfen as model of polar and nonpolar pesticide respecti-vely. An important novelty point of this work is the scale studied. The treatment has been developed in a prototype scale which is very similar to a real application (32 m3) [2]. The electrodic configuration selected was a fence assisted electrochemically composed on 3 anodes/ 3 cathodes alternates in a hexagonal distribution. The electric potential gradient applied was 1 V cm-1 during 1 month. The biological barrier placed in the soil was a microbial consortium adapted for 2,4-D and oxyfluorfen degradation. This microbial consortium was obtained from an activated sludge and supported during a week, before their addition in the soil, with a concentration of 300 ppm of glucose, 70 ppm of 2,4-D and 70 ppm of oxyfluorfen as carbon source in Bushnell-Hash broth, a culture media adequate to pesticide-degrading microbial consortium. Then, the microorganisms were introduced in the soil though the central well mixing them with sand. Results show that electrophoresis and electroosmo-tic favour the transport of the microorganisms through the soil and permit the movement of the pollutants between the electrodes improving the contact with microorganisms. Results are compared to those obtained in absence of biological permeable reactive barrier in order to clarify the main mechanisms involved in the removal of pollutants [3].

References:1. Barba, S., et al., Effect of the polarity reversal frequency in the electrokinetic-biological reme-diation of oxyfluorfen polluted soil. Chemosphere, 2017. 177: p. 120-127.2. López-Vizcaíno, R., et al., Scale-up on electrokinetic remediation: Engineering and technolog-ical parameters. Journal of Hazardous Materials, 2016. 315: p. 135-143.3. López-Vizcaíno, R., et al., Scale-up of the electrokinetic fence technology for the removal of pesticides. Part I: Some notes about the transport of inorganic species. Chemosphere, 2017. 166: p. 540-548.

Acknowledgements:Financial support from the Spanish Ministry of Economy, Industry and Competitiveness and European Union through project CTM2016-76197-R (AEI/FEDER, UE) is gratefully acknowledged.

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Thursday 6th July

Inmunosensores amperométricos para la determinación rápida y sencilla de biomarcadores proteicos de relevancia en cáncer.Eva Vargas.

Rebeca M. Torrente-Rodríguez, Víctor Ruiz-Valdepeñas Montiel, Susana Campuzano, María Pedrero, Francisco Javier Manuel de Villena, Eva Vargas, Rodrigo Barderas, José M. Pingarrón

Departamentos de Química Analítica y Bioquímica y Biología Molecular I, Facultad de CC. Químicas, Universidad Complutense de Madrid, Madrid, 28040, Spain.

En esta comunicación se presentan nuevas plataformas de inmunosensado para la determinación rápida, sensible y fiable de biomarcadores proteicos de relevancia reciente clínica en diagnóstico y pronóstico de cáncer: el receptor 4 del factor de crecimiento de fibroblastos (FGFR4) y la endoglina (CD105 o EDG) [1, 2]. Estudios recientes demuestran alteraciones en los niveles de FGFR4 en varios tipos de tumores y una sobrexpresión de esta proteína en tumores localizados en próstata, mama, páncreas, glándula pituitaria, hígado y sistema reproductor femenino [3, 4]. También se ha descrito la existencia de una estrecha relación entre la hiperexpresión de la glicoproteína CD105 en las células endoteliales angiogénicas de los tejidos tumorales y el proceso de metástasis, encontrándose niveles elevados de endoglina en sueros de pacientes con cáncer, que se correlacionan con la metástasis tumoral [5].

El fundamento de las plataformas inmunosensoras que se presentarán está basado en el empleo de formatos de ensayo tipo sándwich en los que se lleva a cabo la inmovilización covalente del anticuerpo específico sobre micro-partículas magné-ticas modificadas con grupos carboxílicos previamente activados para la captura selectiva de la proteína diana, el marcaje enzimático con un anticuerpo secundario marcado con HRP, y la posterior detección amperométrica sobre electrodos serigrafiados de carbono (SPCE) empleando el sistema HQ/H2O2/HRP. Ambos immunosensores presentan características analíticas y operacionales muy atractivas, con bajos límites de detección (48.2 pg mL-1 y 2.8 fg mL-1, respectivamente) y reducidos tiempos de ensayo (15 y 30 min, respectivamente) para la determinación amperométrica de FGFR4 y CD105, respectivamente. Cabe destacar además que ambos immunosensores se basan en ensayos de una única etapa, lo que les hace especialmente apropiados para su aplicación en la práctica clínica. Ambas plataformas han demostrado aplicabilidad satisfactoria en el análisis de muestras biológicas complejas, tras una simple dilución de las mismas. Así, se han determinado los contenidos endógenos de FGFR4 en diferentes lisados de células cancerígenas, requiriendo tan sólo 2.5 µg de lisado, y de CD105 en muestras de suero humano, comparando estadísticamente los resultados obtenidos con los proporcionados por los correspondientes kits ELISA comerciales. Estas sencillas plataformas de inmunosensado, de formato desechable y acoplables a transductores electroquímicos de bolsillo, se presentan como dispositivos analíticos con características idóneas para su integración en formatos portátiles y de multiplexado. Así, estos desarrollos pueden servir como base para la implementación de dispositivos POC para el diagnóstico y pronóstico de cáncer en la rutina hospitalaria a través de la determinación in situ de estos u otros biomarcadores de naturaleza proteica relacionados con enfermedades de relevancia.

References: 1. R.M. Torrente-Rodríguez et al. PLoS ONE. 2016, (Accepted).2. R.M. Torrente-Rodríguez et al. Journal of Pharmaceutical and Biomedical Analysis. 2016, 129, 288.3. Z.R. Qian et al. Clin. Endocrinol. Metab. 2004, 89 (4), 1904.4. A. Peláez-García et al. PLoS ONE. 2013, 8(5): e63695. doi:10.1371/journal.pone.0063695.5. S. Zeng et al. Sensors. 2012, 14, 13471.

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The effect of surface coverage by adsorbed species on the kinetics of oxygen reduction reaction at oxide free copper in neutral medium.Nisrine Benzbiria.

Nisrine Benzbiria1,2*, Siham Echihi1, Wafaa Qafsaoui1, Mustapha Zertoubi2, Mohamed Azzi2 Rodrigo3

1 Laboratoire Eau et Environnement (LEE), Faculté des Sciences d’El Jadida, Route Ben Maachou, 24000, El Jadida, Maroc.2 Laboratoire Interface Matériaux et Environnement (LIME), Faculté des Sciences Aïn Chock, B.P.5366 Maârif, Casablanca, Maroc.

The oxygen reduction reaction (orr) is one of the most important electrocatalytic reactions due to its role in metal corrosion and electrochemical energy conversion systems, particularly in fuel cells [1]. Many reaction mechanisms have been proposed to describe orr in aqueous electrolytes. The reduction pathway is influenced by the nature of the catalysts but also by the surface state and structure. Some experiments have shown that O2 reduction rate is lower on oxide-covered surfaces than on bare metal electrodes [2]. The oxygen level and moreover, the presence of adsorbing species are among the factors considera-bly influencing the orr kinetics. In contrast to the extensive studies of Pt surfaces, there are relatively few studies of the effects of anion adsorption on the kinetics of orr on copper [3].

In the present study, the kinetic parameters of oxygen reduction, such as reaction order, kinetic current, Tafel slope and the number of electron exchanged were determined, on oxide free copper using the rotating disc electrode. It has been found that in sulfate sodium solution the kinetics of the orr on copper are found to be the first order reaction with respect to dissolved O2. Thus, using Koutecky-Levich equation, the current plateau indicated a 4 electron transfer mechanism.

The effect of adsorbed species was highlighted using cyclic voltammetry. Indeed, it was observed that the rate of orr in the positive going sweep was higher than in the negative going sweep. Accordingly, the hysteresis observed for the orr is positio-ned in the potential region where (bi)sulfate adsorption occurs. Therefore, we suggest that the potentiodynamic curves recorded during the positive going sweep represent the orr on a partially covered surface with (bi)sulfate anions while during negative going sweep, the orr begins on a surface which is almost fully covered by the adsorbed anions. The major effect of the adsorbed species on the orr kinetics and reaction pathway on copper surface is the blocking of active copper sites for the adsorption of O2 molecules [4].

References:1. N. Travitsky, T. Ripenbein, D. Golodnitsky, Y. Rosenberg, L. Burshtein, E. Peled, J. Power Sources, 161 (2006) 782–789.2. D. Sepa, M. Vojnovici, A. Damjanovic, ElectrochimicaActa,Vol. IS (1970) 1355-1366.3. Y. Lu, H. Xu, J. Wang, X. Kong, ElectrochimicaActa, 54 (2009) 3972–3978.4. T. Jiang, G.M. Brisard, ElectrochimicaActa, 52 (2007) 4487–4496.


Dependency of the mechanical properties of PPy/DBS films with the oxidation state and the electrogeneration parameters.Victor H. Pascual.

Victor H. Pascual1, Toribio F. Otero1, Johanna Schumacher2, Joaquin Arias-Pardilla1, Laura Valero3

1 Laboratory of Electrochemistry and Intelligent Materials, Technical University of Cartagena, ETSII, Campus Alfonso XIII, 30203, Cartagena, Spain. 2 Arquimea Ingeniería, Margarita Salas 10, 28919, Leganés, Spain. 3 Engineering School, Universidad Autónoma del Estado de México, Toluca 50000, Mexico.

Some biological organs sense by themselves working conditions: a permanent feedback communication exists between them and the brain. [1]. For the last three decades a plethora of new electrochemical devices constituted by electrochemical molecular motors has been developed. They replicate biological functions working driven by chemical and electrochemical reactions. In particular, conducting polymers have been studied due to their potentiality to work as a dual sensing actuators devices resembling the way in which haptic muscles do in animals and humans: they mimic functional reactions and molecular motors occurring inside muscle cells [2], [3]. The electrochemical reactions drive the exchange of ions and solvent with the surroundings for charge and osmotic balance and the conformational movements of the reacting chains (molecu-lar motors) generating/destroying the required free volume to lodge/expel, respectively, counterions and solvent [4]. Polypyrrole/dodecylbenzene sulfonate (PPy/DBS) polymers blends have proven the ability of the reaction, through the consumed energy, to sense energetic changes in the surrounding medium, such as thermal or chemical energy [5]–[7]. Now, in this work, the mechanical properties of the constitutive PPy/DBS material have been assessed as a function of the oxidation state of the polymeric film and the synthesis electrochemical conditions, revelling thus a way to, by means of the control of the electrogeneration parameters obtain materials with tailor-made mechanical properties.

References: [1] T. F. Otero and J. G. Martinez, “Physical and chemical awareness from sensing polymeric artificial muscles. Experiments and modeling,” Prog. Polym. Sci., vol. 44, pp. 62–78, May 2015.[2] T. F. Otero, “Biomimetic Conducting Polymers: Synthesis, Materials, Properties, Functions, and Devices,” Polym. Rev., vol. 53, no. 3, pp. 311–351, Jul. 2013.[3] T. F. Otero and J. G. Martinez, “Biomimetic intracellular matrix (ICM) materials, properties and functions. Full integration of actuators and sensors,” J. Mater. Chem. B, vol. 1, no. 1, pp. 26–38, 2013.[4] T. F. Otero, J. G. Martinez, and J. Arias-Pardilla, “Biomimetic electrochemistry from conducting polymers. A review Artificial muscles, smart membranes, smart drug delivery and computer/neuron interfaces,” Electrochimica Acta, vol. 84, pp. 112–128, Dec. 2012.[5] N. Aydemir et al., “Electrolyte and solvent effects in PPy/DBS linear actuators,” Sens. Actuators B-Chem., vol. 216, pp. 24–32, Sep. 2015.[6] S. Maw, E. Smela, K. Yoshida, and R. B. Stein, “Effects of monomer and electrolyte concentrations on actuation of PPy(DBS) bilayers,” Synth. Met., vol. 155, no. 1, pp. 18–26, Oct. 2005.[7] L. Valero Conzuelo, J. Arias-Pardilla, J. V. Cauich-Rodriguez, M. Afra Smit, and T. Fernandez Otero, “Sensing and Tactile Artificial Muscles from Reactive Materials,” Sensors, vol. 10, no. 4, pp. 2638–2674, Apr. 2010.

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Concentration Strategies – An upgrade for electrochemical degradation technologies. Martin Muñoz.

J. Llanos, A. Raschitor, M. Muñoz, P. Cañizares, M. A. Rodrigo

Chemical Engineering Department, University of Castilla-La Mancha, Edificio Enrique Costa Novella. Av. Camilo José Cela nº 12, 13071 Ciudad Real, Spain.

In the last decades, the development of electrochemical technologies for the removal of different kind of pollutants from wastewater, especially organics, reached important advances. Given the importance of this matter, many studies have been focused on the improvement and optimization of different electrochemical processes such as electroxidation [1] or electrocoa-gulation [2].

Despite these important efforts, several aspects should be still researched. When treating wastewater with low concentration of organic pollutants, the mass transfer limitations appear and reduces the maximum removal rate as well as the current efficiency of the process. This case is usual for many persistent and emerging contaminants being well-known that the higher the concentration of the pollutant, the higher is the current efficiency of the electrochemical treatment process [3].

The present work aims to revise different approaches that have been investigated to increase the efficiency of electrochemical degradation technologies when low concentrated wastes are treated. Moreover, it brings novel results about the conjunction of degradation and concentration technologies with the end of enhancing the rate and the global efficiency of the treatment process in question.

During the combination of concentration and degradation technologies, it is important to consider if the target pollutant is non-ionic or ionic. For non-ionic pollutants, electrocoagulation can be a suitable choice to concentrate the contaminant before its degradation. First, it is necessary to trap the pollutant into the solids and, subsequently, the concentration step can be performed just by the acidification of the solution to re-dissolve the solids in a reduced volume. This concept has been evalua-ted using oxyfluorfen as model of non-ionic pollutant and iron as anode. It was observed that it is possible to concentrate oxyfluorfen by electrocoagulation, increasing its depletion rate.

For ionic matter, it is possible to use electrodialysis to perform the simultaneous removal and degradation of the pollutant by a proper placement of the ion exchange membranes. In this case, it was observed that it is possible to concentrate and to deplete simultaneously 2,4-D, increasing significantly the rate and the efficiency of the process, thus lowering the environmen-tal impact and the cost of the treatment. These two examples of assisted concentration could open a new way of improving the electrochemical treatment technologies of wastewater containing low concentration of organic pollutants.

References:1. Rubí-Juárez, H., et al.,. Applied Catalysis B: Environmental, 2016. 188: p. 305-312.2. Zodi, S., et al., Desalination, 2010. 261(1–2): p. 186-190.3. M. Panizza, G. Cerisola, Direct and mediated anodic oxidation of organic pollutants, Chemical Reviews, 109 (2009) 6541-6569. Acknowledgements:Financial support from the Spanish Ministry of Economy, Industry and Competitiveness and European Union through project CTM2016-76197-R (AEI/FEDER, UE) is gratefully acknowledged.

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Thursday 6th July

Surface isothermal nucleic-acid based amplification strategies in integrated electrochemical biosensors.Noemí De los Santos Álvarez.

N. De los Santos Álvarez, S. Barreda-García, A. Brasa-Marqués, R. Lorenzo-Gómez, R. Miranda-Castro, A.J. Miranda-Ordieres, M.J. Lobo-Castañón

Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Av. Julián Clavería 8, 33006, Oviedo.

Short oligonucleotide sequences are become stablished as excellent receptors for the construction of biosensors. The exquisite selectivity of hybridization reaction is the basis for the development of genosensors while an induced conformatio-nal change is the origin of the recognition ability of aptamers for their ligand. This way, the panel of potential analytes to be detected is virtually unlimited.

In the clinical field, biomarker quantitation demands the detection of extremely low levels of circulating nucleic acids or secreted proteins in a highly complex matrix. To boost sensitivity amplification strategies are required. Nucleic acid-based receptors are especially well suited because they can be easily manipulated using molecular biology tools, so they are amenable to strategies precluded to other receptors (e.g. antibodies).

Among the molecular amplification strategies, polymerase chain reaction (PCR) is the technique of choice for most target (genosensor) or signal (aptasensor) amplifications. However, the need for dedicated equipment capable of thermal cycling prevents the development of true low-cost biosensors. Here, we propose isothermal amplification strategies as helicase-de-pendent amplification (HDA), recombinase polymerase amplification (RPA) or rolling circle amplification (RCA) carried out on the electrode surface to integrate all steps in a small and inexpensive device.

Acknowledgements:This work has been supported by Spanish government (CTQ2015-63567-R), and co-financed by FEDER funds.

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Análisis por Espectroscopía Electroquímica de Impedancias (EIS) de un Proceso de Adsorción con una Etapa Química Previa. Aplicación a la Adsorción de Adenina sobre Electrodos Au(111) en Función del pH del Medio.Francisco Prieto.

Francisco Prieto, Manuela Rueda, Julia Álvarez-Malmagro

Departamento de Química Física. Facultad de Química. Universidad de Sevilla. c/ Profesor García González 1. 41012. Sevilla.

Resulta frecuente en procesos faradaicos sobre electrodos la existencia de reacciones químicas acopladas a la etapa de transfe-rencia electrónica propiamente dicha. Por ejemplo, si la especie electroactiva no está presente originalmente en la disolución, sino que tiene que formarse en una etapa química previa, se habla de mecanismo CE. La presencia de estas etapas químicas de naturaleza homogénea altera el perfil de concentraciones de las distintas especies participantes, y por tanto las ecuaciones de flujo de las especies implicadas en la transferencia electrónica. De igual manera que en los procesos faradaicos, en el caso de la adsorción de especies orgánicas sobre electrodos es frecuente encontrar la presencia de etapas químicas de protonación o de desprotonación acopladas al proceso de adsorción

En la presente comunicación se presentan las expresiones deducidas para la Impedancia Electroquímica para un proceso de adsorción con una etapa química precedente. El modelo desarrollado se ha basado en el modelo cinético de adsorción original-mente desarrollado por Frumkin y Melik-Gaykazian [1] y posteriormente modificado para evitar realizar ninguna suposición a priori sobre la isoterma de adsorción [2,3]. Se han obtenido las ecuaciones de la impedancia electroquímica en función de la frecuencia, y se ha analizado la influencia que los distintos valores de los parámetros cinéticos y termodinámicos de la etapa química previa tienen sobre los espectros de impedancia, encontrándose dos casos límite, a altas y a bajas frecuencias, en los que la dependencia de la impedancia con la frecuencia es idéntica a la correspondiente a un proceso de adsorción sin etapa química previa.

El modelo desarrollado se aplica a la adsorción de adenina sobre electrodos de oro Au(111) desde disoluciones a pH 1, 7 y 11, en los que la adenina en disolución se encuentra protonada, neutra y desprotonada, respectivamente. Los resultados previos de espectro-electroquímica IR han mostrado que solo la adenina neutra y desprotonada se adsorben químicamente, por lo que en la adsorción a pH 1 el proceso de adsorción debe incluir una etapa previa de desprotonación.[4]

Referencias:1. Frumkin, A. & Melik-Gaykazyan, V. Determination of the Kinetics of Adsorption of Organic Substances by a.-c. Measurements of the Capacity and the Conductivity at the Boundary: Electrode-Solution. Dokl. Acad. Nauk 77, 855–858 (1951).2. Kerner, Z. & Pajkossy, T. On the origin of capacitance dispersion of rough electrodes. Electrochim. Acta 46, 207–211 (2000).3. SluytersRehbach, M and Sluyters, J. H. in Comprehensive Treatise of Electrochemistry, vol 9 (eds. Yeager, E., Bockris, J. O., Conway, B. E. & Sarangapani, S.) 177–292 (Plenum Press, 1984).4. Rueda, M., Prieto, F., Rodes, A. & Delgado, J. M. In situ infrared study of adenine adsorption on gold electrodes in acid media. Electrochim. Acta 82, 534–542 (2012).


Janus electrochemistry: double functionalization in a unique step.Aránzazu Heras.

David Ibáñez1, Elvira Gómez2, Elisa Vallés2, Álvaro Colina1, Aránzazu Heras1

1 Department of Chemistry, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.2 Grup d’Electrodeposició de Capes Primes i Nanoestructures (GE-CPN). Dep. Ciència de Materials i Química Física and Institut de Nanociència i Nanotecnologia (IN2UB). Universitat de Barcelona, 08028 Barcelona, Spain.

Over the last few decades, Janus structures are attracting intense interest because of their outstanding and adaptable chemical and physical properties. Although different synthesis routes have been used for the fabrication of Janus architec-tures, in the case of Janus membranes the use of wet routes has been limited to the capillary effect. It involves the gradual penetration of the solution through the membrane [1], avoiding the double functionalization of the two faces of the membranes in one step. In this work, we propose a new methodology to overtake the capillary limitation and to get a double electrochemical functionalization of free-standing carbon nanotube (FS-SWCNT) films in only one step. This new electrochemical method will be the base for a new route to fabricate Janus structures by simultaneous electrochemical functionalization of two-faces in a single step.

In order to validate this new strategy and to obtain Janus structures in one electrochemical step, different systems have been studied, as for example reversible redox couples and conducting polymers. As a proof of concept, FS-SWCNT films have been functionalized with two different conducting polymers, in particular with polyaniline (PANI) and poly(3-hexyl-thiophene) (P3HT), in a unique electrochemical experiment (Figure 1). According to the obtained results, this new electro-chemical methodology will open up new gates for the design and functionalization of Janus materials.

Figure 1. (a) UV-Vis spectra recorded in normal configuration during the double functionalization in one electrochemical step. (b) Electrochemical characterization of PANI (blue line) and P3HT (orange line) faces.

References: 1. H. Yang, J. Hou, V. Chen, Z. Xu, Angew. Chemie Int. Ed. 2016, 55, 13398–13407.

Acknowledgements:Financial support from Ministerio de Economía y Competitividad (CTQ2014-61914-EXP, CTQ2014-55583-R, TEC2014-51940-C2-2R, CTQ2015-71955-REDT) and Junta de Castilla y León (BU033-U16) is gratefully acknowledged.

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Preparación y caracterización de cátodos de difusión de aire modificados con quinonas para el tratamiento electroquímico de contaminantes.Carlota Ridruejo.

Carlota Ridruejo1, Idoia Siso1, Garbiñe Álvarez2, Francisco Alcaide2, Enric Brillas1, Ignasi Sirés1

1 Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona.2 Unidad de Materiales para la Energía,Área de Almacenamiento de Energía, IK4-CIDETEC, Paseo Miramón 196, 20009 San Sebastián.

El peróxido de hidrógeno es un importante agente oxidante utilizado a nivel industrial para numerosas aplicaciones. Actual-mente, la producción mundial de H2O2 se estima en 5 millones de toneladas métricas.1 La obtención de H2O2 por métodos electroquímicos se puede llevar a cabo a través de la reducción bielectrónica de O2, ya sea disolviendo aire en el electrolito o bien inyectándolo en un electrodo de difusión. Entre los materiales electródicos más utilizados para este propósito se encuen-tran los basados en carbono, ya que tienen buena estabilidad, conductividad y resistencia. En los últimos tiempos, la atención se ha dirigido hacia los carbones nanoestructurados, tales como el grafeno y los nanotubos de carbono. Estos últimos presen-tan unas propiedades texturales que favorecen la reacción de reducción del O2.

En este trabajo, se han sintetizado varios electrocatalizadores por vía hidrotérmica utilizando nanotubos de carbono funcionali-zados. Se ha realizado la caracterización electroquímica de estos materiales mediante técnicas potenciodinámicas con el objetivo de evaluar su capacidad para generar H2O2, y se han preparado cátodos de difusión con el fin de llevar a cabo la generación potenciostática y galvanostática de H2O2 en un sistema de tres y dos electrodos, respectivamente. En estos ensayos se emplearon diferentes electrolitos, tales como Na2SO4 y NaCl, con la finalidad de averiguar el efecto del cloro activo electro-generado por oxidación anódica del anión Cl-.

Los mejores electrocatalizadores se han modificado, a su vez, mediante diferentes rutas de síntesis química/electroquímica. De este modo, se pretende introducir compuestos quinónicos para mejorar la reducción electrocatalítica del O2 en medio ácido, ya que éste es el medio óptimo para llevar a cabo los tratamientos de aguas basados en la reacción de Fenton. La elección de estos compuestos obedece a su uso en la producción industrial de H2O2. En último término se han realizado tratamientos electroquímicos de disoluciones acuosas de un fármaco en celda no dividida equipada con un cátodo de difusión de aire modificado.

Referencias:1. Q. Li, C. Batchelor-McAuley, N.S. Lawrence, R.S. Hartshorne, C.J.V. Jones, R.G. Compton, J. Solid State Electrochem. 18 (2014) 1215-1221. Agradecimientos:Los autores agradecen la financiación dentro del proyecto CTQ2016-78616-R (AEI/FEDER, UE) y de la Red E3TECH (CTQ2015-71650-RDT, MINECO, España), y la beca FPI concedida a C. Ridruejo (MINECO, España).


Study of the pH dependency at neutral values for HER and HOR on Pt(hkl) electrodes.Valentín Briega-Martos.

Valentín Briega-Martos, Ricardo Martínez-Hincapié, Paula Sebastián-Pascual, Enrique Herrero, Juan M. Feliu

Instituto de Electroquímica, Universidad de Alicante, Apdo. 99, E-03080 Alicante, Spain.

Hydrogen evolution and oxidation (HER/HOR) are key reactions in electrocatalysis, because of their technological importance in fields such as fuel cells or energy storage, and also because they are simple electrochemical reactions that are suitable to be studied by using models, which can be compared with experiments on well-oriented surfaces of single crystal electrodes.

The properties of the interphase between the electrode surface and the solution have a strong influence on the rate of electro-catalytic reactions. The reaction rate of the HER is higher in acidic than in alkaline media, and it has been proposed that the difference is due to the influence of the interfacial electric field on the energetic barrier for the interfacial water restructuration [1]. In this sense, an exhaustive study of HER/HOR at more neutral pH values could shed light on role of H+ availability for these reactions.

It has been shown that NaF/HClO4 mixtures can provide enough buffering capacity avoiding any specific anion adsorption [2]. In this work, HER and HOR are studied on Pt(hkl) surfaces at a wide pH range. The polarization curves for the HER show two waves, a first one limited by the concentration of H+, and a second one corresponding to the hydrogen evolution from H2O (Fig. 1A). The onset potential for the latter depends strongly on the pH, being more positive for more neutral pH values. In addition, the kinetic current densities at a given potential value for the proton limited reaction are higher as the pH is increased within the investigated potential range. Studies using the Pt(hkl) basal planes indicate that in these pH values both HER and HOR are structure sensitive (Fig 2B). The possible influence of the previous homogeneous acid-base equilibrium is currently investigated.

Fig. 1. Polarization curves for the HER on Pt(111); 50 mV s-1; 2500 rpm; inset: calculated kinetic current densities (A). Polariza-tion curves for the HER on the Pt(hkl) basal planes; pH = 5.4 (B)

References:1. I. Ledezma-Yanez, D. Z. Wallace, P. Sebastián-Pascual, V. Climent, J. M. Feliu, M. T. M. Koper, Nature Energy 2 (2017) 17031-170372. R. Martínez-Hincapié, P. Sebastián-Pascual, V. Climent, J. M. Feliu, Electrochem. Commun. 58 (2015) 62-64

Acknowledgements:Support from MINECO (Spain) through projects CTQ2016-76221-P and Generalitat Valenciana through project PROMETEOII/2014/013 is greatly acknowledged. VBM thankfully acknowledges to MINECO the award of a pre-doctoral grant (BES-2014-068176)

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Plataformas electrocatalíticas nanoestructuradas basadas en la química de las sales de diazonio.Félix Pariente.

M. Revenga-Parra1,2,3, A. Amor1, E. Lorenzo1,2,3, F. Pariente1,3

1 Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, 28049 Madrid (Spain).2 IMDEA-Nanoscience. Faraday 9, Campus Cantoblanco-UAM, 28049 Madrid (Spain).3 Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid (Spain).

Recientemente, se ha demostrado el enorme potencial del empleo de sales de diazonio preparadas in situ para modificar la superficie de un buen número de electrodos convencionales de manera sencilla, rápida y eficiente, con el objetivo de obtener películas electroactivas con diferentes finalidades, entre ellas la de catalizar la electroxidación de diferentes analitos de interés sobre la superficie del electrodo. Las sales de arendiazonio se preparan de manera rápida y sencilla en una sola etapa a partir de una amplia gama de aminas aromáticas primarias, muchas de las cuales están comercialmente disponibles, pudiendo proporcionar una gran variedad de grupos funcionales. Tras la generación de la sal de arendiazonio, se produce un radical arilo mediante un proceso de electrorreduccion que, tras la pérdida de una molécula de nitrógeno, se enlaza de manera covalente a la superficie del electrodo. De este modo, el electroinjerto es un proceso de inmovilización que da como resultado superficies electródicas modificadas con respuestas reproducibles y propiedades nuevas o mejoradas.

Basándonos en la química del diazonio, en el presente trabajo se han preparado las sales de diazonio de algunos compues-tos que presentan en su estructura grupos funcionales electroactivos y que pueden usarse por tanto como mediadores redox en el diseño de sensores y biosensores. En concreto, se han utilizado moléculas que han mostrado ser muy buenos mediadores redox en la oxidación de NADH, cofactor de un gran número de enzimas involucradas en reacciones de oxidación-reducción. Las moléculas de mediador diazotizadas se han electroinjertado directamente en la superficie de electrodos serigrafiados de oro previamente modificados con distintas nanoestructuras de carbono (grafeno, nanodiamante y nanopuntos de carbono) con el fin de mejorar las propiedades del dispositivo final. En la presente contribución se ha estudiado cómo afecta la presencia de los distintos nanomateriales al proceso de electroinjerto de la sal de diazonio y a las propiedades electroquímicas de la película electroinjertada sobre la superficie electródica. Se han evaluado las posibles ventajas que la presencia de estas películas electroactivas ejercen sobre la respuesta final del electrodo modificado y por tanto en las propiedades electrocatalíticas del mismo.

Referencias:1. Daniel Bélanger and Jean Pinson. Electrografting: a powerful method for surface modification. Chem. Soc. Rev., (2011), 40, 3995–4048.2. Revenga-Parra, M.; Gomez-Anquela, C.; Garcia-Mendiola, T.; Gonzalez, E.; Pariente, F.; Lorenzo, E. Grafted Azure A modified electrodes as disposable β-nicotinamide adenine dinucleotide sensor. Anal. Chim. Acta (2012), 747, 84-91.


CO2 electroreduction to formate: Gas-phase System for Avoiding Liquid Catholyte.Andrés Del Castillo.

A. Del Castillo1, M. Alvarez-Guerra1, J. Solla-Gullón2, L. García-Cruz2, V. Montiel2, A. Irabien1

1 Universidad de Cantabria, Dep. Ingenierías Química y Biomolecular, ETSIIT Avda. Los Castros s/n, Santander 39005 España. Email: [email protected] Instituto de Electroquímica, Universidad de Alicante Ap. 99, Alicante 03080 España.

CO2 electroreduction is consider an interesting option for the utilization of captured CO2. Coupling CO2 electroreduction with renewable energies, such as solar or wind power, could allow to store the excess of intermittent renewable energy and balance the electricity consumption. Formate is considered a suitable fuel for fuel cells and it has been proposed as a renewable hydrogen carrier. Therefore, this product is an interesting chemical product that can be obtained from CO2 in an electrochemi-cal process. Sn is the most common metal electrocatalyst for electroreduction of CO2 to formate. It is usually deposited over porous supports to enhance the electrocatalytic surface and increase the productivity of the reactor. In CO2 electroreduction it is very important to obtain a high formate concentration in the output stream since the purification step consumes a lot of energy and it is a critical step for the industrial implementation of this process [1]. Previous research using Sn gas diffusion electrodes (GDEs)[2] achieve high formate concentration in the output stream. Despite the results, it is necessary to increase the concentration, still far from e.g. 85% wt.[3], the most common concentration in the market. Consequently, this communi-cation is focused on the design of new system for the electrochemical reduction of CO2 to formate that could avoid or reduce the use of liquid catholyte and increase the concentration of product formate obtained.

The core of the experimental system is a zero-gap electrochemical reactor, coupled to a vapour delivery module, in such a way that a CO2 stream is humidified and directly feed in gaseous phase to the reactor. Output stream is cooled to condense the water with the product and they are collected in a tank. The reactor operates in continuous mode and without recirculation. It was possible to adjust the gas temperature and the ratio between gas flow and H2O in the input stream. Sn carbon suppor-ted nanoparticles deposited on a Nafion 117 membrane were use both as cathode with a tinned steel mesh as current collector. Nafion 117 is used as cell divider and support for the electrocatalytic material. Preliminary tests with this reactor configuration revealed that the ratio between CO2 flow and H2O is a critical variable for the correct operation of the reactor and in this sense further research is required to optimise the performance and further increase the concentration of formate obtained.

References:1. A. Dominguez-Ramos, B. Singh, X. Zhang, E.G. Hertwich, A. Irabien. Global warming footprint of the electrochemical reduction of carbon dioxide to formate. Journal of Cleaner Production, 2015, 104: 148-1552. A. Del Castillo, M. Alvarez-Guerra, J. Solla-Gullón, A. Sáez, V. Montiel, A. Irabien. Sn nanoparticles on gas diffusion electrodes: Synthesis, characterization and use for continuous CO2 electroreduction to formate. J. of CO2 Utilization, 2017, 18: 222–2283. M. Pérez-Fortes and E. Tzimas. Techno-economic and environmental evaluation of carbon dioxide utilisation for fuel production. Synthesis of methanol and formic acid; EUR 27629 EN; doi: 10.2790/981669

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Electrodos de oro modificados por “grafting” como plataformas inmunosensoras para la determinación del péptido YY.Sara Guerrero.

S. Guerrero, M.L. Agüí, P. Yáñez-Sedeño, J.M. Pingarrón

Dpto. Química Analítica, Facultad de Ciencias Químicas, UCM, 28040 Madrid.

El péptido YY (PYY) es un anorexígeno producido en el intestino y secretado al torrente sanguíneo tras la ingesta de alimen-tos, con un potente efecto de saciedad. Es considerado como un posible agente terapéutico para el control del apetito y la prevención de enfermedades relacionadas con la obesidad, como la diabetes de tipo 2 y enfermedades cardiovasculares [1]. En este trabajo se describe el desarrollo de un inmunosensor electroquímico basado en una configuración tipo sándwich para la determinación del PYY sobre electrodos serigrafiados de oro cuyo esquema de preparación y funcionamiento se muestra en la Figura 1. Para la inmovilización del anticuerpo de captura se ha aplicado un procedimiento de “electrograf-ting” basado en el empleo del ácido 4-aminobenzoico en medio orgánico, estrategia de funcionalización de superficies de oro no muy extendida, a pesar de presentar numerosas ventajas frente a las monocapas autoensambladas (SAMs).

La optimización de las etapas involucradas en su preparación ha permitido obtener respuestas para el 1-naftol, mediante voltamperometría diferencial de impulsos, con una relación de señal específica/inespecífica 10:1, una buena reproducibilidad entre medidas (RSD = 4.9%, n=6) que pone de manifiesto la bondad del proceso de fabricación seguido, así como un alto grado de selectividad frente a otras especies que pueden acompañar el PYY en muestras clínicas, no observando interferencia apreciable al nivel de concentración ensayado (0.1µg/mL).

Figura 1: Preparación del inmunosensor para PYY

Referencias: [1]: M.E. Londoño-Lemos, Rev. Colomb. Cienc. Quím. Farm., 41 (2012) 217-261


Modificación superficial de Pt(111) con adátomos de Ni. Efecto sobre la oxidación de CO.Francisco J. Sarabia.

Francisco J. Sarabia, Víctor Climent, Juan M. Feliu

Departamento de Química-Física, Instituto de Electroquímica, Universidad de Alicante, Apdo. 99,. 03080, Alicante.

La necesidad de obtener nuevas fuentes de energía limpia y económica, como solución al problema de la contaminación, ha impulsado el diseño y desarrollo de nuevos materiales que permitan realizar transformaciones electroquímicas eficientes. El uso de superficies bimetálicas permite mejorar la catálisis a través de cambios en la geometría de enlace, en la distribución de sitios activos, en las propiedades electrónicas del sustrato, o mediante un mecanismo bifuncional. Por ejemplo, las aleaciones Pt/Ni y Pt/Sn se han propuesto como unos de los mejores catalizadores para la reducción de oxígeno y la oxidación de CO, respecti-vamente [1-2]. En este trabajo se estudia el depósito de adátomos de Ni sobre Pt(111), y se demuestra la formación de Ni-(OH) adsorbido mediante desplazamiento de carga con CO. Además, se ha ensayado la respuesta del electrodo de Pt(111) modifica-do con Ni para la oxidación de monóxido de carbono.

Referencias:1. V. R. Stamenkovic, B. Fowler, B.S. Mun, GF Wang, P. N. Ross, C. A. Lucas, N. M. Markovic, Science, 2007, 315, 493-497.2. Wang, K; Gasteiger, HA; Markovic, NM; Ross, PN; Electrochimica acta, 1996, 41, 2587 – 2593.

Figura 1. a) Blanco correspondiente al electrodo Pt(111) en ausencia de Ni. b) CV medido en presencia de sulfato de níquel. 0,1 M NaF/HClO4 (pH=4,5). 50mV/s

Figura 2: Oxidación de una monocapa de CO sobre el electrodo Pt(111) a) sin Ni b) tras depositar Ni. 0,1 M NaF/HClO4 (pH=4,5). 20mV/s

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Estudio de la formación de películas de derivados silano sobre sustratos de oro.Guadalupe Sánchez-Obrero.

Irene Humanes, Juan José Peinado, José Manuel Sevilla, Guadalupe Sánchez-Obrero, Rafael Madueño, Manuel Blázquez, Teresa Pineda

Departamento Química Física y Termodinámica Aplicada, Instituto de Química Fina y Nanoquímica, Universidad de Córdoba, Ed. Marie Curie, 2ª Planta, Campus de Rabanales, 14014 Córdoba, España.

Los silanos se consideran compuestos químicos de baja toxicidad y se utilizan como recubrimientos en materiales en implan-tología debido a sus propiedades como promotores de adhesión. Aunque la silanización directa de aleaciones metálicas tales como acero y latón no es un concepto nuevo, el uso de estos recubrimientos en materiales biocompatibles ha desper-tado un gran interés en los últimos años.[1,2]

Las propiedades de adhesión de estos recubrimientos dependen fuertemente de su estructura final y es muy importante, por tanto, establecer metodologías apropiadas para la optimización de estas propiedades. El control de la composición de estas películas, así como en la organización de los componentes es de gran importancia a la hora de diseñar los procesos de recubrimiento para las diferentes aplicaciones.

En este trabajo se presenta un estudio de la formación de películas de derivados silano haciendo énfasis en la caracteriza-ción de los materiales obtenidos en cada paso del proceso. Para ello se preparan monocapas y bicapas empleando como monómeros los derivados 3-amino- y 3-mercapto-propil trimetoxisilano (APTS y MPTS). Estas capas sirven como base para realizar capas de diferente espesor mediante revestimiento con polímeros formados in situ.

Para la caracterización de las estructuras obtenidas en cada paso del proceso se han utilizado técnicas electroquímicas como la cronoamperometría, la voltamperometría cíclica y la espectroscopía de impedancias electroquímica. Además, para la evaluación de las películas se han medido los ángulos de contacto del agua, pudiéndose establecer el grado de hidrofilici-dad de las mismas. Por otra parte, se ha abordado el estudio de la composición de las capas moleculares mediante espectroscopía XPS.

Referencias: (1) Matinlinna, J. P.; Tsoi, J. K.-H.; de Vries, J.; Busscher, H. J. Characterization of novel silane coatings on titanium implant surfaces. Clinical Oral Implants Research 2013, 24, 688-697.(2) Cheng, H. C. K.; Tsoi, J. K. H.; Zwahlen, R. A.; Matinlinna, J. P. Effects of silica-coating and a zirconate coupling agent on shear bond strength of flowable resin-zirconia bonding. International Journal of Adhesion and Adhesives 2014, 50, 11-16.

Agradecimientos: Ministerio de Economía y Competitividad (MINECO) (Proyectos CTQ2014-60227-R and CTQ-2015-71955-REDT Red de Excelencia Sensores y Biosensores Electroquimicos), Junta de Andalucía (P10-FQM-6408) y Universidad de Córdoba.


Development of electrochemical sensors based on metal nanoparticles obtained from spent screen-printed electrodes.Beatriz Gómez-Monedero.

Beatriz Gómez-Monedero, María-Isabel González-Sánchez, Jerónimo Agrisuelas, Edelmira Valero

Department of Physical Chemistry, School of Industrial Engineers, University of Castilla-La Mancha, Campus Universitario S/N, 02071 Albacete, Spain.

Screen printing is a widely used technology to produce low-cost disposable electrodes, which have allowed the determination of numerous substances for some decades now[1,2]. The vast consumption of these devices carries an inherent production of solid wastes that contain precious metals such as platinum, silver, gold, etc, which are highly polluting but also valuable materials. Therefore, it is necessary to investigate strategies to properly process spent screen-printed electrodes (SPEs), in order to meet future demand and to protect resources.

The main purpose of this work is to develop a procedure to selectively recover precious metals from screen-printed electrodes (SPEs), to be subsequently used in the preparation of SPEs modified with metal nanoparticles (NPs). Modification of SPEs using NPs is a quite recent approach[3,4] which allows the manufacture of electrochemical sensors with interesting properties, for example as H2O2 sensors[5]. Therefore, by using different leaching solutions, noble metal-containing inks used to manufacture working, counter and reference electrodes of spent SPEs have been selectively recovered. Figure 1 shows spent screen-printed platinum electrodes (SPPtEs) after different acidic treatments. The recovered metals have been electrodeposited onto new SPEs in the form of NPs, and tested in sensing applications such as H2O2 quantification.

Figure 1. Selective recovery of noble metal inks of a spent SPPtE: A) Spent SPPtE, B) After the removal of the plastic cover, C) After the recovery of the Ag ink, D) After the recovery of the Pt ink.

Funding source: Spanish Ministry of Economy and Competitiveness (MINECO, http://www.mineco.gob.es/portal/site/mineco/i-di), Projects No. BFU2013-44095-P and BFU2016-75609-P (cofounded with FEDER funds, EU). B. G-M. is a post-doctoral research fellow of the Youth Employment Initiative (JCCM, Spain, cofounded with ESF funds, EU).

References:1. O.D. Renedo, M.A. Alonso-Lomillo, M.J.A. Martinez. Talanta 73 (2007) 202–219.2. M.I. González-Sánchez, E. Valero, R.G. Compton. Sens. Actuators B: Chem. 236 (2016) 1–7.3. S. Sanllorente-Méndez, O. Domínguez-Renedo, M.J. Arcos-Martínez. Electroanalysis 21 (2009) 635–639.4. I.M. Apetrei, C. Apetrei. Sensors 16 (2016) 422.5. J. Lamas-Ardisana, O.A. Loaiza, L. Añorga, E. Jubete, M. Borghei, V. Ruiz, E. Ochoteco, G. Cabañero, H.J. Grande. Biosens. Bioelectron. 56 (2014) 345–351.

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Enrichment procedure as the key to get highly efficient Microbial Fuel Cells.Sara Mateo.

S. Mateo, F.J. Fernández, P. Cañizares and M.A. Rodrigo

University of Castilla-La Mancha, Faculty of Chemical Sciences & Technologies, Chemical Engineering Department, Avenida Camilo José Cela, 12. 13071 Ciudad Real, Spain.

Microbial fuel cell has attracted a rising interest due to its possibility to become the new green energy. It is a bioelectroche-mical device that exploits the capability of bacteria called electrogenic bacteria to use an electrode as the final electron acceptor of its metabolic reactions, in which biodegradable organic matter is used as substrate, and are able to establish an appreciable current [1]. It makes this technology very interesting to be installed in WasteWater Treatment Plant (WWTP) instead of the conventional aerobic reactor which requires a high electrical supply and even, to provide energy in our daily life. How powerful and how efficient can be the MFCs depends on many factors and parameters. Among them, the enrich-ment procedure is a crucial factor because can drastically affect the performance. There are many studies that propose inoculation processes but entail unnecessary cost [2,3]. In this context, the aim of this work is to explore simple and inexpensive procedures to grow potential electrogenic bacteria. For this purspose, four identical MFCs were started up under different enrichment procedures: recirculating 100 % v/v of aerobic sludge during the first day, a liquor of 50% of the volume of aerobic sludge and the remaining 50% of synthetic wastewater, a solution of 10% of the volume of aerobic sludge and the remaining 90% of synthetic wastewater and finally, 100% v/v of anaerobic sludge. These MFCs were air-breathing cathode consists of a 0.346 cm3 anodic compartment, which hosts the bacteria and the anodic electrode (0.87 cm2 of carbon felt), separated from the cathodic chamber by a Nafion proton exchange membrane. The cathodic chamber is simplified to a cathodic electrode exposed to the atmosphere. It was made of carbon paper (C2 Freudenberg) with a layer of 0.5 mg Pt cm-2. Anode, membrane and cathode were placed as closed as possible to reduce the internal resistance and anode and cathode were connected externally by a 120 Ω resistance. The MFCs were connected hydraulically to an auxiliary tank of 115 cm3 which contains the liquor recirculated continuously in the system. Results showed that after 4 days, the MFC inoculated with aerobic sludge under starving condition started to show an increasing exerted current from 0.61 A m-2 up to 4.02 A m-2 at the 10th day, moment in which the steady state was achieved so the selection process was concluded. Polarization and power curves carried out at the steady state provided a maximum power density of 1.5 W m-2 and a maximum current density of 11.26 A m-2. Nevertheless, the other strategies may not favoured the development of an electrogenic culture as the exerted current densities were negligible.

References: 1. R.A. Rozendal, H.V.M. Hamelers, K. Rabaey, J. Keller, C.J.N. Buisman, Towards practical implementation of bioelectrochemical wastewater treatment, Trends Biotechnol. 26 (2008) 450–459. 2. S. Wang, L. Huang, L. Gan, X. Quan, N. Li, G. Chen, L. Lu, D. Xing, F. Yang, Combined effects of enrichment procedure and non-fermentable or fermentable co-substrate on performance and bacterial community for pentachlorophenol degradation in microbial fuel cells, Bioresour. Technol. 120 (2012) 120–126. 3. S. Venkata Mohan, G. Mohanakrishna, B.P. Reddy, R. Saravanan, P.N. Sarma, Bioelectricity generation from chemical wastewater treatment in mediatorless (anode) microbial fuel cell (MFC) using selectively enriched hydrogen producing mixed culture under acidophilic micro-environment, Biochem. Eng. J. 39 (2008) 121–130.


Electrocoagulación simple o acoplada como alternativa en el sector del aceite de oliva.Nelly Flores.

Nelly Flores, Enric Brillas, José A. Garrido, Rosa M. Rodríguez, Francesc Centellas, Pere L. Cabot, Ignasi Sirés

Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona.

El proceso de producción de aceite de oliva resulta muy contaminante desde el punto de vista de la gran cantidad de agua residual generada (OOMWW) y de la ausencia de tratamientos adecua-dos en el caso de la pequeña empresa, convirtiéndose en un riesgo ambiental importante, en particular en el cuenca del Mediterráneo [1]. El objetivo de este trabajo es investigar la eficacia de varios trata-mientos electroquímicos para disminuir el contenido total de materia orgánica de una muestra real de OOMWW colectada en una pequeña cooperativa catalana. Se ha aplicado el proceso de electrocoa-gulación (EC) convencio-nal, así como un tratamiento acoplado haciendo uso de un post-tratamiento mediante procesos electroquímicos de oxidación avanzada (EAOPs) tales como el proceso electro-Fenton (EF) y fotooelectro-Fenton (FEF). La EC se llevó a cabo en una celda no dividida empleando 150 mL de disoluciones de OOMWW, a 25 ˚C. Se utilizó un ánodo y un cátodo de 10 cm2, ambos de hierro, con una separación de 1 cm y aplicando 30-300 mA durante 45 min. Para el estudio de los tratamientos acoplados, la disolución final se centrifugó y el sobrenadante se trató mediante EF o FEF, con un ánodo de BDD y un cátodo de C-PTFE de difusión de aire de 3 cm2, aplicando 30 o 75 mA.

El tiempo óptimo para la EC fue de 20 min, consiguiéndose la máxima eliminación de carbono orgánico total (TOC) y turbidez posible gracias a la buena coagulación de los coloides y compuestos iónicos presentes en la matriz real. Se obtuvo una disminu-ción de TOC del 34% y 51% trabajando a 30 y 300 mA, respectivamente. Además, se generó una concentración de hierro disuelto entre 0.1-1.0 mM, suficiente para llevar a cabo EAOPs basados en la reacción de Fenton. El uso de EF y FEF como post-tratamientos permitió llegar a eliminaciones de TOC elevados, de hasta 85-87% a 75 mA a los 480 min de electrólisis, a pesar del pH ligeramente alcalino que presentaban las disoluciones electrocoaguladas. No se observaron diferencias significati-vas al utilizar EF o FEF, lo que indica la ausencia de compuestos fotosensibles. Cabe destacar que los procesos acoplados condu-jeron a resultados mejores que los tratamientos EF y FEF individuales, lo que pone de relieve el interés del acoplamiento propuesto en este estudio.

Referencias:S. Dermeche, M. Nadour, C. Larroche, F. Moulti-Mati, P. Michaud, Olive mill wastes: Biochemical characterizations and valorization strategies, Process Biochem. 48 (2013) 1532–1552.

Agradecimientos: Los autores agradecen la financiación dentro del proyecto CTQ2016-78616-R (AEI/FEDER, UE) y de la Red E3TECH (CTQ2015-71650-RDT, MINECO, España), y la beca doctoral concedida por Senescyt (Ecuador) a N. Flores.

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Catalizadores de Ni soportados sobre materiales grafénicos para las reacciones de reducción de oxígeno y de evolución de hidrógeno.Elena Pastor.

C. Montero, L.M. Rivera, J. Flórez, G. García, E. Pastor

Instituto Universitario de Materiales y Nanotecnología, Dpto. Química, Universidad de La Laguna, 38200, La Laguna, Tenerife, España.

Las celdas de combustible de membrana de intercambio protónico (PEMFC) son dispositivos capaces de convertir directa-mente la energía química contenida en un combustible, como el hidrógeno, en energía eléctrica; mientras que el proceso inverso, en el que se genera hidrógeno y oxígeno a partir de agua, puede realizarse en electrolizadores tipo PEM. En ambos casos, el Pt y sus aleaciones son los catalizadores más eficientes y estables en medio ácido, pero debido a su elevado coste, se siguen realizando numerosos esfuerzos para reducir o incluso eliminar su presencia en dichos dispositivos. En este sentido, el desarrollo de membranas alcalinas ha hecho posible el uso de catalizadores basados en metales no nobles, con nanopartículas dispersadas sobre soportes carbonosos, que presentan una superficie elevada con baja carga metálica. El grafeno aparece como un soporte prometedor debido a sus excepcionales propiedades, por lo que se han desarrollado diferentes métodos de síntesis que permiten modular las propiedades de estos materiales para mejorar las interacciones entre el soporte y las partículas catalíticas, por ejemplo, funcionalizándolos con heteroátomos como N y S [1]. Por otro lado, los metales no nobles más baratos, como el Ni y sus aleaciones, también se han utilizado como catalizadores en medios alcalinos con buena resistencia a la corrosión [2].

En este trabajo se han dispersado nanopartículas de Ni sobre diferentes soportes grafénicos, estudiando su comportamiento electroquímico para la reducción de oxígeno y la evolución del hidrógeno (ORR y HER, respectivamente). El óxido de grafeno (GO) se sintetizó mediante el método de Hummers modificado y se funcionalizó usando tiourea como reactivo. El Ni se soportó por reducción de la sal de Ni precursora con un poliol, seguida de un tratamiento térmico bajo atmósfera reductora, o por un procedimiento hidrotermal, obteniendo partículas metálicas soportadas sobre óxido de grafeno reducido (rGO) y rGO funcio-nalizado con N y S. Todos los materiales se caracterizaron fisico-químicamente y electroquímicamente.

Se analizó la actividad catalítica para el ORR y HER de los materiales grafénicos y de los catalizadores sintetizados. Se observó que los primeros también eran activos para la ORR y que se modificaba la respuesta con su funcionalización. Además, la incorporación de Ni mejoró la actividad tanto para la ORR como para la HER, dependiendo a su vez del tratamiento realizado. Se demostró, además, que se alcanzaron diferentes grados de reducción del GO y que la presencia de átomos de S induce la formación de partículas de NiS sobre la superficie del grafeno, influyendo ambos factores en las densidades de corriente y en los potenciales desarrollados.

References: 1. Soo LT, Loh KS, Mohamad AB, Daud WRW, Wong WY. “An overview of the electrochemical performance of modified graphene used as an electrocatalyst and as a catalyst support in fuel cells”. Appl Catal A Gen; 497, 2015, 198-210.2. Safizadeh F, Ghali E, Houlachi G. “Electrocatalysis developments for hydrogen evolution reaction in alkaline solutions - A Review”. Int J Hydrogen Energy; 40(1), 2015, 256-274.

Agradecimientos: Este trabajo ha sido financiado por el Ministerio de Economía y Competitividad (MINECO) en el proyecto ENE2014-52158-C2-2R (cofinanciado por FEDER). GG, LMR y CM agrade-cen al programa Viera y Clavijo (ACIISI & ULL), a la ACIISI y al MINECO, respectivamente, por el apoyo financiero.


Actividad de electrodos de PtAuSn soportados sobre carburos metálicos para la electrooxidación de etanol. Mª Carmen Arévalo.

Gonzalo García, Olmedo Guillén-Villafuerte, María Carmen Arévalo, José Luis Rodríguez, Elena Pastor

Instituto Universitario de Materiales y Nanotecnología, Dpto. Química, Universidad de La Laguna, 38200, La Laguna, Tenerife, España.

Uno de los principales retos de las células de combustible de etanol directo (DEFC) es mejorar la eficiencia de la reacción de oxidación del etanol (EOR) en el compartimento anódico. El desa-rrollo de catalizadores ideales que puedan oxidar completa-mente el etanol en CO2 sigue siendo obje-to de numerosos estudios, ya que hasta el momento requiere el uso de electrodos con elevado coste basados en platino. Por otra parte, estos catalizadores están generalmente soportados sobre materia-les carbonosos, que puede corroerse bajo ciertas condiciones, dando lugar al desprendimiento y la aglomeración de las nanopartí-culas de catalizador [1]. Por ello, la búsqueda y el diseño racional de materiales de bajo costo que no contengan metales nobles, con alta eficiencia y durabilidad, tendrá un impacto significativo en la implementación de esta tecnología. En este contexto, los carburos de metales de transición aparecen como potenciales electrocatalizadores y/o soportes alternativos. El gran interés de estos materiales reside en que poseen una estructura electrónica similar, cerca del nivel de Fermi, a la de los metales del grupo del Pt [2].

En este estudio se utilizan carburos metálicos del grupo 6 (Mo2C y W2C) como soportes inno-vadores para las nanopartículas de platino y aleaciones de platino (PtAuSn). El objetivo es compren-der mejor la interacción soporte/catalizador y establecer su influencia en la eficiencia de la EOR.

La composición química, así como las estructuras cristalográficas y características geométri-cas de los catalizadores, se han establecido mediante espectroscopía fotoelectrónica de rayos X (XPS), la difracción de rayos X (XRD) y la microscopía electróni-ca de transmisión (TEM). Se han utili-zado la voltamperometría cíclica y la cronoamperometría en ausencia y presencia de etanol, junto la electrooxidación de CO (“stripping”), para evaluar la tolerancia al CO, la superficie electroquímicamen-te activa (EASA) y el rendimiento de los catalizadores hacia el EOR. Para una mejor comprensión del mecanismo EOR y para determinar la eficiencia de conversión de CO2, se han realizado mediciones de espectrometría de masas diferencial electroquí-mica (DEMS) [3].

Los principales resultados indican una mayor tolerancia al CO y eficiencia de conversión de energía durante el EOR en cataliza-dores soportados en carburos metálicos en comparación con los soportados en materiales carbonosos.

Referencias:1. Vielstich W, Lamm A, Gaseiger HA. Handbook of Fuel Cells—Fundamentals, Technology and Applications. Handb Fuel Cells—Fundamentals, Technol Appl 2003;3:190.2. G. García, O. Guillén-Villafuerte, J.L. Rodriguez, M.C. Arévalo, E. Pastor, Int. J. Hydrogen Energy 41 (2016) 19664.3. Guillén-villafuerte O, García G, Arévalo MC, Rodríguez JL, Pastor E., Electrochem. Commun. 63 (2016) 48.

Agradecimientos: Este trabajo ha sido financiado por el Ministerio de Economía y Competitividad (MINECO) en el proyecto ENE2014-52158-C2-2R (cofinanciado por FEDER) y por el Séptimo Pro-grama Marco de la UE (Proyecto DECORE, NMP4-SL-2012-309741). GG agradece al programa Viera y Clavijo (ACIISI & ULL) por el apoyo financiero.

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4,4’-Dinitroestilbeno. Una síntesis electroquímica.Iluminada Gallardo.

Iluminada Gallardo, Belén Gómez-Aguilera, Manuel Ortigosa, Sergio Soler

Departamento de Química, Universidad Autónoma de Barcelona, 08193 Bellaterra.

4,4’-dinitroestibeno (DNSB) es conocido como un colorante textil de amplio uso [1] y más recientemente como interruptor molecular. [2] Se ha descrito, tanto, su síntesis química [3] a partir de 4-nitrotolueno como su síntesis electroquímica [4] a partir de 4-nitrotolueno y 4.4’-dinitrobibencilo (DNBB).

En este trabajo, se ha realizado un estudio de las condiciones de electrosíntesis del DNSB a partir del DNBB; para mejorar la conversión del DNBB y el rendimiento en DNSB. Se han mostrado como condiciones relevantes: la naturaleza del disolvente, la atmosfera utilizada y la concentración inicial del reactivo. Se han mostrado como irrelevantes, la naturaleza de la sal de fondo, la naturaleza del electrodo de trabajo y la utilización de potencial controlado o intensidad controlada. Es destacable que los rendimientos (en masa de producto separado) no son superiores pero igualan a los obtenidos en trabajos anteriores (rendimientos “in situ” determinados por Voltamperometria Cíclica (VC) o por GC).

En ningún caso se recupera DNBB y se obtienen como subproductos alcoholes y cetonas derivadas.

Referencias: 1. Song, D. H., Yoo, H. Y. & Kim, J. P. Synthesis of stilbene-based azo dyes and application for dichroic materials in poly(vinyl alcohol) polarizing films. Dye. Pigment. 75, 727–731 (2007).2. Yamauchi, K., Takashima, Y., Hashidzume, A., Yamaguchi, H. & Harada, A. Switching between supramolecular dimer and nonthreaded supramolecular self-assembly of stilbene amide-4,4’-cyclodextrin by photoirradiation. J. Am. Chem. Soc. 130, 5024–5025 (2008).3. Lu, J., Wang, Y.-L., Feng, Y. & Gu, L. No Title. Yingyang Huaxue 17, 651 (2000).4. Gallardo, I. et al. Electrochemical Synthesis of E-Dinitrostilbene from Nitroarenes. A Revision Study. Chem.ElectroChem (enviado)

Agradecimientos: Financial support from projects CTQ2012-30853 and CTQ2015-65439, as well as Spanish excellence network E3TECH funded by the Ministry of Economy and Competitiveness (MINECO) under project CTQ2015-71650-RDT is acknowledged. The PhD grant awarded to Sergio Soler (UAB) is acknowledged.


Origins of bistability and Na ion mobility difference in P2- and O3- Na2/3Fe2/3Mn1/3O2 cathode polymorphs.N. A. Katcho.

N. A. Katcho1, J. Carrasco1, D. Saurel1, E. Gonzalo1, M. Han1, F. Aguesse1, T. Rojo1,2

1 CIC Energigune, Albert Einstein 48, 01510 Vitoria-Gasteiz (Basque Country).2 Departamento Química Inorgánica, Universidad del País Vasco UPV / EHU, 48080, Bilbao (Basque Country).

Transition metal layered oxides are promising cathode materials for sodium-ion batteries. Phase transitions involving different stacking sequences of the oxide layers often plague the electrochemistry of these materials during cycling, which strongly impacts in their electrochemical performance. However, the underlying mechanisms of these processes remain elusive. Interes-tingly, P2- and O3-Na2/3Fe2/3Mn1/3O2 phases are the first transition metal layered oxide polymorphs that have been synthesized with exactly the same composition. This offers unprecedented access to the study of bistability in these systems as well as isolates the effect of local structure on Na ion mobility. Here, first-principles calculations and experiments are combined to unveil the physical origin of such bistability and identify important differences in Na ion diffusion between these two phases.

Figure 1. Left: Crystal structures of P2- and O3- Na2/3Fe2/3Mn1/3O2 polymorphs. Right: First-principles total energies as a function of the interlayer distance.

References: 1. N. A. Katcho, J. Carrasco, D. Saurel, E. Gonzalo, M. Han, F. Aguesse, T. Rojo, Adv. Energy. Mater. 2016, 7, 1601477.

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Figure 1. Determination of the pH at the Au/electrolyte interface as a function of applied potential during a lineal potential sweep in CO2-saturated MHCO3 solutions (M = Li, Na, K, Cs) in D2O. The pH was determined from the ratio between the integrated absorbance of the CO2 and HCO3- bands in ATR-SEIRA spectra

Figure 2. ATR-SEIRA spectra of a Ag electrode in N2 (bottom) and CO2 (top) in a 18/82 (mol/mol) EMIMBF4/wa-ter mixture at 1.5 V vs. a quasireference Pt electrode.


ATR-SEIRAS and DFT-based computational studies of CO2 electroreduction in different media.Angel Cuesta.

Onagie Ayemoba1, Marco Papasizza1, Xiaohui Yang1, Jun Cheng1,2 and Angel Cuesta1

1 Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, Aberdeen AB24 3UE, Scotland, UK.2 State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.

We report on a combined experimental and computational effort to study the electrocatalytic reduction of CO2 (CO2RR).

ATR-SEIRAS was used to determine the interfacial pH during the CO2RR (Figure 1). Our results confirm recently suggested cation-dependent buffering effect [1]. We have also used ATR-SEIRAS to detect intermediates during the CO2RR on Ag in ionic liquid/water mixtures (Figure 2), which has been claimed to occur at very low overpotentials [2]. In addition to the final product (CO), we have observed a band at 1316 cm-1, which corresponds to the symmetric stretching of a bridge-bonded adsorbed carboxylate. Possible candidates are adsorbed formate or the product of CO2 insertion in the imidazolium ion of the ionic liquid. Finally, we have adapted a method for the SHE [3] to calculate a computational Ag/AgCl reference electro-de. This is a first step to calculate a computational reference electrode in non-aqueous solvents, with which we will calcula-te the corresponding equilibrium potential for the CO2RR, and the test the validity of recent claims [2] of CO2 reduction at low overpotentials.

References: (1) Singh, M. R.; Kwon, Y.; Lum, Y.; Ager, J. W.; Bell, A. T. J. Am. Chem. Soc. 2016, 138 (39), 13006–13012.(2) Rosen, B. A.; Salehi-Khojin, A.; Thorson, M. R.; Zhu, W.; Whipple, D. T.; Kenis, P. J. A.; Masel, R. I. Science 2011, 334 (6056), 643–644.(3) Cheng, J.; Sprik, M. Phys. Chem. Chem. Phys. 2012, 14 (32), 11245–11267.


Thickness-properties synergy in organic–inorganic consolidated melting-gel coatings for protection of 304 Stainless Steel in NaCl solutions.Jadra Mosa.

J. Mosa1, M. Aparicio1, A. Jitianu2,3, G. Rodriguez2, K. Al-Marzoki4, M. Jitianu5, L. C. Klein4

1 Instituto de Cerámica y Vidrio, Consejo Superior de Investigaciones Científicas (CSIC), Kelsen 5, 28049 Madrid, Spain.2 Department of Chemistry, Lehman College, CUNY, Davis Hall, 250 Bedford Park Boulevard West Bronx, New York 10468 USA. 3 Ph.D. Program in Chemistry and Biochemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA.4 Department of Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, New Jersey 08854, USA.5 Department of Chemistry, William Paterson University, 300 Pompton Road, Wayne, New Jersey 07470, USA.

Homogeneous and crack-free methyl-substituted organic-inorganic hybrid glass coatings (thickness up to 10 µm) were deposi-ted on AISI 304 stainless steel. Different hybrid glasses obtained from consolidation of the diluted melting gels with various methyltriethoxysilane (MTES) / dimethyldiethoxysilane (DMDES) ratios were evaluated considering chemical structure, coating adhesion and corrosion protection.

The 70MTES / 30DMDES (molar %) melting-gel coating provided improved corrosion protection for this steel due to the synergy of different properties: a highly cross-linked inorganic structure, a coating plasticity based on the hybrid network, and a good adhesion to the substrate through hydroxyl groups. Electrochemical results show a good barrier film with a passive range of 500 mV, a low anodic current density (0.03 nA cm-2) and impedance values of 109.5 ohm cm2 after two months of immersion in 3.5 wt. % NaCl solution (1).

References:1. M. Aparicio, A. Jitianu, G. Rodriguez, K. Al-Marzoki, M. Jitianu, J. Mosa, L. C. Klein. “Thickness-properties synergy in organic–inorganic consolidated melting-gel coatings for protection of 304 stainless steel in NaCl solutions”. Surface & Coatings Technology 315 (2017) 426-435.

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Espectroelectroquímica de Fotoluminiscencia Aplicada al Estudio de Puntos Cuánticos de Grafeno.Álvaro Colina.

Joaquín Barrera1, David Ibáñez1, Aránzazu Heras1, Virginia Ruiz2, Álvaro Colina1.

1 Departamento de Química, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, España.2 IK4-CIDETEC, División de Materiales, Pº Miramón 196, E-20009 San Sebastián, España.

Los puntos cuánticos de grafeno (GQDs) están atrayendo gran atención debido a sus especiales propiedades ópticas y electrónicas. Dentro de la familia de los materiales basados en grafeno, los GQDs están siendo utilizados en aplicaciones muy prometedoras en campos muy diferentes. Su luminiscencia presenta gran interés debido a la posibilidad de ser utiliza-dos en medios biológicos, ya que en principio, presentan una alta biocompatibilidad. Sin embargo, tanto su comportamien-to electroquímico como óptico es todavía tema de debate, por lo que parece necesario utilizar herramientas que proporcio-nen información relativa a sus propiedades, sobre todo con medidas en los medios donde van a ser utilizados y en los que pueden suceder multitud de reacciones químicas. La espectroelectroquímica de fotoluminiscencia es una técnica muy prometedora para la caracterización de estos materiales [1], ya que proporciona información sobre el efecto de la transfe-rencia electrónica en el comportamiento luminiscente de este material. En el presente trabajo se ha realizado el estudio espectroelectroquímico de los GQDs en diferentes condiciones experimentales.

Figura 1. Evolución de los espectros de fotoluminiscencia de los GQDs durante un barrido de potencial.

Referencias:1. J. Barrera, D. Ibañez, A. Heras, V. Ruiz, A. Colina, J. Phys. Chem. Lett. 2017, 8, 531–537.

Agradecimientos:Este trabajo ha sido realizado gracias a la financiación del Ministerio de Economía y Competitividad (CTQ2014-61914-EXP, CTQ2014-55583-R, TEC2014-51940-C2-2R, CTQ2015-71955-REDT) y de la Junta de Castilla y León (BU033-U16)


Effect of doping on the outstanding electrochemical performance of Manganese-based sodium layered oxides for Na-ion batteries.Elena Gonzalo.

Elena Gonzalo,1* Nagore Ortiz-Vitoriano,1,2 Nicholas E. Drewett,1 Begoña Acebedo,1 Neeraj Sharma,3 Teófilo Rojo.1,4

1 CIC Energigune, Albert Einstein 48, 01510, Miñano, Spain.2 IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain.3 School of Chemistry, UNSW Australia, Sydney New South Wales 2052, Australia.4 Dept. Química Inorgánica, Facc. Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU) Barrio Sarriena s/n, 48940 Leioa - Bizkaia, Spain.

Sodium ion batteries have been in focus recently as good alternative to Li ion batteries for stationary applications. A considera-ble activity devoted to finding new cathode materials for those Na- ion batteries has exponentially increased in the recent years [1,2]. In particular, Na layered oxides are getting significant attention due to their excellent electrochemical properties, structu-ral simplicity and scalable synthesis method [3]

NaxMnO2 has been considered as one of the most versatile systems, although it shows some issues as the Jahn-Teller distortion effect due to the presence of Mn3+ (d4), which could cause loss of capacity and multiple step plateaus [4].

Different sodium layered oxides based on Mn as the main transition metal (TM) with NaxMn1-yM´yO2 as chemical formula, have been investigated by our group. The effect of both electrochemically active (Fe) and inactive (Mg, Ti) elements has been analyzed.

When M´= Fe different solid solutions of the P2- Na2/3Mn1-yFeyO2 (0.1<y<0.66) phases have been synthesized and their structu-ral and physicochemical characterizations have been carried out [5,6]. The electrochemical performance of the new materials has been improved and better cyclability achieved [7].

We will present not only the already described results but also those reported by our group regarding the positive effect that a small proportion of Mg[8] and Ti[9] can have on the electrochemical stability of the Na-Mn-O system and the newest electro-chemical results regarding other substituents [10].

References:1. V. Palomares, et al., Energy Environ. Sci. 2012, 5, 5884-5901.2. V. Palomares, et al., Energy Environ. Sci., 2013,6, 2312- 2337.3. M. H. Han, et al., Energy Environ. Sci. 2015, 8, 81-102.4. N. Ortiz-Vitoriano el al., Energy Environ. Sci. 2017, DOI 10.1039/C7EE00566K.5. E. Gonzalo, et al., J. Mater. Chem. A 2014, 2, 18523-18530.6. W. Dose et al., Chem. Mater. 2016, 28, 6342−6354.7. W. Dose et al., Advanced Funct. Mater. (submitted).8. J. Billaud et al., Energy Environ. Sci., 2014, 7, 1387–1391.9. M. H. Han, et al., Chem. Mater. 2016, 28, 106−116.10. Paper in preparation.

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Estudio de la corrosión del hierro con y sin inhibidor mediante EIS y LEIS con microcelda.Mercedes Sánchez.

C. López1, N. Casillas1, P. Herrasti2, M. Sánchez3

1 Departamento de Ingeniería Química, Universidad de Guadalajara Centro Universitario de Ciencias Exactas e Ingenierías (CUCEI)Blvd. Marcelino García Barragán #1451Guadalajara, Jalisco, México, CP. 44430.2 Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Física aplicada, Madrid. 3 Instituto de Ciencias de la Construcción “Eduardo Torroja” (IETcc-CSIC), C/ Serrano Galvache 4, 28033, Madrid.

En este trabajo hemos estudiado la corrosión del hierro en medio ácido (HCl 0.1M), en dos sistemas diferentes mediante impedancia electroquímica. El primero, un sistema de tres electrodos tradicional, con un área del electrodo de trabajo de 1 cm2 (EIS) y por otro lado empleando una microcelda electroquímica sobre un área de trabajo local de 0.0019 cm2 (LEIS). La idea fundamental del estudio es dilucidar y confirmar que las medidas con microcelda son comparables a las medidas realizadas en un sistema electroquímico tradicional. La microcelda electroquímica ha sido diseñada para trabajar en estanco o en flujo [1], por lo que es posible en este sistema analizar el efecto que el flujo tiene en la respuesta de impedancia electroquímica.

Otro aspecto que se ha considerado, es el efecto de un inhibidor (líquido iónico) sobre la corrosión del hierro, empleando también los dos sistemas electroquímicos mencionados previamente.

La respuesta del hierro en medio ácido en un sistema electroquímico tradicional presenta dos constantes de tiempo, una debida al proceso de transferencia de carga y otra de tipo difusivo, apareciendo incluso a tiempos largos un elemento inductivo, respuesta similar a la observada en la literatura [2]. En el caso del estudio en microcelda se observa el elemento inductivo desde tiempos de exposición cortos. En este caso la respuesta de impedancia parece estar controlada por un proceso de difusión en capa finita. La aplicación del flujo elimina tanto el proceso inductivo como el difusional en capa finita asociado a la acumulación de productos de corrosión sobre la superficie, dando lugar a una respuesta de impedancia similar a la observada con el sistema tradicional.

La incorporación del inhibidor (cloruro de 1-dodecil-3-metilimidazolio) a la disolución ácida en concentración 100 ppm, presenta en todos los casos una única constante de tiempo con valores de la resistencia a la transferencia de carga mucho más elevadas que sin inhibidor, corroborando el efecto inhibidor del líquido iónico. Además, este hecho se manifiesta por la ausencia del elemento inductivo en los diagramas de Nyquist.

Como conclusión podemos decir que el uso de una microcelda electroquímica para el estudio de corrosión, permite evaluar de forma precisa dicho proceso, siendo reproducible en diferentes puntos de la muestra, realizados mediante mapeo. La incorporación del flujo elimina los productos de corrosión sobre la superficie del metal y como consecuencia también el control difusivo. El inhibidor cloruro de 1-dodecil-3-metilimidazolio ha demostrado ser un efectivo inhibidor para el hierro en disolución ácida de HCl.

References:1. C. López, P. Herrasti, M. Sánchez, N. Casillas, “Design and characterization of an electrochemical microcell and its application in mass transport coefficient determination”, Electrochimica Acta, submitted (March 2017).2. M.A. Amin, S.S. Abd El-Rehim, E.E.F. El-Sherbini, S. Bayoumi, “The inhibition of low carbon steel corrosion in hydrochloric acid solutions by succinic acid. Part I. Weight loss, polarization, EIS, PZC, EDX and SEM studies”, Electrochimica Acta 52 (2007) 3588-3600.


Multimetallic Gas Diffusion Electrodes for the CO2- to-CH3OH electrochemical reaction.Sergio Castro.

Sergio Castro1*, Jonathan Albo1, Jose Solla-Gullón2, Vicente Montiel2, Angel Irabien1

1 Department of Chemical & Biomolecular Engineering, University of Cantabria, Avda. Los Castros s/n, 39005 Santander, Spain.2 Institute of Electrochemistry, University of Alicante, Apdo. 99, 03080 Alicante, Spain.

The electrochemical reduction of CO2 has been pointed out as an interesting strategy to convert CO2 into CH3OH, making possible to consider CO2 as a resource and a business opportunity rather than a waste with a cost of disposal. In addition, coupling CO2 electroreduction with renewable energies would allow storing electricity from intermittent renewable sources [1]. Cu and Cu(I)-based electrocatalysts materials have been identified by several researchers as the most promising materials capable of reducing CO2 electrochemically to produce CH3OH. However, CO2 transformation rates and Faradaic efficiencies are still low at Cu-based materials and so, new electrocatalysts are required to enhance the performance of the process.

In this study, we synthesize materials including Cu in combination with other metals (i.e. Au, Ru, Mo and Pd) that are expected to adsorb intermediate species, leading to an enhanced CO2 transformation to alcohols [2]. The different nanomaterials are synthesized in a water-in-oil microemulsion and subsequently supported in carbon (Vulcan XC-72R). Finally, the samples are airbrushed on a carbon microporous layer (also with Vulcan XC-72R) previously fixed onto a porous carbon paper, in order to alleviate mass transport limitations across the gas-liquid interface and catalyst surface [3]. Then, the electrodes are tested in a filter-press cell for the electrochemical reduction of CO2 in continuous operation at different electrolyte flow rates (5-30 ml min-1cm-2), CO2 flow rates (50-300 ml min-1 cm-2) and current density levels (10-40 mA cm-2).

References:1. J. Albo, M. Alvarez-Guerra, P. Castaño and A. Irabien, Towards the electrochemical conversion of carbon dioxide into methanol. Green Chemistry, 2015. 17: p. 2304-2324.2. A. A. Peterson, F. Abild-Pedersen, F. Studt, J. Rossmeisl and J. K. Nørskov, How copper catalyzes the electroreduction of carbon dioxide into hydrocarbon fuels. Energy & Environmental Science, 2010.3: p. 1311-1315.3. J. Albo and A. Irabien, Cu2O-loaded gas diffusion electrodes for the continuous electrochemical reduction of CO2 to methanol. Journal of Catalysis, 2016- 343: p.232-239.

Acknowledgements:The authors gratefully acknowledge financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) through the projects CTQ2013-48280-C3-1-R, CTQ2016-76231-C2-1-R and CTQ2016-76231-C2-2-R, as well as Ramón y Cajal programme (RYC-2015-17080). J.S-G. acknowledges financial support from VITC (Vicerrectorado de Investigación y Transferencia de Conocimiento) of the University of Alicante.

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Oligoethyleneglycol (OEG) chains organization in molecular layers formed on gold substrates.Rafael Madueño.

Sandugash Yergeshbayeva, Miriam Chávez, Guadalupe Sánchez-Obrero, Rafael Madueño, Manuel Blázquez, Teresa Pineda

Departamento Química Física y Termodinámica Aplicada, Instituto de Química Fina y Nanoquímica, Universidad de Córdoba, Ed. Marie Curie, 2ª Planta, Campus de Rabanales, 14014 Córdoba, España.

Oligoethyleneglycol (OEG) films are frequently used in the protection of materials that have applications in biological systems. The main objective is to avoid the unspecific adsorption of proteins. Recently, the use of this type of protection has become of a major relevance because of the attempts of applications of nanomaterials in fields like Bionanomedicine1,2. In this sense, the knowledge of the organization of the OEG chains in the films formed on metallic substrates is of a great interest, in particular, when high molecular weight polymers are used.

There are many reports in the literature dealing with this topic, and, in most of them, it is assumed that these layers are compact and uniform. However, this assumption is not supported by experimental studies and, in the present work we carried out a comparative study of some layers formed on different gold substrates with OEG derivatives of different molecular weight.

The characterization has been made by using electrochemical techniques such as cyclic voltammetry and electrochemical impedance spectroscopy. By using these means, we not only evaluate the ability of the molecular layers to block the access of ions or molecules from solution but they allow us to gain information on the organization degree of the molecules within the layer and the final structure properties.

Moreover, we have studied the molecular organization by using FT-IRRAS spectroscopy. The results obtained allow us to stablish the experimental conditions upon which the OEG chains form crystalline or amorphous structures. The measure-ments of water contact angle evidence the film homogeneity and the reproducibility of the used formation methods.

References:(1) Docter, D.; Westmeier, D.; Markiewicz, M.; Stolte, S.; Knauer, S. K.; Stauber, R. H. The nanoparticle biomolecule corona: lessons learned - challenge accepted? Chem. Soc. Rev. 2015, 44, 6094-6121.(2) O'Connell, D. J.; Bombelli, F. B.; Pitek, A. S.; Monopoli, M. P.; Cahill, D. J.; Dawson, K. A. Characterization of the bionano interface and mapping extrinsic interactions of the corona of nanomaterials. Nanoscale 2015, 7, 15268-15276.

Acknowledgements:Ministerio de Economía y Competitividad (MINECO) (Proyectos CTQ2014-60227-R and CTQ-2015-71955-REDT Red de Excelencia Sensores y Biosensores Electroquímicos), Junta de Andalucía (P10-FQM-6408) y Universidad de Córdoba.


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Improving the stability of Fe rich layered oxides for Sodium Ion batteries.Begoña Silván.

Begoña Silván1, Elena Gonzalo1, Brahim Orayech1, Damien Saurel1

1 CIC Energigune, Albert Einstein 48, 01510 Vitoria-Gasteiz (Basque Country).

The development of the use of alternative (renewable) energy sources and electric vehicles (EVs) is one of the main challenges to reduce the dependency on fossil fuels. Renewable energy sources are usually variable on time, and therefore as well as EVs they require a strong research effort on the secondary battery technology. Similar to the already established lithium-ion secondary battery technology (LIB), sodium-ion battery’s (SIBs) research is growing in the last years as a lower cost alternati-ve.[1-3] Indeed, in addition to its chemical similarities to lithium, sodium is highly available and evenly spread on the earth crust, and allows replacing the copper current collector, used on the anode side in the case of LIBs, for a cheaper aluminum foil.

Sodium based layered oxides have been deeply studied because they are relatively easy to synthesize, versatile and have good specific energies. These materials have not reached the performance of best lithium based equivalents, but since more stable phases have been reported for sodium, there is hope for finding a competitive material on both performance and cost point of view. Great effort is thus being made to improve their electrochemical performance at competitive prices. [4,5]

Iron based NaFeO2 layered oxide is an interesting material due to the low cost and non-toxic nature of iron, its relatively high average voltage (3.3V) and flat voltage-composition profile.[6-8] Moreover, contrary to most layered oxides reported with large specific charge, which usually present about 1/3 sodium deficiency,[5] pristine NaFeO2 is fully sodiated. However, one of the main drawbacks of this material is the quick capacity fading ascribed to irreversible iron migration on the sodium site.[9-11] Furthermore, based on theoretical predictions, Li et al. recently claimed that iron based layered oxides are not electrochemically stable if iron content exceeds one third of the transition metal atom.[9] However, we were able to reversibly cycle NaFeO2 with a capacity retention of 70% after 50 cycles, which is improved up to 95% after 50 cycles with substitutions as low as 10% by other transition metals (TM) on the Fe site.[12]

In addition to the performance of O3 layered oxides of Fe-rich compositions Na1-yFe1-yTMyO2 y≤0.1, a detailed study of the reaction mechanism, the structural changes involved, and its kinetics, will be presented by PITT, impedance spectroscopy and operando XRD.

References:1. V. Palomares et al., Energy Environ. Sci., vol. 6, no. 8, p. 2312, 2013.2. N. Yabuuchi et al., Chem. Rev., vol. 114, no. 23, pp. 11636–11682, 2014.3. M. D. Slater et al., Adv. Funct. Mater., vol. 23, no. 8, pp. 947–958, 2013.4. X. Xiang et al., Adv. Mater., vol. 27, no. 36, pp. 5343–5364, 2015.5. M. H. Han et al., Energy Env. Sci, vol. 8, no. 1, pp. 81–102, 2015.6. Y. Takeda et al., Mater. Res. Bull., vol. 29, no. 6, pp. 659–666, 1994.7. S. Okada et al., in Meeting Abstracts, 2006, pp. 201–201.8. J. Zhao et al., J. Electrochem. Soc., vol. 160, no. 5, pp. A3077–A3081, 2013.9. X. Li et al., Chem. Mater., vol. 28, no. 18, pp. 6575–6583, 2016.10. N. Yabuuchi et al., Electrochemistry, vol. 80, no. 10, pp. 716–719, 2012.11. E. Lee et al., Chem. Mater., vol. 27, no. 19, pp. 6755–6764, 2015.12. B Silván et al., in preparation.

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RGB Video Electrochemistry: Application to deposition and dissolution of Cu on a composite electrode.José J. García-Jareño.

José J. García-Jareño1, Jerónimo Agrisuelas1, Francisco Vicente1

1 Physical Chemistry Department (University of Valencia), Dr. Moliner 50, 46100 Burjassor (Spain).

Color changes on the electrode surface during electrochemical processes were monitored by in situ digital video recordin-g[1]. The evolution of standard red, green, and blue (sRGB) intensity channels extracted from digital images showed a close relationship with the course of the electrochemical dissolution or deposition process. Time derivative sRGB mean intensity (dI/dt) allowed an accurately description of the electrochemical process. Standard deviation of sRGB intensity (std) provided information about the color homogeneity of the studied region on the electrode surface.

Cu was electrodeposited and after, electrodissolved on the surface of a composite material composed by graphite and copper powder randomly dispersed into a polypropylene matrix (CCuPP, 40:10:50 in weigh). The high resistivity of this material and the anions in the outer solution can affect the electrochemical response and also the quality and homogeneity of the electrodeposited material[2–4]

The rate of electrodissolution can be followed by RGB Video Electrochemistry on different zones of the electrode surface. The high resistance of the material causes a non-homogeneous electrodissolution rate. The maximum rate of electrodissolu-tion is achieved at different times on different zones of the electrode surface. Measured potential on the electrode surface changes abruptly after the continuity of the Copper layer electrodeposited is broken.

Independently of the electrode transparency and area, we were able to evaluate the spatial distribution of metal dissolution on a composite electrode. These results show great promise for use in innovative investigations and fast quality controls of electrochromic devices or modified electrodes at low cost.

References:[1] J. Agrisuelas, J.J. García-Jareño, E. Perianes, F. Vicente, Use of RGB digital video analysis to study electrochemical processes involving color changes, Electrochem. Commun. 78 (2017) 38–42. doi:10.1016/j.elecom.2017.04.001.[2] J. NavarroLaboulais, J. Trijueque, J.J. GarciaJareno, F. Vicente, Ohmic drop effect on the voltammetric behaviour of graphite plus polyethylene composite electrodes, J Electroanal Chem. 422 (1997) 91–97.[3] J.J. García-Jareño, J. Navarro-Laboulais, F. Vicente, A numerical approach to the voltammograms of the reduction of Prussian Blue films on ITO electrodes, Electrochimica Acta. 42 (1997) 1473–1480. doi:10.1016/S0013-4686(96)00302-7.[4] J.J. García-Jareño, A. Sanmatías, J. Navarro-Laboulais, F. Vicente, Chronoamperometry of prussian blue films on ITO electrodes: ohmic drop and film thickness effect, Electrochimica Acta. 44 (1999) 4753–4762. doi:10.1016/S0013-4686(99)00226-1.

Acknowledgements:This work was supported by CICyT-FEDER project CTQ2015-71794-R.


Carbon nanodots based biosensors for gene mutation detection.Mª Encarnación Lorenzo.

Tania García-Mendiola1,2,3, José María López Moreno1, Iria Bravo1,2, Félix Pariente1,3, Reinhold Wannemacher2, Dana Cialla-May4,5, Jürgen Popp4,5 and Encarnación Lorenzo1,2,3

1 Departamento Química Analítica y Análisis Instrumental. 2 Institute for Advanced Research in Che-mical Sciences (IAdChem) of Universidad Autónoma de Madrid. 3 Instituto Madrileño de Estudios Avanzados (IMDEA).4 Leibniz Institute of Photonic Technology (IPHT), Institute for Physical Che-mistry and Abbe Center of Photonics. 5 Friedrich-Schiller-University Jena, Germany.

Carbon dots (CDs) are defined as nanoparticles mainly composed of carbon, with a size below 10 nm [1]. Nanomaterial-modi-fied detection systems represent a chief driver towards the adoption of electrochemical methods for sensing applications [2,3]. In this work, an electrochemical DNA biosensor constructed by using a carbon nanodots (CDs) modified screen-printed gold electrode is reported. CDs were synthesized by thermal carbonization of ethylene glycol bis-(2-aminoethyl ether)-N,N,N’,N’-te-traacetic acid and characterized by different techniques. The electrode surface modification was accomplished by drop-casting a suspension of CDs. Synthetic 25-mer or 100-mer DNA capture probes from the pathogen Helicobacter pylori or the cystic fibrosis transmembrane regulator (CFTR) gen were attached to the CDs-gold surface. A 25 bases synthetic sequence or a 373 bases PCR amplicons of exon 11 of CFTR containing a sequence complementary to the capture probe, were employed as target sequences. The hybridization event was electrochemically monitored by using Safranine as redox indicator. The biosen-sor has been applied to the detection of F508del mutation in the CFTR gen.

References:1. Baker, S.N.; Baker, G.A. Angew. Chem., Int. Ed.2010, 49, 6726–6744, 10.1002/anie.200906623.2. Milosavljevic, V.; Nguyen, H.V.; Michalek, P.; Moulick, A.; Kopel, P.; Kizek, R.; Adam, V. Chem. Pap. 2015, 69, 192-201, 10.2478/s11696-014-0590-2.3. Shen, J.; Zhu,Y.; Yang, X.; Li, C. Chem. Commun. 2012, 48, 3686–3699, 10.1039/c2cc00110a.

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RGB video electrochemistry: Application to electrochromic conducting polymers. Jerónimo Agrisuelas.

Jerónimo Agrisuelas1, José Juan García-Jareño1, Estefanía Perianes1, Francisco Vicente1

1Departament de Química Física, Universitat de València.C/ Dr. Moliner, 50, 46100, Burjassot, València, Spain

The electrochromic changes of poly(o-toluidine), a polyaniline-derivative, deposited on a transparent indium-tin oxide (ITO) electrode have been monitored by in situ digital video recording at 25 frames per seconds [1]. This allowed us to investigate the fast electrochromic changes of poly(o-toluidine) films during voltammetry and chronoamperometry experiments. Image analysis acquired by digital video at short time intervals allowed the evolution of standard red, green, and blue channels (sRGB) intensity to be analyzed. The mean sRGB intensity extracted from digital images showed a close relationship with the course of the electrochemical processes. On the one hand, time derivative sRGB mean intensity showed a very good correlation with current peaks and shoulders of cyclic voltammogram identifying the intermediate forms in poly(o-toluidine). The leucoemeral-dine to polaron transition was monitored by changes of the time-derivative mean blue intensity, the polaron to bipolaron transition was monitored by changes of the time-derivative mean red intensity and the bipolaron to pernigraniline transition was monitored by changes of the time-derivative mean blue and green intensities [2,3]. This information could be used to deconvolute multistep electrochromic reactions. On the other hand, the standard deviation of sRGB intensity provided interes-ting information of color homogeneity of the electrode region studied. Faster color changes took place at the upper region of poly(o-toluidine) modified ITO electrode regarding the lower region due to the ohmic drop of ITO electrode [4]. These results show great promise for use in innovative investigations and fast quality controls of electrochromic devices or modified electro-des at low cost.

References:[1] J. Agrisuelas, J.J. García-Jareño, E. Perianes, F. Vicente, Use of RGB digital video analysis to study electrochemical processes involving color changes, Electrochem. Commun. 78 (2017) 38–42. doi:10.1016/j.elecom.2017.04.001.[2] J. Agrisuelas, C. Gabrielli, J.J. García-Jareño, H. Perrot, F. Vicente, Kinetic and Mechanistic Aspects of a Poly(o-toluidine)-Modified Gold Electrode. 1. Simultaneous Cyclic Spectroelectrochemistry and Electrogravimetry Studies in H2SO4 Solutions, J. Phys. Chem. C. 116 (2012) 15620–15629. doi:10.1021/jp303858q.[3] J. Agrisuelas, C. Gabrielli, J.J. García-Jareño, H. Perrot, F. Vicente, Effects of anions size on the redox behavior of poly(o-toluidine) in acid solutions. An in situ vis-NIR cyclic spectroelectrogravimetry study, Electrochimica Acta. 125 (2014) 83–93. doi:10.1016/j.electacta.2014.01.036.[4] J.J. García-Jareño, A. Sanmatías, J. Navarro-Laboulais, F. Vicente, Chronoamperometry of prussian blue films on ITO electrodes: ohmic drop and film thickness effect, Electrochimica Acta. 44 (1999) 4753–4762. doi:10.1016/S0013-4686(99)00226-1.

Acknowledgements:This work was supported by CIC y T-FEDER project CTQ2015-71794-R


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Nuevos Materiales Compuestos Basados en Grafeno como ánodos para baterías de ión litio.Cristina Botas.

C. Botas1, D. Carriazo1,2, G. Singh1, T. Rojo1,3

1 CIC Energigune, Albert Einstein 48, 01510 Vitoria-Gasteiz. 2 IKERBASQUE, Fundación Vasca para la Ciencia, Bilbao. 3 Facultad de Ciencia y Tecnología (UPV/EHU), Bilbao.

El desarrollo de nuevos dispositivos portátiles, como móviles, ordenadores o coches, está asociado al desarrollo de nuevos sistemas de almacenamiento de energía más ligeros, duraderos y seguros. Para ello, una de las estrategias que se siguen actualmente es el desarrollo de nuevos materiales electródicos para baterías de ión litio (LIBs). En este contexto, materiales como el estaño [1-2] o el silicio [3] están siendo estudiados, pues presentan capacidades teóricas muy elevadas (993 y 3579 mAh·g-1, respectivamente), baja toxicidad y bajo coste; siendo su expansión volumétrica durante la carga y la descarga (hasta 300%) su principal inconveniente, ya que esto provoca la desintegración del electrodo, lo que se traduce en una ciclabilidad muy baja [1-3]. Este problema puede ser solventado mediante el empleo de una matriz de carbono que acomode la expansión volumétrica. Los materiales basados en grafeno están demostrando ser muy adecuados para este fin gracias a su alta conducti-vidad eléctrica y difusividad química al litio [1-2].

Así, el objetivo principal del presente trabajo fue la preparación de nuevos materiales compuestos SnO2-óxido de grafeno reduci-do (rGO) y Si-rGO, donde el rGO actúa como matriz para acomodar los cambios de volumen, a la vez que mejora la conduc-tividad y permite desarrollar electrodos autosoportados libres de aglutinantes. Los nuevos materiales, rGO, SnO2-rGO [3] y Si-rGO [5], fueron caracterizados fisicoquímica y electroquímicamente. En la figura 1 se puede observar que los materiales compuestos presentan una composición homogénea. Estos materiales autosoportados fueron testeados directamente como ánodos en semiceldas de LIBs, sin necesidad de emplear ningún aditivo (sin aglutinantes o aditivos conductores). La capacidad reversible obtenida a 50 mA·g-1 fue de 298 mAh·g-1 para el rGO y 650 mAh y 750 mAh por gramo total de electrodo (1815 mAh y 1875 mAh por gramo de material activo) para el SnO2-rGO [3] y el Si-rGO [5], respectivamente (Fig. 1).

Fig. 1. Imágenes de SEM de los materials compuestos a) SnO2@rGO y b) Si@rGO. c) Evolución de la capacidad de carga y descarga y las eficiencias culombicas asociadas medidas para los electrodos autosoportados de rGO, SnO2@rGO and Si@rGO.

References:1. C. Botas, D. Carriazo, G. Singh, T. Rojo, Journal of Materials Chemistry A, 3, 13402, (2015).2. E. Quesnel et al., 2D Materials 2, 030204 (2015).3. C. Botas et al. ACS Applied Materials & Interfaces, 8, 28800, (2016).

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Análisis de la presencia de interacciones intermoleculares en monocapas electroactivas mediante técnicas de multipulso de potencial.Joaquín González.

Joaquín González1, Alfonso Sequí1, Francisco Martínez Ortíz1

1 Departamento de Química Física, Facultad de Química, Universidad de Murcia, 30100 Espinardo, Murcia.

La modificación de superficies conductoras mediante la inmovilización de especies electroactivas permite diseñar interfases con nuevas y muy variadas funcionalidades para su aplicación a un gran número de situaciones de interés [1]. La caracteri-zación electroquímica de estos sistemas da lugar con frecuencia a la obtención de respuestas que no coinciden con las correspondientes a un modelo “ideal”. De entre las diferentes causas de no-idealidad, una de las más frecuentes es la presencia de interacciones intermoleculares entre adsorbatos [2]. Dichas interacciones pueden obedecer a la heterogenei-dad del entorno de las especies electroactivas debidas a una solvatación no uniforme de las mismas o la existencia de apantallamientos electrostáticos no efectivos.

La modelización fenomenológica de estas interacciones fue llevada a cabo, entre otros, por Laviron [3], que propuso expresiones sencillas para la corriente y los excesos de especies electroactivas en función de un único parámetro de interac-ción cuando la transferencia de carga es muy rápida (límite nernstiano). Así, el estudio de este tipo de no-idealidades se ha realizado típicamente en Voltametría Cíclica, la cual permite obtener de manera sencilla respuestas corriente-potencial muy sensibles a la presencia de interacciones. No obstante, la corriente obtenida en esta técnica puede verse afectada de forma compleja por procesos no faradaicos que pueden llegar a notoriamente en la respuesta [4].

En esta comunicación presentamos la aplicación del modelo de interacciones de Laviron al caso de técnicas de multipulso de potencial, y en particular, a aquellas basadas en la medida de la carga asociada a la conversión redox de una especie fuertemente adsorbida, ya que dichas técnicas permiten una caracterización precisa del comportamiento en el límite nernstiano, así como la determinación de los diferentes parámetros del sistema. En particular, hemos considerado las técnicas “Voltaculometría de Escalera Diferencial” y “Voltaculometría de onda cuadrada”, las cuales permiten obtener respuestas con forma de pico de cuyos parámetros pueden determinarse de forma sencilla el exceso de especie electroacti-va así como el parámetro de interacción.

Referencias: 1. J. Gooding, S. Ciampi, Chemical Society Reviews, 40 (2011) 222. J. J. Calvente, R. Andreu, Current Opinion in Electrochemistry, 1 (2017) 22-263. E. Laviron, Journal of Electroanalytical Chemistry 52 (1974) 3954. A. Molina, J. González, Pulse Voltammetry in Physical Electrochemistry and Electroanalysis, Springer, 2016

Agradecimientos: Los autores desean expresar su agradecimiento a la Fundación SENECA (Proyecto 19887/GERM/15) y al Ministerio de Economía y Competitividad (CTQ2015-65243-P)


Dual range lactate oxidase-based screen printed biosensor for analysis of diverse samples.Hugo Silva.

H. Silva1, M.J. Arcos-Martínez1

1 Analytical Chemistry Department, Faculty of Sciences, University of Burgos, Burgos (Spain).

Lactate (LA), is a biological metabolite, relevant in several areas, such as, sports medicine and health care applications, in food industry, and even cosmetic. Due to the diversified samples with LA content, the determination of this organic acid is usually carried out in different concentration ranges. For example, in clinical exercise and performance testing, as a non-invasive alternative for blood sampling, the LA can be determined via sweat or saliva analysis, whose concentration vary from small 0.1 mM of LA in saliva, up to 50 mM in perspiration. Also, in food industry, malolactic fermentation that can result in higher LA content in red wines, than the one observed in white wines [1,2].

In the present work, 0.25U of lactate oxidase (LOx) crosslinked in a chitosan layer, leads to an efficient determination of the enzymatic product formed at a platinum modified working electrode at +0.15 V (vs SPE Ag/AgCl). The method reproducibility is kept below 7%, and a limit of detection of 0.75 µM for the first zone was obtained. The developed screen-printed LOx-ba-sed biosensor proves to respond linearly in two concentration ranges for LA analysis; from 0.75 µM to 1mM, followed by a saturation zone from 1 mM to 4mM, and a second range resulting from the enzyme inhibition by its substrate up to 50 mM (fig.1). The biosensor proves to offer good selectivity by avoiding interferents, and by successfully determine lactate content in real samples as sweat and saliva, offering a noninvasive analysis, and, in red and white wines.

Fig.1. (A) Schematic representation of LOx reaction on electrode surface, (B) Amperometric signal of enzymatic response for lactate at +0.15V (vs SPE Ag/AgCl).

References:1. Guilbault, G.G., Palleschi, G., Lubrano, G., 1995. Non-invasive biosensors in clinical analysis. Biosens. Bioelectron. 10, 379–392.2. Pérez, S., Fàbregas, E., 2012. Amperometric bienzymatic biosensor for l-lactate analysis in wine and beer samples. Analyst. 137, 3854.

Acknowledgements:Authors would like to acknowledge funding obtained through the Spanish Ministry of Science and Innovation (MICINN) and the European Regional Development Fund (FEDER) (TEC20013-40561-P.). H. Silva, would like to acknowledge funding granted through his MICINN scholarship FPI.

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Desarrollo de un equipo de espectroelectroquímica Raman resuelta en el tiempo.Juan V. Perales.

Juan V. Perales1, David Ibáñez1, Alejandro Junquera2, Pablo Fanjul2, Álvaro Colina1, Aránzazu Heras1

1 Departamento de Química, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, España.2 DropSens S.L Edificio CEEI - Parque Tecnológico de Asturias - 33428 Llanera (Asturias) Spain.

El Grupo de Análisis Instrumental de la Universidad de Burgos en colaboración con DropSens S.L. ha desarrollado un nuevo instrumento totalmente integrado de Espectroelectroquímica Raman resuelta en el tiempo. La Espectroelectroquímica Raman es una técnica muy prometedora que ha sido ampliamente utilizada para resolver diferentes problemas químicos [1]. Los instrumentos típicos de Espectroelectroquímica Raman son desarrollados por los grupos de investigación mediante la combinación de un instrumento electroquímico con un espectrofotómetro Raman. Existen algunas soluciones comerciales en las que siempre se combinan dos instrumentos independientes. Siguiendo la filosofía desarrollada en el primer instrumento compacto de espectroelectroquímica de absorción en el UV/Vis, en este nuevo trabajo se ha desarrollado un equipo compacto con un software específico que permite no sólo un control único de la parte eléctrica y óptica, sino que también permite realizar, de un modo muy sencillo e intuitivo, el análisis de los experimentos. El correcto funcionamiento del nuevo instrumento ha sido demostrado usando sistemas electroquímicos conocidos que habitualmente se utilizan para la validación de equipos espectroelectroquímicos.

Figura 1. Equipo compacto de espectroelectroquímica Raman resuelta en el tiempo.

Referencias: 1. D. Ibañez, J. Garoz-Ruiz, A. Heras, A. Colina, Anal. Chem. 2016, 88, 8210–8217.

Agradecimientos: Este trabajo ha sido realizado gracias a la financiación de la Junta de Castilla y León (BU033-U16) y del Ministerio de Economía y Competitividad (CTQ2014-61914-EXP, CTQ2014-55583-R, TEC2014-51940-C2-2R, CTQ2015-71955-REDT).

New electrolytes for Aluminium-based batteries: towards rechargeability. Mikel Pino.

M. Pino*, A. López-Cudero*, F.J. Pérez-Alonso, P. Rodriguez

ALBUFERA ENERGY STORAGE. C/ Faraday 7, 28049 Madrid.

Aluminium-based batteries are of great interest due to a number of potential advantages, such as: (i) Its oxidation gives up to 3 electrons, versus just one in the case of Lithium; (ii) it has a high theoretical voltage of 2.7 V (operation voltage being 1,2V similar to the market-available Zn batteries), (iii) a very high Specific Energy (8000 Wh/kg) and (iv) are low cost.

However, in aqueous-based solutions, the formation of a very stable oxidation product hinders the possibility of a reversible process, necessary to obtain a rechargeable battery. Therefore, the chal-lenge of obtaining secondary Aluminium-based batteries can only become a reality if other sort of electrolyte is used.

With this aim, we have selected and studied a large number of electrolytes, including ionic liquids, organics, and deep eutectic solvents, with the focus put in the electrodeposition and stripping of Alu-minium. Electrochemical techniques such as cyclic voltammetry and chronopotentiometry have been used, along with charge/discharge cycles in a battery conformation, in order to test performance of electrodes, electrolytes and battery as a full.

As an example, Figure 1 presents the cyclic voltammograms of Al in three different types of electro-lytes: an organic electrolyte, a Deep Eutectic Solvent (DES) and an Ionic Liquid. These results clearly show that electrodeposition and stripping of Aluminum is possible, provided the correct electrolyte is chosen, and our results pave the way towards obtaining a secondary battery based in Aluminium in a near future.

Fig1. Stripping/Electrodeposition of Al in different electrolytes.

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6

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Estudio Teórico del Mecanismo de Transferencia Iónica ECeqC en Macrointerfases Líquido|Líquido.Ángela Molina.

A. Molina1, E. Torralba1, J.M. Olmos1, E. Laborda1

1 Campus de Excelencia Internacional ‘‘Campus Mare Nostrum’’, Universidad de Murcia, Murcia (España).

Desde los trabajos pioneros de Koryta y otros autores [1,2], la disminución de la energía de Gibbs de transferencia iónica a través de interfases entre dos disoluciones electrolíticas inmiscibles (ITIES) ha sido un importante campo de investigación. Así, el estudio de ligandos o ionóforos que ‘faciliten’ la transferencia de iones poco lipófilos mediante la formación de complejos en la fase orgánica es de relevancia en el desarrollo de procesos de extracción líquido-líquido, catálisis de transfe-rencia de fase o electrodos selectivos de iones.

En esta comunicación se analizará un mecanismo de transferencia iónica en el que el ión transferido (un protón) experimen-ta dos reacciones consecutivas en la fase orgánica (mecanismo ECeqC dado en el Esquema I). Este mecanismo presenta un gran interés ya que está íntimamente relacionado con la respuesta obtenida en la transferencia asistida de protón por decametilferroceno (DMFc), el cual actúa como base lipofílica tanto en ausencia como en presencia de oxígeno [3]. En ausencia de oxígeno, el DMFcH+ producido en la fase orgánica evoluciona en una subsiguiente reacción química por la que tiene lugar la producción de H2.

Mediante un tratamiento matemático analítico del problema cinético-difusivo correspondiente al mecanismo de transferen-cia indicado en el Esquema I, se ha obtenido una solución analítica (ec. (1)) para la respuesta corriente-potencial-tiempo:

donde es la constante de disociación ácida del ionóforo, es el sobrepotencial adimensional aplicado y:

A partir de la expresión deducida, se analizará la influencia de las principales variables del sistema sobre la respuesta del mecanismo ECeqC en voltametría de pulso normal (NPV) y se identificarán y discutirán casos particulares y límite de su comportamiento.

Referencias: 1. J. Koryta, Electrochim. Acta 24 (1979) 2932. A. Molina, C. Serna, J. A. Ortuño, E. Torralba, Annu. Rep. Prog. Chem., Sect. C: Phys. Chem. 108 (2012) 1263. I. Hatay, B. Su, F. Li, R. Partovi-Nia, H. Vrubel, X. Hu, M. Ersoz, H.H. Girault, Angew. Chem. Int. Ed. 48 (2009) 5139

Agradecimientos: Los autores agradecen la financiación de la Fundación Séneca de la Región de Murcia (19887/GERM/15) y del Ministerio de Economía y Competitividad (CTQ-2015-65243-P y Juan de la Cierva-Incorporación).

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Caracterización de la proteína citocromo b5-1 de Chlamidomonas reinhardtii (cr-Cytb5-1) y su interacción con nanopartículas de oro.Rafael del Caño.

Rafael del Caño1, Guadalupe Sánchez-Obrero1, Rafael Madueño1, Manuel Blázquez1, Teresa Pineda1, Alejandro Chamizo-Ampudia2, Aurora Galván2, Ángel Llamas2, Emilio Fernández2

1 Dpto. Química Física y T. A., Instituto Química Fina y Nanoquímica. Ed. Marie Curie, 2ª Planta. 2 Dpto. Bioquímica y Biología Molecular, Ed. Severo Ochoa, 1ª Planta. Campus de Rabanales, Universidad de Córdoba. 14014 Córdoba, España.

Las proteínas ARC (componente reductor de amidoxina) catalizan la reducción de un amplio número de compuestos N-hidroxi-lados (NHC), usando el poder reductor suministrado por otras proteínas. A diferencia de Escherichia coli que contiene un dominio ferredoxina y requiere NADPH-flavin-reductasa para reducir estos compuestos tóxicos, en humanos falta el dominio ferredoxina y se requiere un citocromo b5 (cytb5) y una NADH-citb5 reductasa. En Chlamidomonas reinhardtii (cr) existen seis ferredoxinas pero se ha demostrado que no son necesarias para que crARC reduzca NHCs. En cambio, posee cinco cytb5 y dos flavin-reductasas, cr-cytb5-R que reducen NHCs. De hecho, cytb5-R con ARC y cytb5-1 son capaces de reducir NHC tomando los electrones de NADH.[1,2]

Cytb5 es una proteína anfipática que posee dos dominios, un dominio soluble en agua que posee un grupo hemo y un dominio hidrofóbico de anclaje a la membrana en su extremo C-terminal. Para facilitar su solubilidad, este dominio se ha truncado.

En el presente trabajo, se lleva a cabo un estudio de caracterización físico-química de la proteína cr-cytb5-1 en disolución acuosa. Los estudios mediante espectroscopía UV-visible permiten obtener las condiciones experimentales donde la proteína es estable. Además, se ha ensayado el comportamiento de cr-cytb5-1 en función del pH de la disolución midiendo las variacio-nes del potencial-zeta, obteniéndose el punto isoeléctrico de la proteína. Uno de los puntos de más interés en los estudios de hemo-proteínas es conocer sus propiedades redox. En este sentido, se ha comprobado que la proteína cr-cytb5-1 depositada sobre un electrodo de grafito no muestra transferencia electrónica cuando se lleva a cabo el experimento en condiciones fisiológicas. En cambio, cuando cr-cytb5-1 interacciona con nanopartículas de oro formando un bioconjugado estable, muestra señal redox observable mediante voltamperometría cíclica. Este comportamiento se debe a que la proteína se adapta a la forma de la nanopartícula y se produce una orientación favorable que permite establecer una buena comunicación con el núcleo metálico de oro.

Referencias:(1) Chamizo-Ampudia, A.; Galvan, A.; Fernandez, E.; Llamas, A. The Chlamydomonas reinhardtii Molybdenum Cofactor Enzyme crARC Has a Zn-Dependent Activity and Protein Partners Similar to Those of Its Human Homologue. Eukaryotic Cell 2011, 10, 1270-1282.(2) Chamizo-Ampudia, A.; Galvan, A.; Fernandez, E.; Llamas, A. Study of Different Variants of Mo Enzyme crARC and the Interaction with Its Partners crCytb5-R and crCytb5-1. Inter. J. Molec. Sci. 2017, 18.

Agradecimientos:Ministerio de Economía y Competitividad (MINECO) (Proyectos CTQ2014-60227-R and CTQ-2015-71955-REDT Red de Excelencia Sensores y Biosensores Electroquímicos), Junta de Andalucía (P10-FQM-6408) y Universidad de Córdoba.

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Iodine-mediated electrochemical detection of thiols in plant extracts using platinum screen-printed electrodes.Edelmira Valero.

Edelmira Valero1, Mª Isabel González Sánchez1, Richard G. Compton2

1 Departament of Physical Chemistry, School of Industrial Engineers, University of Castilla-La Mancha, Campus Universitario de Albacete, 02071-Albacete (Spain).2 Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, United Kingdom.

Thiols (-SH) are the main form of reduced sulphur in plants and can be found as protein thiols (thioredoxins) and low molecular weight thiols (cysteine, glutathione or phytochelatins). These compounds play important roles in the stress response of plants and their adaptation to the environment. Thiols can be oxidized to disulfides (-S-S-) and the oxidized/re-duced couple ratio is regarded as an important biochemical marker for the evaluation of the oxidative stress levels in biological samples [1].

In the present communication, we report an electroanalytical methodology for determining this ratio using cyclic voltamme-try and platinum screen-printed electrodes. The method involves the use of the reaction of electro-generated iodine with biological thiols, using glutathione (GSH) as a model, which produces an increase in the current of the anodic peak from iodide oxidation, and allows its easy analytical quantification. Iodine reacts with thiols in its reduced state, but not with disulfides [2], making possible the discrimination of these two kinds of compounds in a mixture. For the total glutathione determination (tGSH), sodium borohydride was added to the sample as a reducing agent. Calibration plots for the reduced and total glutathione were analyzed. It was demonstrated that this method is able to analyze these compounds in solutions spiked with reduced and oxidized glutathione. Finally, to test the effectiveness of the analytical method in real samples, plant extracts from Pisum sativum (pea) were analyzed by the developed methodology as a proof-of-concept and validated independently with a spectrophotometric method. The results of this work have been recently published in Sensors & Actuators B: Chemical [3].

Funding source: Spanish Ministry of Economy and Competitiveness (MINECO, http://www.mineco.gob.es/portal/site/mine-co/idi), Projects No. BFU2013-44095-P and BFU2016-75609-P (cofunded with FEDER funds, EU).

Referencias: 1. Valero E, Macià H, De la Fuente IM, Hernández JA, González-Sánchez MI, García-Carmona F. Modeling the ascorbate-glutathione cycle in chloroplasts under light/dark conditions. BMC Systems Biology. 2016,10.2. Valero E, González-Sánchez MI, Batchelor-McAuley C, Compton RG. Halogen mediated voltammetric oxidation of biological thiols and disulfides. Analyst. 2016, 141:144-149.3. González-Sánchez MI, Valero E, Compton RG. Iodine mediated electrochemical detection of thiols in plant extracts using platinum screen-printed electrodes. Sensors & Actuators B: Chemical 2016, 236: 1-7.


Chalcogenide based photocathodes for solar water splitting. Teresa Andreu.

Teresa Andreu1,2*, Carles Ros1, Sergio Girado1, Haibing Xie1, Yudania Sánchez1, Nina Carretero1, Victor Izquierdo1, Edgardo Saucedo1, J.R. Morante1,2

1 Catalonia Institute for Energy Research, IREC, Jardins de les Dones de Negre 1, 08930 Sant Adrià de Besòs, Barcelona, Spain.2 Universitat de Barcelona, Martí i Franquès, 1, 08028 Barcelona, Spain.

An important approach towards an efficient and sustainable economy is storing solar energy into chemical fuels through photoelectrochemical (PEC) water splitting. Cheap and earth abundant materials, optimal band gap and electrolyte adaptabili-ty is mandatory for large scale industrialization and deployment of PEC technology.

Mathematical calculations have shown that dual absorber tandem photocathode/photoanode configurations could overcome the required efficiencies for large scale industrialization[1]. Chalcopyrite CI(G)S, and its earth abundant similar, kesterite CZTS/Se solar cells bandgap can be tuned from 1.0 to 1.5 eV with stoichiometric modification[2], with state of the art efficien-cies ranging over 20 %. This versatility makes them very interesting to be implemented in PEC water splitting[3]. In this work, we demonstrate that titanium dioxide grown by ALD can be used as a transparent protective and conductive layer for having a high throughput CZTS/Se and CIGSe based photocathodes for water splitting. The role of i-ZnO and AZO layers in the electron transport mechanisms through the deposited TiO2 film has been also evaluated. Furthermore, TiO2 protected photoca-thodes have been tested in electrolytes with pH ranging from 0.3 to 14, presenting promising stability results.

Fig. 1. Stability test at 0 V vs RHE (a) and Cross section of a CZTS/CdS/ITO/TiO2 sample (b)

References:[1] S. Hu, C. Xiang, S. Haussener, A. D. Berger, and N. S. Lewis, Energy Environ. Sci., vol. 6, no. 10, p. 2984, Sep. 2013.[2] S. Giraldo, M. Neuschitzer, T. Thersleff, S. López-Marino, Y. Sánchez, H. Xie, M. Colina, M. Placidi, P. Pistor, V. Izquierdo-Roca, K. Leifer, A. Pérez-Rodríguez, and E. Saucedo, Adv. Energy Mater., vol. 5, no. 21, pp. 1–6, 2015.[3] C. Ros, T. Andreu, S. Giraldo, Y. Sánchez, and J. R. Morante, Sol. Energy Mater. Sol. Cells, pp. 1–5, 2016

Acknowledgements:This work was supported by the European Regional Development Funds (ERDF, FEDER) a and MINECO project WINCOST ENE2016-80788-C5-5-R.

500 nm

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Tratamiento Teórico de la Respuesta Voltamétrica de Transferencias Multi-Electrónicas con Equilibrios Químicos Acoplados en Microelectrodos.Eduardo Laborda.

E. Laborda1, A. Molina1, J.M. Gómez-Gil1, E. Torralba1

1 Campus de Excelencia Internacional ‘‘Campus Mare Nostrum’’, Universidad de Murcia, Murcia (España).

Se presenta una solución teórica general y sencilla para el estudio de la respuesta voltamétrica de transferencias multi-electró-nicas reversibles en microelectrodos, incluyendo la posibilidad de que dichas transferencias estén complicadas por uno o varios equilibrios químicos acoplados. Ésta es una situación frecuente en medidas electroquímicas ya que las especies bajo estudio suelen estar involucradas en procesos de protonación, asociación iónica, isomerización, complejación, etc. [1] En el caso de especies multivalentes, el estudio de la influencia de dichos procesos químicos sobre la estabilidad de los distintos estados de oxidación es de especial relevancia ya que define el carácter reductor/oxidante de los mismos en condiciones reales de trabajo con implicaciones, por ejemplo, en su posible actividad electrocatalítica [2].

La solución teórica que se deduce en esta comunicación es aplicable cualquiera que sea el número de electrones transferidos, la técnica voltamétrica, la escala temporal del experimento (condiciones transitorias o estacionarias), y la geometría del microelectrodo [3], incluyendo también arrays de los mismos. En primer lugar, se discutirá la influencia del tamaño y de la forma (disco, banda, hemi-esfera, cilindro) del microelectrodo sobre la respuesta en voltametría cíclica y voltametrías diferen-ciales (de onda cuadrada y de pulso diferencial, principalmente). El estudio se ilustrará con sistemas experimentales de especial interés como nano-clúster metálicos, electro-catalizadores moleculares y nano-partículas funcionalizadas. A continuación, se analizará la influencia de la actividad química en disolución de los diferentes estados de oxidación sobre la respuesta voltamé-trica, y se discutirán procedimientos y técnicas adecuados para la caracterización de los correspondientes equilibrios químicos. Esto implica la estimación de las estequiometrías y constantes termodinámicas, lo cual no es sencillo cuando la química de las especies electroactivas en disolución incluye múltiples equilibrios e incluso equilibrios competitivos (Esquema I).

Referencias:1. D. Evans, Chem. Rev. 90 (1990) 7392. Q. Li, C. Batchelor-McAuley, N. S. Lawrence, R. S. Hartshorne and R. G. Compton, Chem. Commun. 47 (2011) 114263. A. Molina, J. Gonzalez, M.C. Henstridge, R.G. Compton, 115 (2011) 4054

Agradecimientos:Los autores agradecen la financiación de la Fundación Séneca de la Región de Murcia (19887/GERM/15) y del Ministerio de Economía y Competitividad (CTQ-2015-65243-P, CTQ-2012-36700, Juan de la Cierva-Incorporación y Ayuda de Formación de Profesorado Universitario).

Esquema I

88


Influencia del pH y de la temperatura sobre el par redox Fe(III)/Fe(II) de la Peroxidasa del Tabaco inmovilizada sobre Grafito.José Luis Olloqui-Sariego.

José Luis Olloqui-Sariego1, Galina S. Zakharova2,Andrey A. Poloznikov3, Juan José Calven-te1, Dmitry M. Hushpulian3, Lo Gorton4, Rafael Andreu1

1 Department of Physical Chemistry. University of Sevilla. Profesor García González, 1, 41012, Sevilla. Spain.2 A.N. Bach Institute of Biochemistry, RAS, Leninsky prospect 33/2, Moscow, 119071, Russia.3 Department of Chemistry, Lomonosov Moscow State University, Vorobevy gory 1, Moscow, 119991, Russia.4 Department of Biochemistry and Structural Biology. Lund University, Box 118, 221 00, Lund, Sweden.

En una publicación reciente [1] hemos mostrado cómo se puede mejorar la estabilidad y la actividad electrocatalítica de la Peroxidasa del Tabaco mediante la inmovilización covalente de dímeros de dicha proteína sobre un electrodo de grafito pirolítico. Estas mejoras se deben probablemente a la combinación de una mayor capacidad de retención del grupo heme por la nueva estructura proteica, junto con la adopción preferente de unaorientación más favorable para el intercambio electrónico con el electrodo. Desde un punto de vista más fundamental, esta estrategia de inmovilización permite analizar por primera vez el comportamiento voltamperométrico del centro heme de esta proteína, a través de la respuesta del par redox Fe(III)/Fe(II),sin necesidad de activar el ciclo electrocatalítico que requiere la presencia de peróxido de hidrógeno en disolución [2].

La variación del potencial de semiconversión redox (E1/2) de la proteína con el pH muestra dos tramos lineales paralelos, separa-dos por unidades de pH en el intervalo 4 < pH < 6. Dicha variación puede describirse mediante dos equilibrios de intercambio protónico, uno asociado a la forma reducida con un pKa~ 3.2, y otra asociada a la forma oxidada con un pKa~ 6.4. Este comportamiento es análogo al descrito para las isoenzimas A y C de la peroxidasa del rábano, aunque desplazado hacia disoluciones más ácidas.A su vez, la variación de los potenciales de semiconversiónredox con la temperatura da lugar a valores más pequeños de los incrementos de entalpía y de entropía de reducción que los descritos para otras peroxidasas. En este mismo sentido, el análisis de la variación de la velocidad de transferencia electrónica con la temperatura indica que dicha transferencia está gobernada por un valor bajo de la energía de reorganización (~0.3 eV), pudiéndose concluir que el cambio en el estado de oxidación de la proteína está acompañado por variaciones muy pequeñas de su grado de solvatación y estruc-tura molecular.

Referencias: 1.J. L. Olloqui-Sariego, G. S. Zakharova, A. A: Poloznikov, J. J. Calvente, D. M. Hushpulian, L. Gorton, R. Andreu, Anal. Chem. 87 (2015) 10807 10814.2. J. Castillo, E. E. Ferapontova, D. M. Hushpulian, F. Tasca,V. Tishkov, T. Chubar, I. Gazaryan, L. Gorton. J. Electroanal. Chem. 588 (2006) 112−121.

Agradecimientos:Los autores expresan su agradecimiento al Ministerio de Economía y Competitividad (MINECO) y al FEDER de la Unión Europea por la financiación de los proyectos CTQ2014-52641-P y CTQ2015-71955-REDT (ELECTROBIONET), y al Swedish Research Council por la financiación del proyecto 2014-5908.

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Measurement of total antioxidant capacity by electrogenerated iodine at screen-printed electrodes.María Isabel González.

María Isabel González Sánchez1, Jerónimo Agrisuelas1, Richard Compton2, Edelmira Valero1

1 Departament of Physical Chemistry, School of Industrial Engineers, University of Castilla-La Mancha, Campus Universitario de Albacete, 02071-Albacete (Spain).2 Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, United Kingdom.

Total antioxidant capacity is an important parameter for the evaluation of the oxidative status in different kinds of biological samples [1] such as plants, food, plasma, saliva, etc. Different analytical methods are used to determine the antioxidants content including colorimetry, fluorescence and chemiluminescence. However, these methods have some disadvantages such as interferences from color and turbidity of samples. As an alternative, electroanalytical methods are cheap, technically straigh-tforwardh and having good sensitivity [2].

We present a fast, easy, cost-effective electroanalytical method to measure total antioxidant capacity, based on the reaction of natural antioxidants with electrogenerated iodine using disposable platinum screen-printed electrodes. This reaction can be measured by the increment of the electrochemical current signal of iodide oxidation to iodine during a voltammetric cycle. Iodine reacts with reducing compounds such as glutathione, ascorbate, gallic acid and NADH without interference of the corresponding oxidized counter-parts. Micromolar limits of detection were obtained for all the compounds (7-22 µM). Total antioxidant capacity was expressed as ascorbate equivalents, obtaining a linear calibration (I-I0 (µA) = (0.069 ± 0.002) [ASC] (µM) with a limit of detection of 16.9 µM. Furthermore, the addition of the enzyme ascorbate oxidase also allows the concen-tration of ascorbate to be determined. The method was tested with synthetic samples and real samples of plant extracts growth under non-stress and stressful conditions, and the results correlated well with those obtained with a standard spectro-photometric method. The results of this work have been recently published in the journal Electroanalysis [3].

Funding source: Spanish Ministry of Economy and Competitiveness (MINECO, http://www.mineco.gob.es/portal/site/mineco/i-di), Projects No. BFU2013-44095-P and BFU2016-75609-P (cofunded with FEDER funds, EU).

Referencias:1. Valero, E.; Macia, H.; De la Fuente, I. M.; Hernandez, J.-A.; Gonzalez-Sanchez, M.-I.; Garcia-Carmona, F., Modeling the ascorbate-glutathione cycle in chloroplasts under light/dark conditions. BMC Systems Biology 2016, 10.2. González-Sánchez, M. I.; Valero, E.; Compton, R. G., Iodine mediated electrochemical detection of thiols in plant extracts using platinum screen-printed electrodes. Sensors and Actuators B-Chemical 2016, 236, 1-7.3. González-Sánchez, M. I.; Agrisuelas, J.; Valero, E.; Compton, R., Measurement of total antioxidant capacity by electrogenerated iodine at disposable screen printed electrodes. Electroanalysis, 2017; Vol. DOI: 10.1002/elan.201600797.

90


Cathode Host Materials for High-Performance Lithium-Sulfur Batteries.Guoxiu Wang.

Centre for Clean Energy Technology, School of Mathematical and Physical Sciences, University of Technology Sydney, Broadway, Sydney, NSW 2007, AustraliaE-mail: [email protected]

Lithium-sulfur batteries have been plagued for a long time due to low Coulombic efficiency, fast capacity loss, and poor high rate performance. Our focus is on the design and synthesis of various of innovative cathode host materials for lithium-sulfur batteries[1-5] including 3D hyperbranched hollow carbon nanorod architecture,[1] Poly(3,4-ethylene-dioxythiophene) coated multi-chambered micro/mesoporous carbon nanocubes,[2] three-dimensional metal carbide@me-soporous carbon hybrid architecture.[3] These sulfur nanocomposite cathodes deliver a high specific capacity and exhibit stable cycling performance. Particularly, poly(3,4-ethylenedioxythiophene) coated multi-chambered micro/mesoporous carbon nanocubes-sulfur cathodes delivered a high initial capacity of 1086 mAh/g at 1C rate and long cycling life up to 1000 cycles, and the electrodes also exhibited high rate capabilities of 842 mA h/g and 530 mA h/g after 1000 cycles at 5C and 10C, respectively. The superior electrochemical performances should be ascribed to the unique nano-architectures, which can effectively prevent the dissolution of polysulfides, decrease self-discharge, and confine the volume expansion during cycling. High capacity, excellent high-rate performance, and long cycle life endow the as-developed sulfur/carbon nanocomposites promising cathode materials for lithium-sulfur batteries.

References: [1] Shuangqiang Chen and Guoxiu Wang et al., Adv. Energy. Mater, 2014, 4, 13047.[2] Shuangqiang Chen and Guoxiu Wang et al., Nano Energy, 2015, 16, 268-280.[3] Weizhai Bao and Guoxiu Wang et al., Adv. Funct. Mater, 2016, Accepted.[4] Dawei Su, Michael Cortie and Guoxiu Wang, Adv. Energy. Mater, 2017, 7, 1602014.[5] Dawei Su, Michael Cortie and Guoxiu Wang et al., Adv. Mater, 2017 (in press).

ISE Session “Regional Student Meeting”

MASTER STUDENTS

Wednesday 5th July 14:30 - 17:00

92

Electrochemical reduction of CO2 to formate on nanoparticulated bismuth electrodes.Beatriz Ávila Bolívar.

Instituto de Electroquímica, Universidad de Alicante Apdo 99, 03080 Alicante, Spain. [email protected]

The electrochemical reduction of carbon dioxide (CO2) into liquid fuels offers a promising means of storing electricity in chemical form, which reduces the dependence on fossil fuels and mitigates the negative impact of CO2 emissions. An efficient catalyst must work at low overpotentials, reducing CO2 in the presence of water and selectively converting CO2 to desirable chemicals [1]. Very relevant efforts have been recently made about this important topic [2]. Some bulk metals such as Pb, In, Sn and Bi are known to catalyze the production of formate [2]. Interestingly Bi is not only non-toxic and cheap, but also stable due to its relatively positive electrode potential, which is important for an electrode working in aqueous solution [3]. In this contribution we study the electrochemical reduction of CO2 to formate on nanoparticulated Bi electro-des. Unsupported and carbon-supported Bi nanoparticles (about 10-12 nm) were prepared using an easy and fast metho-dology at room temperature. Once characterized by different physicochemical techniques (TEM, XPS and XRD), the samples were air-brushed on a carbon paper. The nanoparticulated Bi electrodes showed not only high selectivity towards the product of interest (formate/formic acid) but also an important stability.

Figure 1.Representative TEM image of the prepared Bi nanoparticles

References:1. Guilbault, G.G., Palleschi, G., Lubrano, G., 1995. Non-invasive biosensors in clinical analysis. Biosens. Bioelectron. 10, 379–392.2. Pérez, S., Fàbregas, E., 2012. Amperometric bienzymatic biosensor for l-lactate analysis in wine and beer samples. Analyst. 137, 3854.

Advisers/MentorsVicente Montiel Leguey, Instituto de Electroquímica, Universidad de Alicante, [email protected]é Solla Gullón, Instituto de Electroquímica, Universidad de Alicante, [email protected]

Acknowledgements:MINECO projects CTQ2013-48280-C3-3-R and CTQ2016-76231-C2-2-R (AEI/FEDER, UE).

93

Synthesis and development of new materials for lithium-ion batteries.Mateu Borràs Argemí.

Universidad Autónoma de Madrid, [email protected].

The development of advanced and efficient energy storage devices is a crucial issue in terms of advisable environmental and economic reasons nowadays. In this highly competitive and technical context, increasing efforts are being devoted to the research of new electrode materials for energy storage in the last years. Among these devices, lithium-ion batteries are considered the most attractive technology owing to their high power and energy density, long lifespan, low cost and environ-mental impact as well as their mature technology [1].

Focusing our interest in the anode materials, the most appealing options in terms of energy density are the use of lithium metal or lithium intercalable carbonaceous materials although both exhibit serious safety risks arisen from the lithium plating pheno-mena [2]. Alternatively, several transition metal oxides (CoO, CuO, FeO, NiO… have been proposed as anodes due to their high theoretical specific capacity (up to 1000 mAh/g) compared with the conventional carbon-based anodes (i.e. graphite exhibits almost 375 mAh/g) [3]. On the other hand, main drawbacks regarding these materials are related with high mechanical stress due to volume changes and particle agglomeration on continuous cycling processes what turn into loss of electrochemical performance. In order to overcome these difficulties regarding transition metal oxides, alternatives strategies have been explored; most of them are related with the use of different nanomorphologies [4].

The positive synergetic effect of use NiO with carbon material have demonstrated superior electrochemical performance [5]. NiO nanoparticles offer high theoretical specific capacity (≈720 mAh/g) and low cost, while the material offers high electrical conductivity and surface area, enough flexibility and high mechanical strength to adjust volume changes. Therefore, nickel oxide nanoparticles supported or anchored onto the carbon surface result into a hybrid material with significant potential as anode for lithium-ion batteries.

Here, we propose a new nickel oxide carbon supported and unsupported material as negative electrode where both strategies are combined. Nickel oxide nanoparticles and carbon supported nanoparticles (on Vulcan XC73R) were synthetized by a simple modified impregnation method. The unsupported synthetized NiO nanoparticles and NiO commercial nanoparticles mixed with carbon (Super P carbon black) in three different NiO:C ratios (80:20, 50:50 and 20:80) were tested as negative electrode obtaining the best results with the home-made NiO nanoparticles and the 20:80 NiO:C rate. (NiO20:80). The NiO20:80 and the carbon supported NiO nanoparticles were compared with only Super P and Vulcan respectively as anode material. The results show that the presence of the NiO nanoparticle improves significantly the performance of the carbon materials.

References:1. Z. Fan, J. Yan, T. Wei, L. Zhi, G. Ning, T. Li and F. Wei, Adv. Funct. Mater., 2011, 21, 2366-2375.2. Li, Z.; Huang, J.; Yann Liaw, B.; Metzler, V.; Zhang, J.Power Sources 2014, 254, 168.3. P.L. Taberna et al. Nature Mat. 5, 2006, 567-573.4. Z. H. Li et al. Electrochim. Acta 55, 2010, 8981-8985.5. X. Yang et al J. Colloid and Interface. Sci. 469, 2016, 287-295.

Advisers/Mentors:Pilar Ocón Esteban (Universidad Autónoma de Madrid), [email protected]. Juan Carlos Pérez Flores (Universidad CEU San Pablo), [email protected].

94

Characterization of metal-solution interface by Pulse Voltammetry.Montse Buaki Sogó.

Departamento de Química, Laboratorio de Electroquímica. Universitat Politècnica de València, Camino de Vera s/n 46020 [email protected].

In the latest years [1] capacity’s study of some metals such as Platinum, used as a electrode’s surface have been relevant. Knowing electrode’s capacity is important because let it know features as double layer, its structure, the molecule’s arrange-ment and control reactions that happens: metal’s deposition and solution, corrosion, electrocatalysis, film’s formation and electro-organic synthesis.[2]

Few years ago, capacity’s determination, both Gold and Platinum, was made by technics such as Cyclic Voltammetry, Electrochemical Impedance Spectroscopy and Impedance’s Bridges. Advantages of applying Pulse Voltammetry (Step’s Potential Voltammetry) are: it’s a novel technic, allows to gather a lot of information passing a few charge, it doesn’t polarized the samples so continuous assays can be made without waiting polarization disappears, experiment’s time is short and pulse can be shortened as much as be needed or desired by analyst.[3]

In this study Platinum’s and Gold’s capacity determination was carried out, applying step’s potential of +50mV; using KNO3 and KCl solutions in different concentrations. Data obtained were analyzed considering that an electrochemical system can be modeled using an electric equivalent circuit and its mathematic equations. Three electric equivalent models were chosen within its equations, its electric performance was studied previously; system’s total capacities were calculated and then compared with obtained capacities from charge’s curves.

Analyzed Gold and Platinum will be electrochemical sensors that are included into an electronic tongue [4], used device nowadays for a daily control’s quality of a lot of chemical processes.

References:1. W.D. Robertson. Journal of Electrochemical Society. 1953, vol100. 194 – 201.2. Bockris, Reddy, Gamboa-Aldeco. Modern Electrochemistry Vol.2A. Second Edition, Kluwer Academic Pub-lishers, New York. 20003. Román Bataller, José Manuel Gandía, Eduardo García-Breijo, Miguel Alcañiz, Juan Soto. Electrochemica Acta. 2015. Vol 153. 263 – 272. 4. Inmaculada Campos, Miguel Alcañiz, Rafael Masot, Juan Soto, Ramón Martinez-Mañez, José-Luis Vivancos, Luis Gil. Sensors and Actuators. 2012. Vol 161. 556 – 563.

Advisers/MentorsD.Juan Soto Camino, Departamento de Química - Universitat Politècnica de València, [email protected] Montiel Leguey, Departamento de Química Física – Universitat d’ Alacant, [email protected].

95

Electrosynthesis of nanostructures for feasible biomedical applications.Anna Caparrós García.

Grup d’Electrodeposició de Capes Primes i Nanoestructures (Ge-CPN), Institut de Nanociència i Nanotecnologia (IN2UB), Departament de Ciència dels Materials i Química Física, Facultat de Química, Universitat de Barcelona, C/ Martí i Franqués, 1, 08028, Barcelona. ([email protected])

The magnetic nanoparticles (MNPs) are a type of particles of nanometric size frequently containing Fe, Co or Ni or their oxides. Their magnetic properties are depending on the chemical composition, crystal structure, and shape and dimension of the nanostructures. In MNPs’ field, the most used material is iron’s oxide, being the nanostructures synthesized by means of different chemical methods [1]. However, electrochemical methods can be also used to synthetize nanostructures of iron and/or iron oxides, in which the control of the nanostructures size could be performed by adjusting the current or the potential applied and the deposition charge during an electrodeposition process. In the project herein, iron/iron oxide nanostructures are synthesized by electrochemical procedures in order to explore their feasible applicability on biomedicine, taking advantage of their great biocompatibility into cellular media and the ability of cells to degrade this material. To obtain them, a bath contai-ning FeCl2 in acidic aqueous medium has been used and galvanostatic, potentiostatic and pulsed methods have been tested to produce them, allowing comparison among all methods to find the best pathway to create them. Electrochemical conditions have been selected to directly produce Fe/Fe oxides nanostructures, which have been characterized by means of magnetic hysteresis curves, X-Ray diffraction and Scanning Electron Microscopy, in order to determine the composition, structure, size, morphology and magnetic properties of the obtained material in the synthesis process. Finally, bovine serum albumin (BSA) has been used to functionalize them, and ferrocyanide / ferricyanide probe has been tested to verify the correct functionalization of the nanostructures with the aim of examine possible applications on biomedical field.

SEM image of iron/iron oxide nanoparticles at A) x20 magnification (scale: 1µm); B) x50 magnification (scale: 100 nm).

References:1. Wu, A.; Ou, P.; Zeng, L. Biomedical Applications of Magnetic Nanoparticles. Nano 2010, 5 (5), 245–270 DOI: 10.1142/S1793292010002165.

Advisers/Mentors:Dra. Elisa Vallés, Grup d’Electrodeposició de Capes Primes i Nanoestructures (Ge-CPN), Institut de Nanociència i Nanotecnologia (IN2UB), Departament de Ciència dels Materials i Química Física, Facultat de Química, Universitat de Barcelona ([email protected]).

A B

96

Characterization of self-assembled monolayers of oligoethyleneglycol (OEG) on gold surfaces.Miriam Chávez Peraza.

Instituto de Química Fina y Nanoquímica, Depto Química Física y T. A. Universidad de Córdoba, Campus Rabanales, Ed. Marie Curie 2ª Planta, E-14014 Córdoba, Españ[email protected]

Self-assembled monolayers (SAMs) are molecular assemblies formed by spontaneous adsorption of molecules on surfaces. These systems are organized into more or less large ordered domains and can be considered as the most elementary forms of thin films of organic material at nanometric scale.[1]

There are many experimental factors that can affect the structure of the resulting SAM and its rate of formation (solvent, temperature, concentration of adsorbate, immersion time, etc.), however, most experimental conditions for the preparation of SAMs yield organic interfaces with reproducible and desired functional behaviours. Usually, these characteristics are acceptable for some applications but when the studies are focused on BioNanoMedicine,[2,3] the modified materials need to be biocompatible. Thus, an understanding of how to minimize defects in the SAMs and maximize order in these systems is necessary.

In this work, the surface functionalization is based on thiol chemistry groups derived from ethylene glycol oligomers (OEGn). These compounds have found great applicability because of its ability to avoid protein adsorption. We have studied the SAMs formed by HS-OEGn of different polymerization degree (n = 6, 18 and 45) on gold substrates (either poly-oriented or (111) single crystal).

Multiple techniques such as electrochemical (cyclic voltammetry and impedance spectroscopy), spectroscopic (FT-IRRAS and XPS) and Contact Angle measurements have been used in the characterization of the formed SAMs.

References:(1) Love, J. C.; Estroff, L. A.; Kriebel, J. K.; Nuzzo, R. G.; Whitesides, G. M. Self-Assembled Monolayers of Thiolates on Metals as a Form of Nanotechnology. Chem. Rev. 2005, 105, 1103-1169.(2) Yao, J.; Yang, M.; Duan, Y. Chemistry, Biology, and Medicine of Fluorescent Nanomaterials and Related Systems: New Insights into Biosensing, Bioimaging, Genomics, Diagnostics, and Therapy. Chem. Rev. 2014, 114, 6130-6178.(3) Walkey, C. D.; Olsen, J. B.; Guo, H.; Emili, A.; Chan, W. C. W. Nanoparticle Size and Surface Chemistry Determine Serum Protein Adsorption and Macrophage Uptake. J.Am. Chem. Soc. 2012, 134, 2139-2147.

Advisers/Mentors:María Teresa Pineda Rodríguez, Universidad de Córdoba. E-mail:[email protected]

Acknowledgements:Ministerio de Economía y Competitividad (MINECO) (Proyectos CTQ2014-60227-R and CTQ-2015-71955-REDT Red de Excelencia Sensores y Biosensores Electroquímicos), Junta de Andalucía (P10-FQM-6408) y Universidad de Córdoba.

97

Study of the Ethanol Electro-oxidation for the application of fuel cells.Álvaro De la Aldea Martín.

Universidad Autónoma de Madrid “Master en Electroquímica”, Calle Sopetrán nº 6 5ºD Madrid. [email protected]

This is a study of the Ethanol Electro-oxidation for its application to fuel cells (DEFC “Direct Ethanol Fuel Cells”). Ethanol Electro-oxidation offers different advantages respect to other devices, specifically to the use of Methanol (DMFC "Direct Metha-nol Fuel Cells"):

- Ethanol has low toxicity. - Ethanol is an attractive alternative to methanol because it comes with a supply chain that's already in place. Ethanol also

remains the easier fuel to work with for widespread use by consumers.- Ethanol is a hydrogen-rich liquid and it has a higher specific energy against Methanol. - Ethanol can be obtained from biomass, also can be get from fermentation process.- From the point of view environmental pollution, it can be obtained by sustainable ways compared with fossils fuels.- The storage cost would be lower than the Hydrogen for fuel cells.

Fuel cells require a catalyst at the electrodes for the activation of the redox reactions, which is normally composed of Pt as the active component. The object of this study is the physicochemical and electrochemical characterization of electrocatalysts for DEFC, and the analysis of the intermediate reactions that take place in the process of oxidation of ethanol using in situ Fourier Transform infrared spectroscopy (FTIR), allowing the analysis of the parameters that influence the decreasing of the catalysts performance by poisoning of the catalytic surface during the ethanol electroxidation.

Advisers/Mentors:Miguel A. Peña, Institute of Catalysis and Petrochemistry, CSIC, [email protected].

98

Design and Fabrication of low-powered Electrochromic Devices.Ghizlane El Harrak Benaicha.

[email protected]

Electrochromic devices are electrochemical devices which undergo colour changes when a sufficient electrical potential is applied. Typically, electrochromic devices present a two-electrode configuration, where at least one electrode is optically transparent and the electrodes are separated by a layer of supporting electrolyte. The physical properties of these devices, such as optical and response time, are predominantly dictated by the electrochromic materials used in their construction [1]. Here we developed an electrochromic display device featuring an interdigitated electrode configuration, wherein the electrodes are side-by-side rather than face-to-face. All the materials involved have been developed during the project make these devices compatible with screen printing and roll-to-roll production. This material development work has focused on the electrochromic materials, but also suitable gel electrolytes. The final devices operate on ±1.5V, and show good reversibi-lity and stability. The operation and characteristics of this device are discussed. We present the fabrication and their charac-terization using cyclic voltammetry, chronoamperometry, spectro-electrochemistry and UV–vis spectroscopy.

References:1. P.M.S. Monk, R.J. Mortimer, D.R. Roosseinsky, Electrochromism: Fundamentals and Applications, VCH, 1995.

Advisers/Mentors:Javier del Campo García ([email protected]) / Gonzalo Guirado López ([email protected]) Iluminada Gallardo García ([email protected])

99

Spectro-electro-gravimetry of poly(o-toluidine).Amparo Ferrer Vilanova.

Universitat de València, Departament de Química Física, [email protected].

Conducting polymers are being extensively studied due to its interesting applications in various technologically important devices such as batteries, smart windows, smart membranes, artificial muscles, nervous interfaces, or drug delivery systems. Structural changes such as conformational movements of polymeric chains during the electrochemical reactions take place with the exchan-ge of ions and solvent between the film and the solution [1]. One of the most interesting features of conducting polymers occurs when these materials are electrochemically maintained for some time in the reduced state (ageing). In this work, the relaxation process induced by cyclic voltammetry of aged poly(o-toluidine) films (POT) was investigated by implemented electrochemical, gravimetric and Vis-NIR spectroscopic techniques. The information provided by these techniques allows the evolution of exchange of species and electrochromic centers induced by electrochemical relaxation to be studied [2,3]. The exchange of protons and anions are associated to the formation of two different polaronic centers in POT films. Ageing time affect the electrochemical, electrochromic and electrogravimetric response of POT.

References:1. T.F. Otero, J.G. Martinez, Structural and Biomimetic Chemical Kinetics: Kinetic Magnitudes Include Structural Information, Adv. Funct. Mater. 23 (2013) 404–416.2. J. Agrisuelas, C. Gabrielli, J.J. García-Jareño, H. Perrot, F. Vicente, Kinetic and Mechanistic Aspects of a Poly(o-toluidine)-Modified Gold Electrode. 1. Simultaneous Cyclic Spectroelectrochemistry and Electrogravimetry Studies in H2SO4 Solutions, J. Phys. Chem. C. 116 (2012) 15620–15629.3. J. Agrisuelas, C. Gabrielli, J.J. García-Jareño, H. Perrot, F. Vicente, Effects of anions size on the redox behavior of poly(o-toluidine) in acid solutions. An in situ vis-NIR cyclic spectroelectrogravimetry study, Electrochimica Acta. 125 (2014) 83–93.

Advisers/Mentors:Teresa Pineda Rodríguez. Universidad de Córdoba, Departamento de Química Física y Termodinámica Aplicada. [email protected] Juan García Jareño, Universitat de València, Departament de Química Física. [email protected].

100

Effect of impedimetric sensor modification strategies on its response.Dmitry Galyamin.

BioMEMS Group, Institute of Microelectronics of Barcelona (IMB-CNM, CSIC), Campus Universitat Autònoma de Barcelona, [email protected]

The use of impedimetric biosensors based on interdigitated electrode arrays (IDEA) for biochemical applications has gained increased interest during the last two decades [1]. Different strategies may be applied for constructing an affinity biosensor based on an IDEA transducer. However, no thorough study was performed to find how sensor functionalization with probe molecules (e.g. antibody, single strand DNA) may affect the sensitivity.

Earlier in model calculations [2] it has been demonstra-ted that the sensitivity to surface reactions of an IDEA becomes higher in the row: i) only electrodes are modified; ii) only enter-electrode spacing is modified; iii) all the surface is modified. Nevertheless, there is no experimental results that confirm the effect of modifica-tion type on the sensitivity.

In this work we have tried to demonstrate experimenta-lly how three different methods of chemical modifica-tions affect the sensor parameters. Two types of IDEA sensors of the same geometry were used. The first is an IDEA sensor with gold electrodes on a SiO2 substrate. The gold is chemically modified using cisteamine (thiol) and electrode spacing (SiO2) with (3-aminopropil)-trime-toxisilane (APTMS) - a silane with the same carbon chain as cisteine. The second type of the sensor is made with TaSi2 electrodes on silicon oxide. This sensor design permits modification of the entire surface (electrodes and enter electrode space) with APTMS as TaSi2 is covered with a native mixed oxide.

Preliminary experiments by X-ray photoelectron spectroscopy demonstrated that non-specific adsorption of APTMS takes place on gold electrodes. To eliminate non-specific bindings three ways of electrochemical cleaning methods were studied: a- sulphuric acid potential cycling; b- nitrate potassium potential cycling and c- chronoamperometric method. For this purpose, amperometric gold electrodes were applied.

References:1. Brosel-Oliu, S., Galyamin, D., Abramova, N., Muñoz-Pascual, F.-X., Bratov, A., Impedimetric label-free sensor for specific bacteria endotoxin detection by surface charge registration. Electrochimica Acta. DOI: 10.1016/j.electacta.2017.05.0602. Guimerà, A., Gabriel, G., Prats-Alfonso, E., Abramova, N., Bratov, A., Villa, R., 2015. Effect of surface conductivity on the sensitivity of interdigitated impedimetric sensors and their design considerations. Sensors and Actuators B: Chemical 207, Part B, 1010-1018.

Advisers/Mentors:Andrei Bratov1, [email protected] Abramova1, [email protected] Gallardo2, [email protected] BioMEMS Group, Institute of Microelectronics of Barcelona (IMB-CNM, CSIC), Campus UAB 2 Chemical-physics department, Universitat Autònoma de Barcelona

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Adsorption of anion citrate onto well-defined surface electrodes.José María Gisbert González.

Master Degree Student, Institute of Electrochemistry of the Universidad de Alicante, [email protected]

Most of the electrochemistry reactions of interests are sensitive to the surface structure of catalyzers. For this reason, if we want to optimize the reactivity, is very important to use nanoparticles with well-defined surfaces. For this purposes different-shaped nanoparticles have being widely used. During the synthesis, adsorption of surfactant controls the shape by guiding the growing direction. Almost all of the synthesis processes are based on empirical results, ignoring how the surfactants act on them.

The present study try to clarify the surfactant role on synthesis processes. To do so, we have studied the adsorption of citrate on Pt(111) single crystal electrode at different pH in solutions of citric acid with an excess of an inert electrolyte (HClO4). Pt(100) and Pt(110) have been used at the same conditions in order to compare their results with those obtained for the Pt (111). The total charge densities were calculated by integration of cyclic voltammetry curves. A complete thermodynamic analysis[1, 2]using the electrode potential and the charge as independent variables has been performedfor the Pt(111) electrode to calculated the Gibbs excess of citrate on Pt(111) and electrosorption valencies.

References:[1] J. Mostany, E. Herrero, J.M. Feliu, J. Lipkowski, Thermodynamic studies of anion adsorption at stepped platinum(hkl) electrode surfaces in sulfuric acid solutions, J. Phys. Chem. B, 106 (2002) 12787-12796.[2] E. Herrero, J. Mostany, J.M. Feliu, J. Lipkowski, Thermodynamic studies of anion adsorption at the Pt(111) electrode surface in sulfuric acid solutions, J. Electroanal. Chem., 534 (2002) 79-89.

Advisers/Mentors:Enrique Herrero Rodríguez, University professor, [email protected].

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Surfaces with switchable catalytic activity in films by in-version of the ferroelectric polarization of the substrate.Cecilia Hernández Guerrero.

ICMAB-CSIC, 08193 Bellaterra, Cerdanyola del Valles, (Barcelona) SPAIN, [email protected]

Hydrogen with its unique properties of high-energy efficiency, easy storage, and freedom from pollution has been conside-red as a promising alternative to the conventional sources of energy. One of the most promising technologies capable of providing high energy yield without pollutant byproducts is the photocatalytic water splitting (PWS) using sunlight. Titania is of interest among others for the photovoltaic conversion of light to electricity [1,2]. However, TiO2 materials suffer from two major drawbacks. One of them is the fast charge carrier recombination (electron-hole pairs), which results in the release of unproductive energy. Another one is the inability to harvest visible light, since TiO2 can only be excited by UV light due to its wide band gap of 3.0–3.2 eV, which only covers 5% of the solar spectrum [3,4]. A promising strategy to increase the visible light activity of titania, as proposed in this project, takes into account that titania supported on a visible light absorbing core of a ferroelectric material shows enhanced visible light photoactivity [5]. This is due to the dipolar field of the ferroelectric that can influence the motion of charge carriers in the catalytic coating.

In this work we focus on the preparation of TiO2 thin films grown on BaTiO3(001) films oriented on SrTiO3(001) by PLD. Under our conditions, BaTiO3 seems to grow initially with a layer-by-layer growth mechanism. In order to investigate the surface morphology, crystalline orientation, microstructure, and film/substrate interface of the films, different characteriza-tion techniques, i.e.: x-ray diffraction (XRD), atomic force microscopy (AFM) and high-resolution transmission electron microscopy (HRTEM) were applied. Ferroelectricity of the BaTiO3 films was proved by electrical measurements performed on Ag/BaTiO3 /SRO heterostructures.

Figure 1 Figura 1.Reciprocal space images at different L-values corresponding to the (1,0,L) reflection. Peak numbers 1, 2 ,3 and 4 correspond to TiO2 (101), BTO (101), STO (101) and TiO2 (103) reflections indexed according to their respective

References:1. O’Regan, B. & Grätzel, Nature 353 (1991) 737–740.2. Hussain, H. et al. Nat. Mater. (2016). doi:10.1038/NMAT47933. Breckenridge, R. G. & Hosler, W. R.,Phys. Rev. 91 (1953) 793–802.4. Pascual, J. et al., Phys. Rev. B 18 (1978) 5606–5614.5. Gao, B. et al., Appl. Catal. B Environ. 83 (2008) 202–207.

Advisers/Mentors:Xavier Torrelles, PhD ICMAB, [email protected] Gallardo García, UAB, [email protected]

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Spectra - electro - gravimetry of Prussian Blue.Sara Lozano Zarzo.

Laboratory of Electrochemistry. University of Valencia, C/ Dr. Moliner, 50, 46100 – Burjassot (Spain). [email protected]

The development of treatment processes for the fast and efficient recovery of radioelements like Cs+, are currently being studied by many researchers [1,2].

In this work, insertion of cesium through Prussian Blue films is studied by means Spectra-electro-gravimetric techniques. The measurement of current, mass and absorbance magnitudes allows Everitt’s Salt system for PB films with different degree of crystallinity (Figure 1). The structural differences between amorphous PB films and crystalline PB films in CsCl solutions are put in evidence by means these in situ coupled techniques.

Figure 1. Current response of the first cycle of three PB films deposited on Au electrode (S= 28 mm2) with different degree of crystallinity during the stabilization process in 0.5M CsCl (pH 2.9). Reference electrode Ag|AgCl|KCl; v= 20mV·s-1; T= 296K.

References:1. The correlation between electrochemical impedance spectra and voltammograms of PB films in aqueous NH4Cl and CsCl. J. Garcia-Jareño, J. Navarro-Laboulais, A. Sanmatias, F. Vicen-te, Electrochim. Acta, 43 (1998) 1045-1052.2. Interfacial Role of Cesium in Prussian Blue Films. R. Catalan, J. Agrisuelas, A. Cuenca, J.J. Garcia-Jareno, A.F. Roig, F. Vicente, Interfacial Role of Cesium in Prussian Blue Films, J. Electrochem. Soc. 162 (2015) H727-H733

Advisers/Mentors:Francisco Vicente Pedrós, University of Valencia, [email protected] Pineda Rodríguez, University of Córdoba, [email protected].

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104

On the electrochemical response of chlorinated cytosine at carbon based electrodes as a novel marker in epigenetic.Andrés Noel Martín Gómez.

Institute of Electrochemistry, Faculty of Science, University of Alicante. Alicante, 03080, Spain.

Many of the genetic mutations and epigenetic modifications in DNA are strongly linked to the triggering and development of pathophysiological disorders or cancer diseases. Oxidation of nucleic bases such as the formation of oxoguanine or oxoadenine, and methylation of guanine and cytosine are clear examples of the most relevant epigenetic modifications in DNA. More particularly, hypermethylation of DNA has been demonstrated to be normally associated with some diseases [1], including carcinomas, leukemia, and lung cancer, among many others. Even though others epigenetic modifications such as hydroxymethylation or carboxylation of cytosines have emerged recently as novel biomarkers associated with pathologi-cal dysfunctions or diseases, the chlorination of DNA, particularly, the formation of chlorocytosine, has attracted the resear-chers nowadays. In this regard, the participation of radical species that mediates via inflammatory responses of cellular tissues can give rise to the formation of halocytosine such as chlorocytosine (Cl-Cyt) [2]

The aim of this work is to study the electrochemical behaviour of Cl-Cyt on different carbon materials such as glassy carbon, graphite or boron doped diamond electrodes using cyclic voltamperometry (CV) and pulse techniques like square wave voltammetry (SWV). First, the synthesis of Cl-Cyt was performed following the procedure described elsewhere [3] and NMR studies determined the high purity of the halogenated nucleic base. The electrochemical response of Cl-Cyt was explored as a function of pH solution by using CV and SWV. After pH optimization, the electrooxidation of Cl-Cyt was explored with concentration and as a function of the anodic or cathodic conditioning of the electrode surfaces. The effect of the haloge-nated atom (X=F, Br) located at the position C-5 of the cytosine entity was also examined on the electrooxidation peak at different carbon materials. Finally, the simultaneous determination of Cl-Cyt in the presence of other nucleic bases, such as guanine, adenine, thymine and cytosine, was also addressed in this work for analytical sensing applications.

References:[1] H. Tao, J.-J. Yang, K.-H. Shi, Z.-Y. Deng, and J. Li, “DNA methylation in cardiac fibrosis: new advances and perspectives.,” Toxicology, vol. 323, pp. 125–9, 2014.[2] B. I. Fedeles et al., “Intrinsic mutagenic properties of 5-chlorocytosine: A mechanistic connection between chronic inflammation and cancer,” Proc. Natl. Acad. Sci., vol. 112, pp. E4571–E4580, 2015.[3] J. Jansa, A. Lycka, A. Ruzicka, M. Grepl, and J. Vanecek, “Synthesis, structure and rearrangement of iodinated imidazo[1,2-c]pyrimidine-5(6H)-ones derived from cytosine,” Tetrahedron, vol. 71, pp. 27–36, 2015.

Advisers/Mentors:Jesús Iniesta Valcárcel, Instituto de Electroquímica, Universidad de Alicante, 03080 Alicante, Spain, [email protected]

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Electrocatalytic hydrogenation of Benzophenone.Cristina Mozo Mulero.

Instituto de Electroquímica, Universidad de Alicante, Apartado 99, 03080 Alicante, Spain [email protected]

Electrocatalytic hydrogenation provides an alternative for hydrogenation of organic compounds under room temperature and atmospheric pressure instead of catalytic hydrogenation conditions (high temperature and pressure) [1]. As It is known, PEM technology is used in fuel cell processes but, obviously, this philosophy could be applied to any other electrochemical process. Therefore, a Polymer Electrolyte Membrane Electrochemical Reactor (PEMER) has been defined [2]. The advantages of this type of reactor are evident: the use of nanostructured electrocatalysts and polymeric solid electrolytes and, moreover, cathode-anode gap lessening. Electrocatalytic hydrogenation process depends mainly on factors such as the chosen electrocatalysts or the used current density among others. In the case of aromatic ketone electrocatalytic hydrogenation, Pd is widely used as electrocatalyst due to its high selectivity in conversion to alcohol [1].

In this research, the electrocatalytic hydrogenation of benzophenone using a PEMER have been carried out. Cathodes were manufactured using Pd/C 30 wt% (Figure 1a) as electrocatalyst and catalytic loadings (LPd) of 0.2 and 0.02 mg Pd cm-2 (Figure 1b). Starting solutions of 0.5 M benzophenone and 0.1 M H2SO4 were fed to cathodic compartment with a flow rate of 12 mL min-1. Moreover, hydrogen oxidation reaction was chosen as anodic process using a gas diffusion commercial electrode as anode. Nafion 117 was used as solid polymer electrolyte. Current densities of 10, 15 and 20 mA cm-2 were tested and the highest fractio-nal conversion (XR), around 30%, was obtained for the lowest tested current density. In this case, diphenylmethanol selectivity over 90% was obtained (Figure 1c).

Figure 1. (a) Transmission electron micrography of Pd/C 30 wt%; (b) Scanning electron micrography of cathode (LPd=0.02 mg Pd cm-2); (c) Fractional conversion (XR) and product yields (η) vs charge passed.

References:1. C. M. Cirtiu, A. Brisach-Wittmeyer y H. Ménard, «Electrocatalysis over Pd catalysts: A very efficient alternative to catalytic hydrogenation of cyclohexanone» Journal of Catalysis, vol. 245, pp. 191-197, 2007.2. A. Sáez, V. García-García, J. Solla-Gullón, A. Aldaz y V. Montiel, «Electrocatalytic hydrogenation of acetophenone using a Polymer Electrolyte Membrane Electrochemical Reactor» Electrochimica Acta, pp. 69-74, 2013.

Advisers/Mentors:Alfonso Sáez Fernández, Instituto de Electroquímica, Universidad de Alicante, Apartado 99, 03080 Alicante, Spain, [email protected] Montiel Leguey, Instituto de Electroquímica, Universidad de Alicante, Apartado 99, 03080 Alicante, Spain, [email protected].

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Electrochemical preparation of cobalt and nickel nanostructures from DES. Yi Na.

Departament de Ciència de Materials i Química Física, Universitat de Barcelona. [email protected]

The electrodeposition of nickel and cobalt attracted a great interest in view of their multiple applications, related, in the past, with the production of decorative or corrosion-resistant materials. At present, these metals have found their place as supported nanomaterials in the production of sensors, heterogeneous catalyst, supercapacitors, magneto-optic recording devices, among others. The preparation of the nanomaterials by electrodeposition offers several advantages since it permits the growth of the materials directly on the support without post-treatments, using a simple equipment.

Sulphate solutions have been the preferred electrolytic baths to electrodeposit cobalt and nickel nanoclusters onto different substrata. However, the use of these aqueous baths, especially for nickel electrodeposition, has several drawbacks, nickel and cobalt reduce at highly negative overpotentials and simultaneously induce the reduction of proton species. Hence, without a pH control, non-soluble nickel hydroxides could form, making the reproducibility of the process complicated.

Room Temperature Ionic Liquids (RTILs) have been considered as interesting alternative to aqueous electrolytes but they require to be handled under controlled conditions. In this context, over the last decade, deep eutectic solvents (DESs), a novel type of stable electrolytes, have generated interest. The preparation of DESs is easy and have low toxicity and conve-nient price. Moreover, DESs are especially interesting because of their ability to stabilize nanoclusters and to facilitate nanoparticle self-assembly.

This work is devoted to the study of nickel and cobalt deposition processes in a DES medium, a eutectic mixture of choline chloride and urea. Electrochemical techniques were used to analyze the deposition processes. Deposits were prepared at different conditions and morphologically characterized by SEM. The results indicate that the morphology could be contro-lled by modification of electrodeposition conditions. Nickel and cobalt nanostructures were prepared, for which less structuration was observed for nickel.

Nickel and cobalt deposition processes in aqueous chloride medium were analyzed for comparison.

Figure 1. SEM images of a) cobalt and b) nickel

Advisers/Mentors:Dra. Elvira Gómez Valentín, Departament de Ciència de Materials i Química Física, Universitat de Barcelona, [email protected]

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107

Galvanostatic electrolysis of aqueous solutions of nitrate and ammonium.Roger Oriol López.

Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, [email protected]

Electrochemical denitrification is one of the most promising methods for the removal of nitrate from groundwater due to its ability to transform the total nitrogen into innocuous N2 triggered by cathodic reduction. The degradation of organic pollutants and secondary by-products can simultaneously occur by anodic oxidation, thus allowing the gradual mineralization of solutions. The major advantages over other techniques such as electrocoagulation or bioelectrochemistry include: waste minimization, inexpen-sive infrastructure and relatively low maintenance required. Due to the complex chemistry of nitrogen, with multiple secondary products potentially formed by electrodenitrification (e.g., N2, hydrazine, hydroxylamines, nitrite, ammonia, NxOy, chloramines), it is crucial to address a thorough optimization, aiming to attain the total removal of nitrate but avoiding the production of secondary pollutants (i.e., maximizing the amount of N2 generated). Being ammonium (ammonia at alkaline pH) the most common primary product, it is necessary to find the most favourable conditions for its conversion to N2 via in situ anodic oxidation.

The main goal of the present work is to study the effect of different cathodes (Fe, Cu, Ti, graphite and stainless steel) on nitrate removal upon galvanostatic electrolysis in synthetic water matrices, at constant temperature, conductivity and pH. In unreactive media, ion chromatography has been employed to determine the concentration of nitrate, nitrite and ammonium. The formation of hydrazine and hydroxylamines has also been studied. In chlorinated medium, active chlorine, chlorate, perchlorate and chlora-mines concentration has been evaluated as well. In all cases, the evolution of total nitrogen has been assessed using a TOC analyzer. Most of the tests have been performed in undivided cells, although a divided cell has also been used for comparison. Once optimized the setup, the effect of the cathode area, current density, supporting electrolyte, initial nitrate content and anode nature (i.e., DSA® and BDD) has been investigated, yielding a large percentage of nitrate removal in some cases. As a first approach, all experiments have been carried out in the absence of organic matter, thus leaving the door open for further studies. Some insight is also given into the ability of Fenton-based electrochemical processes to transform nitrate ions.

Acknowledgments:Financial support from project CTQ2016-78616-R (AEI/FEDER, EU), as well as from excellence network E3TECH under project CTQ2015-71650-RDT (MINECO, Spain) is acknowledged.

Advisers/Mentors:Dr. Ignacio Sirés Sadornil, Universitat de Barcelona, [email protected].

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Energy storage devices based on graphene. Influence of the structure on its capacitive and faradal signal. Pilar Sánchez Peña.

Instituto Catalán de Nanociencia y Nanotecnología, Campus de la UAB, Sv. De Serragalliners, s/n, 08193, Bellaterra, Barcelona. [email protected]

Energy storage is an increasingly important element within a sustainable model of production, management and use of energy.

To this end, graphene is particularly promising because, in comparison with other materials, it has a very large active surface area per unit mass, allowing faster loading speeds, and it has valuable intrinsic properties like high electrical and thermal conductivity. Due to these attributes, graphene is now being widely studied particularly in the field of energy storage.

The present research aims to study different types of graphene and its derivatives for use as advanced materials in energy storage devices, from batteries to supercapacitors or hybrid devices. The materials studied were: graphene prepared by electrochemical exfoliation, reduced graphene oxide, graphene obtained through a tribological exfoliation process (one sample prepared in our laboratories and another one commercial), and, finally, graphite for comparison. The various graphene materials were synthesised to fabricate solid electrodes for electrochemical energy storage with the aim of determining correlations between the materials using physicochemical characterizations and various electrochemical analysis.

The materials were characterised as follows: crystallinity by X-ray diffraction; microstructure by scanning electron microsco-py and transmission electron microscopy; Raman spectroscopy; elemental composition by determination of carbon, oxygen and hydrogen by elemental analysis; and an extensive electrochemical characterisation by cyclic voltammetry, chronopoten-tiometry for charge-discharge cycles and electrochemistry impedance spectroscopy.

Most of the materials studied led to electrodes with a moderate storage capacity, studied at different rates. Besides, the possible intercalation of lithium was studied by cyclic voltamperometry. Electrochemical impedance spectroscopy was used to estimate the resistance of the elements that constitute a cell. Finally, a comparative study of the electrochemical energy storage properties of the materials was made.

References:1. Dubal, D. P. et al. "Hybrid Energy Storage: The Merging Of Battery And Supercapacitor Chemistries". Chem. Soc. Rev. 44.7 (2015): 1777-1790. 2. Kim, Haegyeom et al. "All-Graphene-Battery: Bridging The Gap Between Supercapacitors And Lithium Ion Batteries". Scientific Reports 4.1 (2014): n. pag. Web.3. S. Guevara, J. Gabriela, P. Gómez - Romero, V. Ruiz, “Materiales híbridos basados en nanocarbones y polioxometalatos para aplicación como electrodos en supercondensadores con mecanismo dual de almacenamiento de energía”, Universitat Autònoma de Barcelona, 2015.

Advisers/Mentors:Dra. Elvira Gómez Valentín, Departament de Ciència de Materials i Química Física, Universitat de Barcelona, [email protected]

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Solution processable organic perovskite solar cells applying semiconductor oxides as barrier layers.Óscar Sánchez Sierras.

Instituto Catalán de Nanociencia y Nanotecnologia, UAB, [email protected]

Highly efficient thin film solar cells like Dye sensitized, Organic and, more recently, Perovskite solar cells, are now a reality with power conversion efficiencies between 12% and 22%. The photoactive layer in these devices generally consists of nanoscopic phase separation between semiconductors (oxide nanoparticles, organic polymers, dyes, halide perovskites, etc.) to convert sunlight into electricity. The operational principle involves a complex sequence of events, starting with the absorption of light, followed by creation, separation, transport, and collection of charges.

In this thesis, we study lifetime and stability of inverted configuration organic solar cells with a mixture of poly (3-hexylthiophe-ne-2, 5-diyl) (P3HT) and [6, 6] Phenyl-C61-butyric acid methyl ester (PCBM) as active layer. We also focus on the benefits of using semiconductor oxides, such as zinc oxide (ZnO) as electron transport layer and vanadium pentoxide (V2O5) as hole transport layer, since these bring more stability to the solar cells than organic semiconductors. The devices are fabricated by the spin-coating technique, which is widely employed for the highly reproducible fabrication of thin film coatings. We will show the optimization of the OPV devices, their characterization and lifetime stability studies. Data was collected through indoor and outdoor tests, in accordance with ISOS protocols ISOS-L-1 and ISOS-O-2 respectively. Finally, we present upgrades and optimized procedures implemented to in-house outdoor measurement software.

References:1. Terán-Escobar, G., Pampel, J., Caicedo, J.M., Lira-Cantú, M. (2013) Energy and Environmental Science, 6 (10), pp. 3088-3098. 2. Teran-Escobar, G., et al. (2012) Physical Chemistry Chemical Physics, 14 (33), pp. 11824-11845. 3. Rösch, R., et.al. (2012) Energy and Environmental Science, 5 (4), pp. 6521-6540.

Advisers/Mentors:Dr. Ignacio Sirés Sadornil, Universitat de Barcelona, [email protected].

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A double microfluidic device combined with a HPLC procedure for the determination of emergent pollutants in environmental water.Elia Santigosa Murillo.

Centro Nacional de Microelectrónica de Barcelona (IMB-CSIC), Campus UAB, Carrer dels Til·lers, 08193 Cerdanyola del Vallès, Barcelona. [email protected]

This experimental work describes a double microfluidic-chip based liquid-phase microextraction and electromembrane extraction for the determination of emerging pollutants in water samples. The extract collected after each extraction is directly analyzed by HPLC.

The model analytes were four parabens [1] and five fluoroquinolones: Ethyl 4-hydroxybenzoate (EtP), Propyl 4-hydroxyben-zoate (PrP), butyl 4-hydroxybenzoate (BuP), isobutyl 4-hydroxybenzoate (iBuP); marbofloxacine (MRB), norfloxacine (NPF), danofloxacine (DNF), ciprofloxacine (CPF), flumequine (FLM).The fluoroquinolones were extacted during the first stage by EME whereas the parabens were extrated by LPME in a second stage.

The device is composed by four polymethylmetacrylate plates: two donor phases (both, parabens and fluorquinolones) and one acceptor phase. The acceptor phase was the same for both, the extraction of fluoroquinolones and parabens by EME and LPME, respectively. The donor phase and the acceptor phase were separated by a flat membrane (supported liquid membrane) located between both channels.

The pH of donor phase was 3.5 for parabens and 11 for fluoroquinolones while the acceptor phase was fixed at pH 11.5. The donor and the acceptor flow rate was 1 µL / min.

The extraction time and the sample volume for both extractions were 7 min and 100 µl, respectively. The microfluidic device allows good extraction efficiency and excellent clean-up under double flow conditions. This device also significantly reduces both costs and withdrawal time compared to existing methods for the extraction of parabens and fluoroquinolones.

References:1. Ramos et al. A simple and fast Double-Flow microfluidic device based liquid-phase microex-traction (DF-µLPME) for the determination of parabens in water samples. Talanta. 165, 496-501 (20017).

Advisers/Mentors:Dra. María Ramos Payán, Centro Nacional de Microelectrónica de Barcelona (IMB-CSIC), [email protected], [email protected]

ISE Session “Regional Student Meeting”

PhD STUDENTS

Wednesday 5th July 14:30 - 17:00

112

Replicating biological functions from multistep electrochemical molecular machines.Samuel Beaumont.

Laboratory of Electrochemistry Intelligent Materials and Devices. Technical University of Cartagena. ETSII. Campus Alfonso XIII. 30203. Cartagena. [email protected].

Human and animal muscles sense while working mechanical, thermal or chemical working conditions: they are haptic muscles. Currently the origin and nature of the sensing signal has not been clarified. While most of the researchers try to clarify this dual activity have been focused on the localization of the different physical sensors working in a muscle [1], some researchers suspect that the actuating reaction is the origin of some sensing signals sent back to the brain [2].

Electrochemical reactions of conducting polymers, and other electroactive materials, sense the working conditions, mimic-king many biochemical reactions involving macromolecules as reactants and originating biological functions. Our group has been working from the end of the past century on the sensing properties of the electrochemical reactions of conducting polymers, carbon nanotubes or graphenes [3]. While the sensing properties have been demonstrated empirically using different dual sensing/actuating devices based on conducting polymers (smart membranes, smart windows, artificial muscles..) [4] the origin and nature of the sensing signal has not been clarified yet.

It is our aim to do a deep study of the electrochemical reactions involving this multistep macromolecular machines, in order to demonstrate that the sensing signal is an inherent property of the reversible electrochemical reactions involving conduc-ting polymers during actuation. Formulating a new sensing principle by similitude with the Le Chatelier and Nerst sensing principles for chemical or electrochemical equilibrium: any change or perturbation of the reaction energetic conditions is sensed by the energy consumed during the reaction.

In order to achieve our aims, a deep study of the response during actuation of polypyrrole film coating a platinum electrode under different chemical, electrical and thermal perturbations will be performed. The polymeric material will be submitted to potential sweeps, potential square waves and current square waves in order to determinate the evolution of the potential reached, current peak and consumed charge while actuating in diverse working environment, getting the energy consumed by the electrochemical reaction as a sensing magnitude. Finally a deeper study is programmed to do using different materials, as well as different electrolyte and solvent. The new theoretical description would clarify the electrochemical origin of the dual sensor and actuator nature of this biomimetic materials, and inspires the development of new dual sensing/actuating devices.

References:1. S. Rossignol, R.J. Dubuc, J.P. Gossard, Dynamic sensorimotor interactions in locomotion, Physiol. Rev. 86 (2006) 89–154. doi:10.1152/00028.2005.2. H. Iwamoto, The earliest molecular response to stretch of insect flight muscle as revealed by fast X-ray diffraction recording, Sci Rep. 7 (2017) 42272. doi:10.1038/srep42272.3. T.F. Otero, J.G. Martinez, Physical and chemical awareness from sensing polymeric artificial muscles. Experiments and modeling, Progress in Polymer Science. 44 (2015) 62–78. doi:10.1016/j.progpolymsci.2014.09.002.4. T.F. Otero, From Electrochemically-Driven Conformational Polymeric States to Macroscopic and Sensing Artificial Muscles., in: J.-P. Sauvage, P. Gaspard (Eds.), From Non-Covalent Assemblies to Molecular Machines, Wiley-VCH, Weinheim, 2011: pp. 443–452.

Advisers/MentorsToribio F.Otero, Laboratory of Electrochemistry Intelligent Materials and Devices. Technical University of Cartagena. Email: [email protected].

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Determination of the speciation and bioavailability of Indium with electroanalytical techniques.Marjan Heidarkhan Tehrani.

Department of Chemistry, University of Lleida, Spain.

Indium is one of the metallic elements that causes significant environmental concern due to its toxicity, as well as acute and chronic poisonings when builds up in the body [1]. Therefore, it is very critical to be able to precisely determine its presence and its various chemical forms in various medias. Despite intensive work, Ion selective electrodes (ISE) for Indium are not commercially available. The main goal of this thesis is to investigate the capacity of the electroanalytical technique AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) in determining free Indium concentration in synthetic aqueous solutions. The hypothesis is that AGNES is a suitable technique for determining In+3, since Indium is an amalgamating element and has a negative standard redox potential [2]. To evaluate the speciation of Indium using AGNES, ligands such as Nitrilotriacetic acid (NTA) and Oxalate are used in this study. The lability degree of Indium is obtained through a novel technique named accumulation under diffusion limited conditions (ADLC). The free concentrations of Indium in precipita-ted solutions are measured at pH values in the range 5 to 6, reaching the picomolar range. A comparison between the measurements of AGNES and the predictions of VMINTEQ 3.1 is carried out for accuracy validation. When dealing with the system ln-NTA, models reported by Harris et al. [3] and Biver et al. [4] are in good agreement with AGNES measurements if the proportion of Ligand:Metal is less than 1:1. In the cases that this proportionality reaches 1:1 or when the total ligand concentration is higher than that of Indium, Harris predictions are significantly lower. The high lability and mobility of the In-Oxalate complex at pH 3 allow measurements below nanomolar in just 25 seconds, instead of the needed deposition time of around 3000000 s expected for a totally inert system. Finally, the kinetics and equilibrium dissolution of Indium nanoparticles (In2O3) is studied by measuring its free form in synthetic seawater solutions at pH 8 and for dispersions that contain KNO3 0.1M at pH 2 to 5. If we change the pH from 3 to 4, the free concentration at higher pH shifts to its equilibrium value with In hydroxides. However, no anodic stripping voltammetry peak for Indium is seen when nanoparti-cles are dispersed in synthetic seawater solutions at pH 8.

References:1.- White, S. J., & Hemond, H. F. (2012). Environmental Science and Technology, 42: 155-186.2.- Galceran, J., Huidobro, C., Companys, E., & Alberti, G. (2007). Talanta, 71: 1795-1803.3.- Harris WR, Chen Y, Wein K. (1994). Inorg Chem; 33: 4991-4998.4.- Biver T, Friani R, Gattai C, Secco F, Tine MR. (2008). J Phys Chem B, 112: 12168-12173.

Advisers/MentorsJosep Galceran and Encarna Companys, Department of Chemistry, University of Lleida, Spain, [email protected], [email protected]

Electro-Valorization of CO2 by Synthetizing Value-added Product Using Environmentally Friendly Strategies.Silvia Mena Fernández.

Departament de Química, Universitat Autònoma de Barcelona, Campus UAB, 08193-Bellaterra, Barcelona.E-mail: [email protected]

The CO2 emission is one of the problems with bigger attention in the entire world, since it is related in climate change. Therefo-re, it has been made big inversions in the development of different strategies to valorize CO2. [1] One of the most promising approaches for activating, capturing and valorizing CO2 is the use of electrochemical techniques. [2]

However, the direct electrochemically reduction and activation of CO2 involves high reduction potentials (EºCO2/CO2•- = -2,2 V vs SCE in aprotic media). [3] In this sense, the mediators should help to catalytic electroreduction of CO2.

In the current communication, it will be revised all the state of the art related to activation, valorization and storage of CO2. Furthermore, it will be analyzed the influence of the cathode’s nature, the solvent and mediators in order to promote the electrochemical activation of CO2. The last goal of the current study will be to valorize CO2 by synthesizing value-added chemi-cal using by Green Chemistry principles [4], in pharmaceutical industry as polymer industry.

References:(1) Yadav, G.; Sen, R. 2017, 17 (January), 188–206.(2) Albo, J.; Alvarez-Guerra, M.; Castaño, P.; Irabien, A. Green Chem. 2015, 17 (4), 2304–2324.(3) Reche, I.; Gallardo, I.; Guirado, G. RSC Adv. 2014, 4 (110), 65176–65183.(4) Alvarez-Guerra, M.; Albo, J.; Alvarez-Guerra, E.; Irabien, A. Energy Environ. Sci. 2015, 8 (9), 2574–2599.

Advisers/Mentors:Gonzalo Guirado/ Iluminada Gallardo; Departament de Química, Universitat Autònoma de Barcelona, Campus UAB, 08193-Bellaterra, Barcelona; [email protected] / [email protected]

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Development of Ionic Liquid-based Electrolytes for New Electrochemical Energy Storage Devices.Paula Navalpotro.

Electrochemical Processes Unit, IMDEA Energy Institute, Avda. Ramón de la Sagra 3, 28935 Móstoles, Spain. Email: [email protected]

In the dawn of a new renewable energy system based on natural and intermittent sources such as solar or wind, electroche-mical energy storage devices are being investigated to counteract the output fluctuations and maintain the reliability of grid operation [1]. In order to improve the performance of the devices and to achieve the new requirements for these applica-tions, the scientific community is focused on the study of new materials for their two basic components: electrodes and electrolyte [2].

Regarding this issue, the aim of this thesis is the formulation of new ionic-liquid based electrolytes and their application in electrochemical energy storage devices such as; i) high performing supercapacitors and ii) innovative concepts of redox flow batteries. In particular, this work will be orientated to study the use of redox electrolytes based of redox-active organic molecules for hybrid supercapacitors as well as its behavior in a new concept of membrane-free flow battery [3]. Therefore, during this period a deep study of the state of the art of organic redox electrolytes and its application in hybrid supercapaci-tors and redox flow batteries will be carried through. Subsequently, once the new electrolytes have been formulated, its electrochemical behavior will be investigated by electrochemical techniques such as, cyclic voltammetry, galvanostatic charge-discharge and impedance spectroscopy in 3-electrode electrochemical cell (half-cell). Afterwards, this kind of redox electrolytes will be used in hybrid supercapacitors with different types of carbon electrodes and their energy storage mecha-nism will be elucidated in full cells. Moreover, application of these redox electrolytes in a new concept of Membrane-free battery will be investigated. This revolutionary concept relies on the immiscibility of redox electrolytes, having a biphasic system which behaves as a reversible battery without any membrane or separator. For the development of this totally new technology, thermodynamic and engineering aspects will be discussed. Finally, a lab scale prototype will be designed and assembled to demonstrate the feasibility of this ground-breaking battery. As a result, this thesis will contribute to expand the knowledge about electrochemical energy storage devices and open up new opportunities for these technologies.

References:1. a) J. Rugolo and M. J. Aziz, Energy Environ. Sci., 5, 7151 (2012). b) Z. Yang et al., Chem. Rev., 111, 3577–3613 (2011).2. a) F. Béguin, V. Presser, A. Balducci, and E. Frackowiak, Adv. Mater., 26, 2219–2251 (2014). b) W. Zuo et al., Adv. Sci., 1600539 (2017). c) P. Alotto, M. Guarnieri, and F. Moro, Renew. Sustain. Energy Rev., 29, 325–335 (2014).3. a) P. Navalpotro, J. Palma, M. Anderson, and R. Marcilla, J. Power Sources, 306, 711–717 (2016). b) P. Navalpotro, J. Palma, M. Anderson, R. Marcilla. Manuscript under revision. c) P. Navalpotro, J. Palma, M. Anderson, and R. Marcilla, Patent application P201630327, priority date 21/03/2016.

Advisers/MentorsDr. Rebeca Marcilla, Electrochemical Processes Unit, IMDEA Energy Institute, Avda. Ramón de la Sagra 3, 28935 Móstoles, Spain. Email: [email protected]. Jesus Palma, Electrochemical Processes Unit, IMDEA Energy Institute, Avda. Ramón de la Sagra 3, 28935 Móstoles, Spain. Email: [email protected]

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Development of novel inorganic electrolytes to engineer rechargeable sodium batteries.Débora Ruiz.

Departament de Química Física i Institut Universitari d’Electroquímica, Universitat d’Alacant, Apartat 99, E-03080 Alicante, [email protected]

Over the last several years, research on rechargeable sodium ion or sodium metal batteries has received a great deal of attention as an alternative to lithium secondary batteries in energy storage for the electric grid. This is related to the considera-ble price reduction and the larger abundance of Na in the Earth´s crust in comparison to lithium. However, due to the size of the Na+ ion (0.102 nm) compared to that of lithium ion (0.076 nm) and the poor electrochemical reversibility of sodium, it is difficult to find a suitable host material for reversible Na-ion or Na-metal storage. In addition, it seems necessary to develop new electrolytes capable to provide a non-dendritic and reversible plating/stripping of sodium as well as new candidates as active material capable to resist significant changes in volume in the cathode side.

The goal of this PhD thesis is to contribute to the development of sodium ion and sodium metal batteries. Our research focuses on the design on new inorganic and non-conventional electrolytes based on liquid ammonia [1]. These electrolytes have a concentration over 7 M in the sodium salt. This characteristic allows for a highly reversible electrochemical behavior of metallic sodium with an extremely fast kinetic of the process of plating/stripping as well as high stability of the sodium metal in the electrolyte. In addition, based on the outstanding performance of the sodium electrode, the sodium deposition on other metallic substrates with high reversibility is also possible. This advantage gives the possibility to assemble the device avoiding handling metallic sodium. Regarding the cathodic side, different materials have been studied. On the one hand, the possibility of using cathodes based on inorganic material such as amorphous titanium dioxide with different morphologies has been considered. These appear to be promising for rechargeable sodium batteries according to the bibliography, and it could be a suitable candidate for inorganic ammonia-based electrolytes. On the other hand, organic molecules could also be considered as active cathode materials. For instance, quinones and dyes could be promising electrodes for the inorganic electrolytes as they have a high theoretical capacitance. In addition, they could withstand significant changes in volume entailed by the process of insertion and deinsertion of sodium. Finally, the combination of the different elements described above can lead to the design of new rechargeable sodium batteries, which will have as main characteristics high power densities and gravimetric capacities, having the potential to be a competitive alternative to lithium-based batteries.

References:[1] A.-M. Gonçalves, P. Tran-Van, G. Herlem, E. Kwa, B. Fahys, M. Herlem, Port. Electrochim Acta 24 (2006) 117-127

Advisers/Mentors:Roberto Gómez, Departament de Química Física i Institut Universitari d’Electroquímica, Universitat d’Alacant, Apartat 99, E-03080 Alicante, Spain. [email protected]

Graphene-based materials for hybrid electrochemical energy storage devices.Jaime Sánchez Sánchez.

Electrochemical Processes Unit, IMDEA Energy Institute, Avda. Ramon de la Sagra 3, Parque Tecnológico de Móstoles, 28935 Móstoles, Spain. [email protected]

Increasing environmental concerns and depletion of fossil fuels have greatly stimulated development of reliable energy storage devices able to fulfill ever-increasing energy and power needs. Supercapacitors generally store charge as electric double layer capacitance (EDLC) providing high power densities while batteries store energy through reversible Faradaic redox reactions achieving high energies. Recently, combining these two energy storage mechanisms within a hybrid material has attracted great attention, offering a promising strategy to construct devices with merits of both batteries and supercapacitors.[1,2] Among different types of carbon, graphene is of exceptional interest in energy storage applications due to its excellent conductivity and high specific surface area. However, its practical capacitance/capacity is not yet satisfac-tory (typically 130-260 F.g-1/36-72 mA.h.g-1) mainly due to restacking of the layers. Hence, graphene can be best exploited in hybridization with battery-type materials such as metal oxides to achieve materials with improved properties, and this is the main motivation and goal of the present research.[3]

Accordingly, various compositions of single and mixed metal oxides (e.g. Fe3O4, NiCoMnO4, etc.) with graphene are synthe-sized through chemical or electrochemical routes. The prepared samples are carefully characterized via different techniques including X-ray diffraction, Raman, X-ray photoelectron spectroscopy, electron microscopies and gas adsorption/desorp-tion. The electrochemical properties of the samples are investigated through different techniques such as cyclic voltamme-try, chronopotentiometry and electrochemical impedance spectroscopy. Moreover, samples are employed as electrode materials (negative or positive) in full devices and their energy storage properties in terms of capacity, rate capability and cycling stability are examined and compared with the previously reported materials.

References:[1] W. Zuo, R. Li, C. Zhou, Y. Li, J. Xia, J. Liu, Battery-Supercapacitor Hybrid Devices: Recent Progress and Future Prospects, Adv. Sci. (2017) 1600539. [2] J.S. Sanchez, A. Pendashteh, J. Palma, M. Anderson, R. Marcilla, Anchored Fe3O4 Nanoparticles on rGO Nanosheets as High-Power Negative Electrodes for Aqueous Batteries, ChemElectroChem. (2017) 1–12. [3] G.H. Jeong, S. Baek, S. Lee, S. Kim, Metal Oxide / Graphene Composites for Supercapacitive Electrode Materials, Chem. Asian J. 11 (2016) 949–964.

Advisers/MentorsRebeca Marcilla, Electrochemical Processes Unit, IMDEA Energy Institute, Avda. Ramon de la Sagra 3, Parque Tecnológico de Móstoles, 28935 Móstoles, Spain; [email protected] Pendashteh, Electrochemical Processes Unit, IMDEA Energy Institute, Avda. Ramon de la Sagra 3, Parque Tecnológico de Móstoles, 28935 Móstoles, Spain; [email protected]

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Development of self-sensing systems comprising polymeric artificial muscles.Johanna Schumacher.

Technical University of Cartagena, ETSII, Campus Alfonso XIII, 30203, Cartagena, Spain. Arquimea Ingeniería., 28919, Leganés, Spain. Email: [email protected]

Skeleton muscles and tendons are able to sense their relative position and the required force while they contract and expand via specific organs. Actuation and sensing occur at the same time. Similar abilities were discovered for electroactive materials based on conducting polymers which sense temperature, electrolyte concentration, and trailed mass while moving [1–3]. Dual sensing-actuating artificial muscles based on these materials driven by electrochemical reactions announce the development of self-sensing devices. Several sensors and a faradaic motor work simultaneously in one uniform device driven by the reaction of the constitutive material, like skeleton muscles do [4]. The integration of dual sensing artificial muscles into devices could reduce the complexity, the size and the control effort of nowadays technology.

The aim of the project is the investigation of novel materials for dual sensing-actuating artificial muscles and the development of a proof of concept for industrial applications. Electroactive materials are synthesized and characterized, in particular basic conducting polymers such as polypyrrole and its composites with reasonable life time, reproducibility and stability. With these electroactive materials, dual sensing-actuating artificial muscles are fabricated and tested under different experimental conditions. Furthermore, novel configurations of these motors are designed and tested. Based on the experimental results theoretical descriptions are derived, characteristic material values are determined and the existing proprioceptive model [1–3] is adopted in terms of real world environment. In the second phase of the project a functional demonstrator is developed and fabricated as a proof of concept. Based on the updated proprioceptive model and the application requirements a control system for self-sensing systems is developed and the demonstrator is designed. The demonstrator will show the potential of dual sensing-actuating polymeric artificial muscles for future technology.

References:1] Martínez, J. G.., Otero, T. F., “Biomimetic dual sensing-actuators: theoretical description. Sensing electrolyte concentrationand driving current,” J. Phys. Chem. B 116(30), 9223–9230 (2012).[2] Otero, T. F., Sanchez, J. J.., Martinez, J. G., “Biomimetic dual sensing-actuators based on conducting polymers. Galvanostatic theoretical model for actuators sensing temperature,” J. Phys. Chem. B 116(17), 5279–5290 (2012).[3] Martínez, J. G.., Otero, T. F., “Mechanical awareness from sensing artificial muscles: Experiments and modeling,” Sens. Actuators B Chem. 195, 365–372 (2014).[4] Otero, T. F., “Biomimetic conducting polymers: synthesis, materials, properties, functions, and devices,” Polym. Rev. 53(3), 311–351 (2013).

Acknowledgements: This project is funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodoska-Curie grant agreement No 641822.

Advisers/Mentors:Toribio F. Otero, Laboratory of Electrochemistry and Intelligent Materials, Technical University of Cartagena, ETSII, Campus Alfonso XIII, 30203, Cartagena, Spain. Email: [email protected] Collado, Arquimea Ingeniería, 28919, Leganés, Spain. Email: [email protected]

Analysis of the influence of different non-idealities and complex reaction schemes on the charge transfer processes of surface confined redox species.José Alfonso Sequí.

Department of Physical Chemistry. Chemistry Faculty of the University of Murcia, 30100 Espinardo, [email protected]

Modification of conducting surfaces by means of the immobilization of electroactive species allows designing new functio-nal interfaces for their application to a great number of practical applications. The electrochemical characterization of these systems gives rise very frequently to non-ideal responses in the sense that they show different features which are not predic-ted by simple, ideal models. Among the causes of non-idealities are the presence of intermolecular interactions, the presen-ce of a molecular heterogeneity at the surface which causes the appearance of thermodynamic or kinetic dispersion, and also the possibility of complex reaction schemes [1, 2].

Figure 1. Scheme of the main purpose of the present research

Aiming for the comprehensive analysis of surface electrochemical processes, the goal of this project is to obtain rigorous solutions for the current-potential and charge potential responses in order to analyze and evaluate the influence of the different non-idealities of the reaction scheme. Although currently Cyclic Voltammetry (CV) is the most used electrochemi-cal technique for the analysis of these type of processes, we will focus our studies in multipotential pulse techniques such as Staircase Voltammetry and Square Wave Voltammetry, together with their voltcoulometric modalities, since they allow performing a more direct kinetic analysis of the response than CV. Experimental verification of the proposed method will be done with different electroactive species.

References:1. A. Molina, J. González, Pulse Voltammetry in Physical Electrochemistry and Electroanalysis, Springer, 20162. J. J. Calvente, R. Andreu, Current Opinion in Electrochemistry, 1 (2017) 22-26

Acknowledgements:The author greatly appreciates the financial support (Fundación SENECA (Proyect 19887/GERM/15) and Ministerio de Economía y Competitividad (CTQ2015-65243-P)

Advisers/Mentors:Joaquín González Sánchez, Universidad de Murcia, 30100, Murcia, Spain; [email protected].

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EC-FTIR studies for Ethanol electrooxidation in alkaline media with different catalysts.Jorge Torrero Cámara.

Instituto de Catálisis y Petroleoquímica, CSIC. C/ Marie Curie 2, 28049, Madrid, Spain.

Direct Alcohol Fuel cells (DAFCs) are Fuel Cells in which alcohol is used directly as fuel. Most studies DAFCs have been perfor-med using methanol as fuel. However, the use of ethanol offers certain advantages as to the fact that ethanol obtained from renewable sources is less toxic and it has higher energy density than methanol [1]. Pt based catalysts are the most active ones for the electrooxidation of alcohols. However, the formation of intermediate species such as COad results in the poisoning of Pt. In order to overcome this issue, PtM where M is an oxophilic metal such as Ru or Sn promotes the oxidation of such intermediate species. This strategy fails to promote the complete electro-oxidation of ethanol, because C-C bonds are difficult to activate at low temperatures. In order to improve the design of new catalysts it is necessary to identify the nature of adsorbed species during the ethanol oxidation reaction (EOR). One of the tactics for this end is the use of in operando spectros-copies, typically IRRAS (infrared reflection absorption spectroscopy). This technique has been widely used for the study of the electrooxidation of alcohols in acid media [2]. Despite the rising interest in alkaline fuel cells due to the faster kinetics for the electrooxidation of alcohols [3], in operando studies during the EOR in alkaline electrolyte are scarce. We have studied the EOR using in operando IRRAS with Pt/C, PtRu/C and Pt3Sn/C catalysts in both H2O (Fig. 1) and D2O (not shown) alkaline electrolytes in order to identify properly the intermediate species overcoming the overlapping of vibrational bands of H2O. Spectra (repor-ted as the R/R0 ratio) were acquired during positive sweep at 1mVs.

Figure 1. Selected IRRAS with a) Pt/C, b)PtRu/C and c) Pt3Sn/C during EOR (0.5M CH3CH2OH) in 0.1M KOH/H2O at 1mVs-1.

The spectra shown in Figure 1 demonstrate that the EOR proceeds by different pathways on each catalysts. Thus, at low potentials only Pt/C shows the formation of COad (band at 2020 cm-1) indicating the scission of the C-C bond. Acetates (bands at 1410 and 1550 cm-1) are the most abundant species at high potentials.

References:1. Antolini, E, J. of Power Sources, 2007. 170(1): p. 1-12.2. Torrero, J., Pérez-Alonso, F. J., Peña, M. A., Domínguez, C., Al-Youbi, A. O., Al-Thabaiti, S. A., Rojas, S.. ChemElectroChem, 2016. 3(7): p. 1072-1083.3. L. Ma, D. Chu and R. Chen, Int. J. Hydrogen Energy 2012, 37, 11185-11194.

Advisers/Mentors:Sergio Rojas, Instituto de Catálisis y Petroleoquímica, CSIC, [email protected]. Miguel A. Peña, Instituto de Catálisis y Petroleoquímica, CSIC, [email protected].

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Thorough assessment of reaction pathways involved in the electochemical removal of persistent organic micropollutants from water.Zhihong Ye.

Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona. [email protected]

Water pollution by persistent emerging organic micropollutants is widely regarded as a vital environmental concern on a global scale. In this PhD, single and combined electrochemical technologies (electrocoagulation (EC) and electrochemical advanced oxidation processes (EAOPs)) are proposed as effective technologies to treat aqueous solutions containing refractory xenobiotics like benzophenone-3 (BP-3) and butylated hydroxyanisole (BHA) at both, lab- and pilot-scale (up to 3 L). Trials will be made in synthetic, simulated and real water (i.e., wastewater treatment plant) matrices.

To optimize the EC treatment, the effect of conventional parameters such as anode nature (Fe, Al and stainless steel), connection mode and current density will be investigated. In addition, aiming to enhance the economic feasibility, new aspects will be surveyed: the use of alternating current (AC) and polarity reversal, the performance of three-dimensional EC reactors and their operation in continuous mode. In EAOPs, aiming to avoid the limitations of acidification and constant pH adjustment that are typical of electro-Fenton (EF), photoelectro-Fenton (PEF) and solar photoelectro-Fenton (SPEF) processes performed at optimum pH 3.0, iron-chelating agents like Fe(III)-EDDS will be employed, since they are able to continuously dose catalytic amounts of Fe2+ at circumneutral pH [1].

Carbon-based electrodes are commonly used as cathodes to generate H2O2 from the two-electron reduction of O2. To further enhance the H2O2 supply, carbon-felt-based metal-organic frameworks (MOFs), with fascinating large surface area, will be employed to prepare novel efficient cathodes. Furthermore, new dimensionally stable anodes will be evaluated to minimize the concentration of chlorinated oxyanions typically accumulated in chloride-containing media. Since transforma-tion products formed upon treatment of micropollutants are potentially more persistent and/or toxic than the parent compounds, a thorough assessment of reaction pathways will be carried out in all electrolytic trials, using conventional offline chromatographic techniques as well as advanced offline and online GC-MS and LC-MS to have a more accurate idea of the complex routes.

References:1. W.H. Huang, M. Brigante, F. Wu, C. Mousty, K. Hanna, G. Mailhot. Environ. Sci. Technol. 47 (2013) 1952-1959.

Acknowledgements:Financial support from project CTQ2016-78616-R (AEI/FEDER, EU), as well as from the PhD grant awarded to Z.H. Ye (CSC, China) is acknowledged.

Advisers/MentorsDr. Ignacio Sirés Sadornil, Universitat de Barcelona, [email protected].

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Begoña Acebedo. Aleaciones basadas en Sn y Sb como electrodos negativos en baterías de ion sodio.

Débora Ruiz.Uncommon inorganic electrolyte for sodium-ion batteries: Study of amorphous TiO2 nanotubes. Dmitry Galyamin.New approach for bacteria endotoxins detection based on a modified three-dimensional impedimetric transducer.

Elisa Vallés. Magnetostrictive Fe1-xGax films prepared by electrodeposition.

Elvira Gómez.Janus electrodes. Functionalization tailored by gold nanoparticles in different media.

Enrique Herrero.Electro-oxidación glicerol en superficies de Au: Efecto de la adición de Pd.

Felipe Hernández-Luis. Coeficientes de actividad del NaCl en mezclas acuosas con co-disolvente ε-increasing: N-metil-acetamida (NMA) + agua a 298.15 K.

Francesc Estrany.Aumento de la electroactividad de films de Poli(N-Metilpirrol) por incorporación de nanopartículas de trióxido de molibdeno.

Francisco Cases.Tejidos de carbón activo modificados superficialmente con óxido de grafeno reducido y polímeros conductores. Estudio de su capacidad específica.

Francisco Prieto.Preparación y Estudio de Estabilidad Termodinámica y Electroquímica de Películas Superficiales de Fosfolípidos para la Administración y Liberación de Doxorubicina.

Inmaculada Márquez.Efecto de mutaciones alejadas del centro redox sobre las transiciones ácida y alcalina de plastocianinas de cianobacterias.

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Jerónimo Agrisuelas.RGB Video Electrochemistry: Application to the characterization of passivated Ni/POT electrodes.

Jesús Iniesta.The electrochemistry of brominated guanine and cytosine at carbon based electrodes towards epigenetic sensing.

José García-Antón.Novel ZnO/ZnS heterostructures synthetized by electrochemical anodization under controlled dynamic conditions in glycerol based electrolytes.

Josep Galceran. Towards the determination of [Sb(OH)3] with AGNES.

Juan Daniel Mozo. Adsorción de compuestos quinolínicos sobre nanotubos de carbono de pared múltiple (MWCNT). Estudios espectroscópicos y electroquímicos.

Juan Miguel López del Amo.Characterization of Na-based cathode materials by solid state NMR.

Laura Acebo. Strategies to improve the electrochemical performance of a Na manganese-based layered oxide.

Mª. Aránzazu Goicolea.Solid-phase synthesis of imprinted nanoparticles as high affinity recognition elements for chiral sensing.

María Pilar Rivas Romero.Comparison of electrochemical and spectropho-tometrical methods for the determination of antioxidant capacities of healthy food components.

Maialen Sánchez. Use of complementary techniques in characterization of carbon supports for PEMFC.

Mónica Revenga. Reducción y modificación química de grafeno en un solo paso para el desarrollo de plataformas electrocatalíticas.

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Pilar Ocón.A composite polymer electrolyte based on Poly(vinylidene Fluoride) and Poly(vinyl Alcohol) for Lithium-Ion batteries.

Valentín Pérez-Herranz. Electrochemical Degradation of Atenolol with Boron-Doped Diamond Electrodes.

Zihong Ye.Coupling of electrocoagulation with electrochemical advanced oxidation processes for the removal of benzophenone-3.

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Aleaciones basadas en Sn y Sb como electrodos negativos en baterías de ion sodio.Begoña Acebedo.

B. Acebedo1, J.L. Gómez-Cámer1, N.E. Drewett1, M. Galceran1, T. Rojo1,2

1 CIC energiGUNE. c\ Albert Einstein 48. Parque Tecnológico de Álava. 01510 Miñano, Álava.2 Dpto. de Química Inorgánica, Universidad del País Vasco UPV/EHU, P. O. Box. 644, 48080 Bilbao, Spain.

Las aleaciones de Sn y Sb son unas de las alternativas más prometedoras para reemplazar al sodio metálico como electrodo negativo en baterías de ion sodio,[1,2] ya que, al reaccionar a potenciales ligeramente superiores, disminuyen el riesgo de deposición de sodio metálico mejorando notablemente su seguridad. Su capacidad para almacenar gran cantidad de iones Na+, unida a su alta densidad, proporciona un aumento significativo de la densidad energética en comparación con otros materiales como, por ejemplo, los basados en carbón. Puesto que el principal inconveniente que presentan estos materiales es el cambio de volumen durante los procesos de carga/descarga,[3] buena parte de la investigación relacionada con ellos se ha dirigido a la supresión de estos efectos negativos. Algunas de las estrategias empleadas han sido el uso, tanto de nanopartícu-las y nanoestructuras capaces de acomodar los cambios de volumen, como el de matrices conductoras de carbón o recubri-mientos, y también el diseño de nuevas aleaciones o compuestos intermetálicos del elemento activo con otros elementos, tanto activos o como inactivos frente a sodio.[4]

En esta comunicación se presenta la síntesis, la caracterización estructural y el estudio del comportamiento electroquímico de distintos materiales basados en Sn y en Sb, sintetizados por métodos clásicos en estado sólido y también mediante rutas de síntesis en disolución. La capacidad específica observada para los distintos materiales AxSny y AxSby (donde A = Fe, Ni, Ti, P), ciclados a C/10, se mantiene estable durante los primeros 100 ciclos de carga/descarga y se encuentra en el rango de 300 a 600 mAhg-1. Los buenos resultados obtenidos pueden deberse a una dispersión homogénea del componente activo en la matriz de metal inactivo y a su efecto de amortiguación de los cambios de volumen. Las diferencias entre los distintos materia-les se discuten en términos de composición, tamaño de partícula y rendimiento electroquímico.

Referencias:1. L. D. Ellis, T. D. Hatchard, M. N. Obrovac, J. Electrochem. Soc. 2012, 159, A1801.2. A. Darwiche, C. Marino, M. T. Sougrati, B. Fraisse, L. Stievano, L. Monconduit, J. Am. Chem. Soc. 2012, 134, 20805.3. V. L. Chevrier, G. Ceder, J. Electrochem. Soc. 2011, 158, A1011.4. H. Kang, Y. Liu, K. Cao, Y. Zhao, L. Jiao, Y. Wang, H. Yuan, J. Mater. Chem. A 2015, 3, 17899.

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Uncommon inorganic electrolyte for sodium-ion batteries: Study of amorphous TiO2 nanotubes.Débora Ruiz.

Débora Ruiz 1, Roberto Gómez 1

1 Departament de Química Física i Institut Universitari d’Electroquímica, Universitat d’Alacant, Apartat 99, E-03080 Alicante, [email protected]

Rechargeable sodium metal batteries have attracted attention as promising power sources over the last several years because they are a lower cost option for large scale energy storage (electric grid). However, the Na-metal anode is characterized by poor reversibility during long term cycling plating and stripping at room temperature. This is mainly due to the formation of nonuni-form solid electrolyte interfaces as well as to the dendritic growth of sodium metal. Here, we report on a highly-concentrated sodium electrolyte based on liquid ammonia in which a large amount of sodium salt has been dissolved. This electrolyte can be formulated as NaI·3.3NH3 [1]. It has excellent properties such as high ionic conductivity and non-flammability, which can offset excessive volatility. In addition, this electrolyte can provide a highly reversible and nondendritic plating-stripping of sodium metal at room temperature. However, the development of sodium based batteries is also limited by the requirement of finding active materials capable to be compatible with the electrolyte. Here we present an electrochemical study of electro-des based on amorphous nanotubes of titanium dioxide prepared by a simple anodization process [2]. The main important advantage is that these electrodes are prepared without any additive (conductive carbon or binder). Figure 1 shows a SEM image of an amorphous TiO2 nanotube electrode obtained by anodization as well as its electrochemical behavior in the NaI·3.3NH3 electrolyte. The insertion/deinsertion process of sodium is evinced, being characterized by its high reversibility even when employing a scan rate of 50 mV/s. The development of this kind of inorganic electrolytes based on liquid ammonia along with suitable cathodic materials, may pave the way for engineering new devices based on sodium with high power density at room temperature.

Figure 1. a) FE-SEM image of the nanotube film. b) Voltammogram for a TiO2 nanotube electrode in NaI·3.3NH3 at different scan rate.

Referencias:[1] A.-M. Gonçalves, P. Tran-Van, G. Herlem, E. Kwa, B. Fahys, M. Herlem, Port. Electrochim Acta 24 (2006) 117-127[2] M. Jankulovska, I. Barceló, T. Lana-Villarreal, R. Gómez, J.Phys. Chem. C 117 (2013) 4024-4031.

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New approach for bacteria endotoxins detection based on a modified three-dimensional impedimetric transducer.Dmitry Galyamin.

Dmitry Galyamin1, Sergi Brosel-Oliu2, Natalia Abramova3, Francesc-Xavier Muñoz4, Andrey Bratov5

1 BioMEMS Group, Institut de Microelectrònica de Barcelona, Centre Nacional de Microelectrònica (IMB-CNM, CSIC), Barcelona, Spain.

Bacterial endotoxins, also known as lipopolysaccharide (LPS), are contaminants produced by gram-negative bacteria and habitually found in food which can induce immune response producing fever, endothelial damage or multi system organ failure [1]. An impedimetric transducer based on a 3D interdigitated electrode array (3D-IDEA) (Fig. 1) was used to study interactions with LPS in a sample solution. LPS immobilization on the sensor surface affects the surface charge and produ-ces changes in the superficial resistance which are registrated using impedance spectroscopy technique [2].

Concanavalin A (Con A), a lectin with specific binding ability to LPS, was used as a biorecognition element. Immobilization of Con A on the surface was carried out using layer-by-layer method with polyethylenimine (PEI) polycation as an initial layer. To prevent non-specific adsorption of LPS different ways of surface blocking were tested to guarantee the specific response of Con A to LPS. The best results on selective detection of LPS were achieved by modifying sensors with Con A – Glycogen (Gly) multilayers, resulting in a highly sensitive, selective and reproducible response in the presence of E.coli LPS, with fast response time of about 20 minutes. Detection limit of the sensor with PEI-(ConA-Gly)2-ConA was found to be as low as 1 µg LPS/mL. The sensor response follows the Langmuir adsorption curve and can be perfectly fitted by Hill’s equation (Fig. 2).

Fig. 1: Schematic representation of 3D-IDEA Fig. 2: Response of modified sensor with

PEI-(ConA-Gly)2-ConA

References:1. J. Rosenfeld et al., Endotoxin (Lipopolysaccharide) Neutralization by Innate Immunity Host-Defense Peptides. J. Biol. Chem. 2006, 281:1636-16432. A. Bratov et al., Response of a microcapillary impedimetric transducer to changes in surface conductance at liquid/solid interface. Journal of Colloid and Interface Science, 403, 151-156 (2013).

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Magnetostrictive Fe1-xGax films prepared by electrodeposition.Elisa Vallés.

A. Serrà1, C. Vargas2, G. Murillo2, J. Esteve2, E. Vallés1

1 Grup d’Electrodeposició de Capes Primes i Nanoestructures (Ge-CPN), Dpt. Ciència de Materials i Química Física, Institut de Nanociència i Nanotecnologia (IN2UB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona.2 Instituto de Microelectrónica de Barcelona, IMB-CNM(CSIC), Campus UAB, Cerdanyola del Vallès, Barcelona.

Magnetostrictive Fe1-xGax films are of great interests for sensors and actuators, due to their mechanic and magnetic properties. Shape or elongation of the material can be changed during the application of a magnetic field. Galfenol films (Fe1-xGax with x around 0.2) present much enhanced magnetostrictive properties respect to pure Fe, Ni or Co. The magnetoeleastic properties of the galfenol make them a promising material to be used in some medical applications, such as stimulation of vital functions of living cells. Some authors have been proposed the preparation of galfenol by means of electrodeposition technique, althou-gh the co-deposition is not easy because the standard reduction potential of gallium is very negative.

In this work we propose the preparation of galfenol on two flexible polymeric substrates (Melinex, 90 µm thick and Topas, 50 µm thick) in order to test the magnetostrictive properties of the deposits. Thin (100-200 nm thick) films were prepared over the polymeric sheets containing seed-layers (Cr(10nm)/Au(100nm)) enabling conductivity to the substrate. After that, cantile-vers of polymer/Cr/Au/galfenol composite were prepared to test the response of the materials to the action of magnetic field.

Electrodeposition technique (potentiostatic or pulsed), composition of the solution and deposition conditions have been adjusted to obtain uniform films of galfenol composition (Figure 1)

Figure 1. Electrodeposited Fe0.8Ga0.2 films prepared at -1.6 V (vs. Ag/AgCl/KCl(3M)) on Topas/Cr/Au sheets in a solution contai-ning FeCl2 + Ga2(SO4)3 + H3BO3 + sodium citrate + ascorbic acid.

References:1. Magnetic nanoparticle-based approaches to locally target therapy and enhance tissue regeneration in vivo, R. Sensenig, Y. Sapir, C. MacDonald, S. Cohen, B. Polyak, Nanomedicine 7 (2012) 1425–1442

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Electro-oxidación glicerol en superficies de Au: Efecto de la adición de Pd.Enrique Herrero.

Gisele Afonso Bento Mello1, Carlos Busó-Rogero2, Enrique Herrero2 y Juan M. Feliu2

1 Instituto de Química, UFMS, C.P. 549, 79070-900, Campo Grande-MS, Brasil.2 Instituto de Electroquímica, Universidad de Alicante Apdo. 99 E-03080 Alicante.

Los estudios de electrocatálisis en la oxidación de glicerol son interesantes debido a su potencial uso en el ánodo de pilas de combustible alcalinas. Esta reacción produce una gran variedad de productos alternativos, como gliceraldehído, glicera-to o mesoxolato, entre otros [1, 2]. Sin embargo, el objetivo principal es alcanzar la oxidación completa hasta CO2 (carbona-to en medio alcalino), minimizando la formación de otros productos. Como catalizador, el oro se muestra más activo que el platino debido a su bajo envenenamiento de la superficie metálica. Para tratar de mejorar su capacidad catalítica, se proponen superficies de oro modificadas con paladio siguiendo diferentes métodos [3]: i) adsorción irreversible, donde el depósito metálico se realiza a circuito abierto a través de reacciones redox en la superficie del catalizador; ii) depósito forzado, adsorbiendo el Pd con la ayuda de una atmósfera reductora (H2/Ar); y iii) salto de potencial, donde la adsorción del paladio se realiza a potencial controlado. En este contexto, se investiga la influencia del método de depósito sobre la oxidación de glicerol en medio alcalino, utilizando voltametría cíclica para conocer la reactividad de cada superficie. Se observa mayor actividad en el caso del depósito por adsorción irreversible. Además, se detectan los intermedios de reacción y los productos finales formados mediante técnicas FTIR in situ, destacando la formación de CO2 a partir de 1 V.

Figura 1: Oxidación de glicerol 1.67 x 10-1 M en las superficies Au-Pd: a) Voltametría cíclica a 0.05 V s-1 y b) espectros FTIR para el depósito realizado por adsorción irreversible, usando como referencia el espectro a 0.1 V.

References:1. D.Z. Jeffery, G.A. Camara, Electrochem. Commun. 12 (2010) 1129.2. M. Simoes, S. Baranton, C. Coutanceau, Appl. Catal. B-Environ. 93 (2010) 354.3. B. Alvarez, V. Climent, J.M. Feliu, A. Aldaz, Electrochem. Commun. 2 (2000) 427.

Agradecimientos: Ministerio de Economía y Competitividad (CTQ2016-76221-P) y Generalitat Valenciana (PROMETEOII/2014/0139). GABM agradece también el apoyo a su beca postdoctoral CNPq - PDE 233268/2014-6.

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Janus electrodes. Functionalization tailored by gold nanoparticles in different media. Elvira Gómez.

Elvira Gómez1, Elisa Vallés1, David Ibáñez2, Álvaro Colina2, Aránzazu Heras2.

1 Grup d’Electrodeposició de Capes Primes i Nanoestructures (GE-CPN). Dep. Ciència de Materials i Química Física and Institut de Nanociència i Nanotecnologia (IN2UB). Universitat de Barcelona 08028 Barcelona. Spain.2 Department of Chemistry, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.

Janus materials are a new generation of nanomaterials that open a wide field of possibilities in materials science since the biased functionalization of a nanomaterial allows tuning or enhancing some of their properties. The asymmetry of Janus membranes provides a unique factor in the development and design of new architectures with dual nature in the same structure.

Many materials are employed in the fabrication of Janus structures. In this work, an innovative factor is proposed to fabrica-te Janus structures based on carbon nanotubes, like is the use of free-standing single-walled carbon nanotubes (FS-SWCNT) (Figure 1a). The use of these thin carbon nanotube membranes as electrodes and their modification with different nanoma-terials on each side open the door to an infinite number of applications.

Although different methods can be followed to develop Janus structures, the electrochemical functionalization has been proven to be one of the least expensive and most useful procedures, allowing the preparation of a wide range of nanostructures. On the other side, double functionalization of the two faces of very thin membranes is highly complicated due to the capillary limitation, in which the solution gradually penetrates through the membrane pores, leading usually to the same modification on both sides of the membrane. To overcome this limitation, we propose the use of two immiscible solutions (aqueous and hydrophobic ionic liquid) for the simulta-neous functionalization of thin carbon nanotube membranes that leads to a uniform modification of the two faces of these membranes.

In recent years, gold nanoparticles (AuNPs) have increased their applicabili-ty due to their high electron densities, stability and capability to combine with biomolecules. The main objective of this work is the fabrication of Janus nanostructure by functionalization of only one face of a FS-SWCNT membrane by the electrodeposition of AuNPs from aqueous media (sulpha-te and chloride) and an ionic liquid solution. The ionic liquid selected has been 1-butyl-1-methylpyrrolidinium bis(trifluoro-methanesulfonyl)imide (BmpyrNTf2) that is an air and water stable liquid with a highly hydrophobic behaviour. In this way, a Janus nanomaterial is obtained with the characte-ristic properties of SWCNTs on one face, and those specific of AuNPs on the other one (Figure 1b). The study in three media provides a wide potential range for AuNPs deposition. The suitable medium will be selected for double Janus functionalization according to the counterpart metallic species.

Acknowledgements:Financial support from Min isterio de Economía y Competitividad (CTQ2014-61914-EXP, CTQ2014-55583-R, TEC2014-51940-C2-2R, CTQ2015-71955-REDT) and Junta de Castilla y León (BU033-U16) is gratefully acknowledged.

Figure 1. (a) FS-SWCNT film without physical support. (b) SEM image of AuNPs electrogenerated.

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Coeficientes de actividad del NaCl en mezclas acuosas con co-disolvente ε-increasing: N-metil-acetamida (NMA) + agua a 298.15 K.Felipe Hernández-Luis.

Felipe Hernández-Luis1, Raquel Rodríguez-Raposo1, Héctor R. Galleguillos2, Jaime W. Morales3

1 Departamento de Química, U. D. Química- Física, Universidad de La Laguna, Tenerife, España.2 Departamento de Ingeniería Química, Universidad de Antofagasta, Chile.3 Escuela de Ingeniería Química, Pontificia Universidad Católica de Valparaíso, Chile.

Las disoluciones electrolíticas en medios acuo-orgánicos son muy importantes en campos tales como la química, ingeniería química, biología, bioquímica, bio-electroquímica, industria farmacéutica, etc. Por este motivo, nuevos datos sobre propieda-des termodinámicas y de transporte de estas disoluciones son siempre un aporte importante a la bibliografía científica.

Este trabajo es una continuación de estudios previos de determinación de coeficientes de actividad de haluros sódicos, tanto en disolventes acuosos con co-disolventes ε-decreasing (metanol, etanol, PEG, ...) [1-3] como en co-disolventes ε-increasing (formamida, N-metilformamida, EC,...) [4-6]. Los coeficientes de actividad del NaCl en las mezclas N-metil-acetamida (NMA) + agua a 298.15 K, se determinaron experimentalmente utilizando la siguiente célula electroquímica bi-ISE:

Na-ISE | NaCl (m), NMA (Y), H2O(100-Y) | Cl-ISE

El porcentaje de NMA en la mezcla (Y) varió entre 0 y 80% (límite de solubilidad de esta amida en agua a 25ºC). La molalidad (m) varió entre 0.04 mol·kg-1 y hasta casi la saturación en cada mezcla estudiada. Aplicando la ecuación de Nernst-Nikolsky, se obtiene:

E =E0* - 2k log mγ

La determinación del potencial estándar aparente, E0*, se realizó utilizando los métodos de extrapolación de rutina junto con las ecuaciones de Debye-Hückel (DH), Scatchard (S), Pitzer (P) y el más reciente modelo three characteristic-parameter-correla-tion (TCPC). Los cuatro modelos concuerdan bastante bien. Esto nos permite hacer una buena estimación estadística de E0* y podemos calcular con precisión los γ del NaCl, , Kps, nhidr, etc. La variación de los coeficientes de actividad con la concentra-ción presenta el típico perfil con una fuerte disminución inicial (interacción ion-ion) y un posterior aumento (interacción ion-disolvente). Para una concentración dada los coeficientes de actividad aumentan con el contenido de NMA en la mezcla, es decir con el aumento en la constante dieléctrica del medio.

Referencias:1. F. Hernández-Luis, M. V. Vázquez, M. A. Esteso, J. Mol. Liquids 108 (2003) 283-301.2. F. Hernández-Luis, H. R. Galleguillos, T. A. Graber, M. E. Taboada, Ind. Eng. Chem. Res. 47 (2008) 2056-2062.3. F. Hernández-Luis. R. Rodríguez-Raposo, J. W. Morales, H. R. Galleguillos, Fluid Phase Equilibria, 295 (2010) 163-171.4. F. Hernández-Luis, H. R. Galleguillos, L. Fernández-Mérida, O. González-Díaz, Fluid Phase Equilibria, 275 (2009) 116-126.5. F. Hernández-Luis, R. Rodríguez-Raposo, H. R. Galleguillos, J. W. Morales, J. Chem. Eng. Data 55 (2010) 3349-3355.6. F. Hernández-Luis, R. Rodríguez-Raposo, H. R. Galleguillos, J. W. Morales, J. Chem. Eng. Data J. Chem. Eng. Data 55 (2010) 3786-3792.

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Aumento de la electroactividad de films de Poli(N-Metilpirrol) por incorporación de nanopartículas de trióxido de molibdeno. Francesc Estrany.

Francesc Estrany1,3, Margarita Sanchez-Jiménez1, y Carlos Alemán2,3

1 Departament d’Enginyeria Química, E. U. d’Enginyeria Tècnica Industrial de Barcelona, Universitat Politècnica de Catalunya (U.P.C.), Comte d’Urgell 187, 08036 Barcelona, Spain. Email: [email protected] Departament d’Enginyeria Química, E. T. S. d’Enginyers Industrials, U. P. C., Diagonal 647, 08028, Barcelona, Spain. Email: [email protected] Center for Research in Nano-Engineering, U. P. C., Campus Sud, Edifici C’, C/Pasqual i Vila s/n, Barcelona E-08028, Spain. Email: [email protected].

El poli-(N-metilpirrol) (PNMPy), tiene importantes aplicaciones como la detección selectiva de dopa-mina [1], dispositivos electrocrómicos [2], y en la fabricación de supercapacitores [3].

En el presente trabajo, se han electrogenerado films compuestos de poli(N-metilpirrol) por incorpora-ción de partículas de MoO3, trabajando a potencial constante de 1,40 V durante 180s, a partir de una solución 10 mM de NMPy y 0,1 M de LiClO4, con 10% (sobre peso de monómero) de partículas del óxido en suspensión estable. Como disolvente se ha emplea-do una mezcla 75:25 acetonitrilo:agua para favorecer la suspensión y formación de films uniformes de PNMPy/MoO3. El resto de condicio-nes de trabajo aparecen en trabajos previos [1,3]. La respuesta eléctrica de los films se ha caracterizado por voltamperometría cíclica (solución 0,1 M de LiClO4 en acetonitrilo), y se ha realizado el análisis morfológico (SEM) y micro- y nanotopográfico (AFM) de su superficie (Fig. 1). El análisis elemental EDX de los films ha probado la presencia de partículas de MoO3 en los films de PNMPy.

Fig. 1. Imágenes 3D de AFM de (a) PNMPy y (b) Nanocompuesto PNMPy/(10%) MoO3

Se ha constatado un aumento de la capacidad redox de almacenamiento de carga de los films de PNMPy, al formar el nanocompuesto por incorporación de las nanopartículas de MoO3. Este positivo efecto se ha relacionado con una mayor apertura de la superficie interfacial film-electrolito en el nano-compuesto, lo que está en concordancia con los resultados del análisis nanotopográfico.

Referencias:1. G. Fabregat, J. Casanovas, E. Redondo, E. Armelin y C. Alemán. Phys. Chem. Chem. Phys., 2014,16, 7850-7861.2. S. Ahmad y S. Singh. Electrochem. Commun., 2008, 10, 895-898.3. D. Aradilla, F. Estrany y Carlos Alemán. J. Phys. Chem. C, 2011, 115, 8430-8438

Agradecimientos:Los autores agradecen al MINECO la financiación recibida del Proyecto: MAT2015-69367-R.

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Tejidos de carbón activo modificados superficialmente con óxido de grafeno reducido y polímeros conductores. Estudio de su capacidad específica.Francisco Cases.

J. Fernández, J. Bonastre, J. Molina y F. Cases

Dep.de Ingeniería Textil y Papelera, Universitat Politècnica de València (Campus de Alcoy), Plaza Ferrándiz y Carbonell, s/n, 03801 Alcoy, España.

Este trabajo describe un proceso en dos etapas para conseguir el recubrimiento electroquímico de óxido de grafeno reducido (RGO) y polianilina (PANI) o polipirrol (PPY) sobre tejido de carbón activo (ACC), utilizando voltamperometría cíclica (CV). El hecho que los recubrimientos son realizados en dos pasos, el uno independientemente del otro, hace posible modificar las condiciones experimentales de cada uno de ellos y estudiar la respuesta electroquímica de RGO, PANI o PPY, separadamente. Así, modificando los límites de potencial de la reacción de polimerización de los polímeros conductores, ha sido posible observar la influencia de RGO y optimizar la cantidad máxima de polímero sobre la superficie del tejido de carbono activo y, así, en términos de capacidad específica mejorar la respuesta electroquímica del material. Las propiedades electroquímicas fueron caracterizadas mediante CV, curvas de carga y descarga galvanostáticas (usando configuraciones de célula de dos y tres electrodos) y la Espectroscopia de Impedancia Electroquímica (EIS). Una mejora máxima del 25 %, el 56 % y el 61 % sobre la capacidad inicial específica de ACC (aproximadamente 129 F g-1) fue obtenida para RGO, PANI y capas RGO-PANI, respectiva-mente. La respuesta en los procesos de carga y descarga conserva el 83 % de la capacitancia inicial después de 1000 ciclos. Los análisis de Espectroscopía Infrarroja por Transformada de Fourier y de Microscopía Electrónica de Barrido por Emisión de Campo (FESEM), permitieron caracterizar los distintos depósitos y la homogeneidad de éstos sobre la superficie del tejido. Estos análisis ayudaron a explicar los resultados electroquímicos.

Creemos que la metodología utilizada en este estudio abre una ruta para la preparación de materiales dimensionalmente versátiles, con una adecuada capacidad específica, una alta relación superficie/masa y volumen/masa, obtenidos mediante métodos electrodinámicos.

Figura 1. Curvas de carga y descarga medidas a una corriente de 1 A g-1 para muestras de tejido de carbón activo (ACC), tejido de carbón activo modifi-cado con óxido de grafeno reducido (ACC/RGO) y con RGO y PANI (ACC/RGO-PANI).

Agradecimientos:Se agradece la invitación y el apoyo económico por parte de la Red E3TECH (CTQ2015-71650-REDT) y de la Agencia Estatal de Investigación (AEI) y la European Union (FEDER funds) (contract MAT2016-77742-C2-1-P).

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Preparación y Estudio de Estabilidad Termodinámica y Electroquímica de Películas Superficiales de Fosfolípidos para la Administración y Liberación de Doxorubicina. Francisco Prieto.

Manuela Rueda1, Francisco Prieto1, María Luisa González-Rodríguez2, Antonio M. Rabasco2, Nabila Naithlo2, Marcos Vázquez1

1 Departamento de Química Física. Facultad de Química. Universidad de Sevilla. c/ Profesor García González 1. 41012. Sevilla. 2 Departamento de Farmacia y Tecnología Farmacéutica. Facultad de Farmacia. Universidad de Sevilla. c/ Profesor García González 2. 41012. Sevilla.

Las nuevas estrategias en la administración de medicamentos implican el uso de plataformas complejas, formadas por liposomas funcionalizados, como portadores hacia los tejidos diana. La estabilidad de estas vesículas depende en gran medida de los componentes de la bicapa lipídica y de las interacciones entre ellos [1].Además, los liposomas a menudo incluyen nanopartículas metálicas ancladas en su superficie, por lo que las interacciones con el metal también pueden afectar a la estabilidad del portador. Estos factores también pueden alterar las interacciones entre el lípido y el medicamento [2]. La doxorubicina (DOX) es un anticancerígeno con una elevada toxicidad y un tiempo de permanencia en flujo sanguíneo bajo. Para resolver ambos inconvenientes se están investigando nuevos métodos de administración del fármaco, incluyendo el uso de nanopartículas de oro (AuNPs) bioconjugadas.

En esta comunicación se presenta un estudio combinado en el que se realiza un análisis termodinámico de las isotermas de Langmuir de distintas mezclas lipídicas, seleccionado la formulación más estable para, posteriormente, estudiar “in vitro” el proceso de liberación del fármaco en formulaciones liposomiales cargadas con DOX.

Por otro lado, las películas lipídicas se han transferido mediante la técnica de Langmuir-Schaeffer a electrodos de oro Au(111), lo que ha permitido aplicar la metodología electroquímica para analizar la influencia que las interacciones con la superficie del oro y la presencia de un campo eléctrico tienen sobre la estabilidad de la película lipídica. El estudio electro-químico ha incluido también la reducción de DOX [3] sobre electrodos de oro, modificados con la película lipídica y sin modificar

References:1.- D. Christensen, D. Kirby, C. Foged, E.M. Agger, P. Andersen, Y. Perrie, H.M. Nielsen, “α,α-trehalose 6,6-dibehenate in nonphospholipid-based liposomes enables direct interaction with trehalose, offering stability during freeze-drying“, Biochim. Biophys. Acta, 1778, 1365–1373, 2008.2.- M.H. Ali, D.J. Kirby, A.R. Mohammed, Y. Perrie, “Solubilisation of drugs within liposomal bilayers: alternatives to cholesterol as a membrane stabilising agent”, J. Pharm. Pharmacol., 62, 1646–1655, 2010.3.- P. S. Guin, S. Das, P.C. Mandal, Electrochemical Reduction of Quinones in Different Media: A Review. International Journal of Electrochemistry, 1–22, 2011. https://doi.org/10.4061/2011/816202.

Efecto de mutaciones alejadas del centro redox sobre las transiciones ácida y alcalina de plastocianinas de cianobacterias Inmaculada Márquez.

I. Márquez1, J. L. Olloqui-Sariego1, E. Frutos-Beltrán2, M. A. De la Rosa2, J. J. Calvente1, A. Díaz Quintana2, R. Andreu1

1 Dpto de Química Física. Univ. de Sevilla. c/ Prof. García González 1. 41012 Sevilla, Spain.2 Instituto de Bioquímica Vegetal y Fotosíntesis. Univ.de Sevilla y C.S.I.C. Avd. Américo Vespucio 49. 41092 Sevilla, [email protected]

Las proteínas de cobre azul actúan como portadores de electrones en varios procesos celulares cruciales en plantas y bacterias. La mayoría de sus propiedades biofísicas son sensibles al pH debido a la presencia de grupos ácido/base ionizables en sus estructuras. En este sentido, algunos estudios han revelado que el pH induce cambios conformacionales que modu-lan su funcionalidad redox [1]. Por esta razón, el estudio del efecto del pH sobre su actividad redox y estabilidad es de gran interés para obtener información sobre su actividad fisiológica y para su uso en aplicaciones biotecnológicas.

En el presente trabajo, se ha estudiado por voltamperometría cíclica el impacto del pH en el equilibrio de intercambio electrónico entre un electrodo de oro modificado con cisteamina y las plastocianinas de la cianobacteria termófila Phormi-dium laminosum (Pho WT) y su variante mesófila de Synechocystis sp. PCC 6803 (Syn WT). Estas plastocianinas exhiben transiciones ácidas y alcalinas con diferencias en los valores de pKa. Las plastocianinas termófila y mesófila muestran un plegamiento y secuencia de aminoácidos idénticos en los alrededores del centro metálico, pero presentan diferencias sustanciales en la composición de la denominada “cara este", que es responsable de las interacciones con su pareja fisioló-gica [2]. Sobre esta base, se ha investigado también las consecuencias que tiene sobre la funcionalidad redox de estas proteínas la sustitución por mutagénesis de un residuo superficial localizado en esta región. Concretamente, se ha sustitui-do el aminoácido Phe80 por Alanina en Pho WT (Pho F80A) y el aminoácido Val48 en Syn WT por Isoleucina (Syn V48I). Se ha observado que dichas mutaciones modifican los valores de pKa correspondiente a las dos transiciones y que los valores pKa de Syn V48I se aproximan a los de la proteína termófila Pho WT.

Referencias:1. C. Dennison, Coord.Chem. Rev. 249 (2005) 3025–3054.2. M. J. Feio, A. Diaz-Quintana, J. A. Navarro, M. A. De la Rosa, Biochemistry 45 (2006) 4900–4906.

Agradecimientos:Los autores expresan su agradecimiento al Ministerio de Economía y Competitividad (MINECO) y al FEDER de la Unión Europea por la financiación de los proyectos CTQ2014-52641-P, CTQ2015-71955-REDT (ELECTROBIONET) y BFU2015-71017P. I. Márquez agradece al Ministerio de Economía y Competitividad (MINECO) la beca FPI BES 2015 071247.

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RGB Video Electrochemistry: Application to the characterization of passivated Ni/POT electrodes.Jerónimo Agrisuelas.

Jerónimo Agrisuelas, Jonatan Ávila, Alejandro Cuenca, Amparo Ferrer, José J. García-Jareño, Sara Lozano, Francisco Vicente

Physical Chemistry Department (University of Valencia), Dr. Moliner 50, 46100 Burjassor (Spain). E-mail: [email protected]

Ni electrodes were passivated by following a previously described procedure [1]. Poly (o-toluidine) (POT) was electrodeposited from a diluted monomer solutions in aqueous H2SO4 0.1 M solution on the surface of a passivated Ni electrode. Electrochemi-cal processes of POT involve anion exchange and color changes on the electrode surface that were monitored by in situ digital video recording[2]. The electrochemical response of this system shows a larger anodic peak during the first voltammogram and after peak currents are decreasing cycle by cycle. However, color changes on the electrode surface keep constant after 5 cyclic voltammograms (Figure 1). We found different rates of color change associated to the Red, Green and Blue channels. We also analyze the standard deviation for these three color channels observing large values at potentials near the maximum rate of color change. The color change of the electrode surface takes place non-homogenously observing some regions changing its color faster than other.

Figure 1. Change of color intensity against time during 5 voltammograms of a passivated Ni/POT electrode in a H2SO4 0.1 M aqueous solution.

References:[1] J. Gregori, J.J. García-Jareño, D. Giménez-Romero, F. Vicente, Growth of passive layers on nickel during their voltammetric anodic dissolution in a weakly acid medium, Electrochimica Acta. 52 (2006) 658–664. doi:10.1016/j.electacta.2006.05.051.[2] J. Agrisuelas, J.J. García-Jareño, E. Perianes, F. Vicente, Use of RGB digital video analysis to study electrochemical processes involving color changes, Electrochem. Commun. 78 (2017) 38–42. doi:10.1016/j.elecom.2017.04.001.

Acknowledgements:This work was supported by CICyT-FEDER project CTQ2015-71794-R.

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The electrochemistry of brominated guanine and cytosine at carbon based electrodes towards epigenetic sensing. Jesús Iniesta.

Andrés Noel Martín-Gómez1, Naiara Hernández Ibáñez1, Ignacio Sanjuan Moltó1, Thies Thiemann2, Vicente Montiel1, Jesús Iniesta1

1 Department of. Physical Chemistry.Institute of Electrochemistry, Faculty of Science, University of Alicante, PO box 03080, Alicante, Spain.2 Department of Chemistry, Faculty of Science, United Arab Emirates University, PO Box 17551,Al Ain, United Arab Emirates.

Pathophysiological disorders or cancer diseases are linked to genetic mutations or epigenetic modifications in DNA. One of the major epigenetic modifications corresponds to methylation of DNA, particularly methylation of guanine and cytosine nucleic bases. Although the role of DNA methylation is not fully understood, it is known that one of its main functions is the control of gene expressions. However, hypermethylation of the CpG islands is associated with some diseases, including carcinomas, leukemia, and lung cancer, among many others. On the other hand, the participation of radical species that mediate through inflammatory events of cellular tissues can give rise to the formation of halogenated nucleic bases such as bromoguanine (Br-G) and bromocytosine (Br-C).

This communication aims at, for the first time, the electrochemical behavior of Br-G and Br-C at different carbon materials using cyclic voltammetry and pulse techniques. Glassy carbon, graphite and boron doped diamond electrodes are first chosen for a comparative study and then compared to graphene and carbon nanotubes materials of different nature and surface chemistry. The simultaneous determination of Br-G or Br-C in the presence of other nucleic bases, such as 8-oxogua-nine, guanine, adenine or cytosine, is also addressed for analytical sensing applications.

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Novel ZnO/ZnS heterostructures synthetized by electrochemical anodization under controlled dynamic conditions in glycerol based electrolytes.José García-Antón.

Rita Sánchez-Tovar, Ramón M. Fernández-Domene, Bianca Lucas-Granados, Maria Teresa Montañés, Arturo Sanz-Marco, José García-Antón

Ingeniería Electroquímica y Corrosión, Instituto Universitario de Seguridad Industrial, Radiofísica y Medioambiental, Universitat Politècnica de Valè[email protected]

Photocatalysts made of titanium dioxide (TiO2) are gaining special attention due to its outstanding properties. On the other hand, zinc oxide (ZnO) is also an n-type-wide band gap semiconductor (3.37 eV) with similar characteristics as TiO2 but with the advantage that ZnO possesses a higher electron mobility (from 10 to 100 times higher in comparison to TiO2). However, one of the main drawbacks of using ZnO as photocatalyst is its rapid recombination of the photogenerated electron–hole pairs, which makes considerably low its photocatalytic efficiency. In order to overcome this issue, in this work it is proposed the use of hybrid semiconductors systems which might promote the separation of electron–hole pairs and retain reduction and oxidation reactions at two different sites. In particular, this work is focused on ZnO/ZnS heterostructures due to the good photocatalytic behavior of ZnS; that is, its rapid electron–hole pairs generation together with a higher negative reduction potential of the excited electron. In fact, ZnO/ZnS heterostructures could reduce the recombination rate of the charge carriers owing to their separated band gaps.

The objective of this study is the synthesis of ZnO/ZnS heterostructures by electrochemical anodization under stagnant and stirring conditions in Na2S/NH4F glycerol based electrolytes. The influence of glycerol as well as the effect of Na2S concentration was evaluated. The morphology of the heterostructures was characterized using field emission scanning electron microscopy (FE-SEM) with EDX and their crystallinity with Raman spectroscopy. The final purpose of this work is to study the photocatalytic behavior of the formed ZnO/ZnS heterostructures for hydrogen production by photoelectrochemical water splitting.

The obtained results showed that the hydrodynamic conditions promoted an ordered nanotubular morphology which facilita-tes electron–hole separation and consequently, the photoelectrochemical activity for water splitting is enhanced. Additionally, the effect of glycerol in the anodization solutions seems to be beneficial for increasing the dark current photostability.

Acknowledgements:Authors thank for the financial support to the Ministerio de Economía y Competitividad (Project Code: CTQ2013-42494-R), for its help in the Laser Raman Microscope acquisition (UPOV08-3E-012), for the co-finance by the European Social Fund and for the financial support from the Spanish excellence network E3TECH funded by the Ministerio de Economía y Compe-titividad (MINECO) under project CTQ2015-71650-RD and to the UPV (PAID-10-16-SP2016-0026) for the Postdoctoral Contract.

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Towards the determination of [Sb(OH)3] with AGNES Josep Galceran.

Pepita Pla-Vilanova1, Josep Galceran1*, Encarna Companys1, Montserrat Fliella2, and Jaume Puy1

1 1Dep. Química, Universitat de Lleida & AGROTECNIO, Av. Rovira Roure 191, 25198 Lleida (Catalonia).2 Institute F.-A.Forel, University of Geneva, Boulevard Carl-Vogt 66, CH-11205 Geneva, (Switzerland).*E-mail contact: [email protected]

AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) is an electroanalytical technique that, when using mercury electrodes, can be applied to metals that form an amalgam and whose redox process in solution takes place at more negative potentials than the ones where Hg reoxidates. This technique has already been used for the determination of free-cation concentration of Zn, Cd, Pb, In and Sn in a variety of systems (seawater, river water, soil extracts, dispersions of nanoparticles, etc.)[1]. Sb(III) fulfils the conditions of amalgamation and suitable redox potential. However, hydrolysis is so prevailing that species such as Sb(OH)3 and Sb(OH)2+ are dominant in solution even at acidic pH values, while the standard determinand for AGNES (the free Sb3+) has not been described. On the other hand, there is a huge number of unresolved questions around Sb(III) speciation[2].

This work aims at determining Sb(OH)3 concentrations directly with AGNES. Promising preliminary results have been obtained, such as the stabilization of the signal (for longer deposition times) indicating the fulfilment of equilibrium, and the Nernstian proportionality between applied potential and charge of the equilibrated signal (see figure 1). In addition, we found a good correlation between concentrations experimentally determined at pH = 3 and pH = 2 and the prediction from VMINTEQ. Some challenges are being tackled, such as the lack of accurate values of the peak potential of Differential Pulse Polarograms. Another challenge is the low solubility of Sb0 in the mercury amalgam, which is being overcome with the use of larger electrodes which can provide charges safely above the limit of detection, before the onset of the decay of the signal (see highest gain or preconcentration factor Y in figure 1).

Figure 1. Stabilization or decay of AGNES signal.

References:1.- Galceran, J.; Lao, M.; David, C.; Companys, E.; Rey-Castro, C.; Salvador, J.; Puy, J. The impact of electrodic adsorption on Zn, Cd or Pb speciation measurements with AGNES. J. Electroanal. Chem. 2014, 722-723, 110-118.2.- Filella, M.; Williams, P.A.; Belzile, N. Antimony in the environment: knowns and unknowns. Environ. Chem. 2009, 6, 95–105.

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Adsorción de compuestos quinolínicos sobre nanotubos de carbono de pared múltiple (MWCNT). Estudios espectroscópicos y electroquímicos.Juan Daniel Mozo.

J. Carbajo1, E. Gutierrez-Álvarez1, J.J. Maraver1, J.D. Mozo1

1 Laboratorio de Electroquímica Aplicada. Facultad de Ciencias Experimentales. Universidad de Huelva. Avda. 3 de Marzo s/n, Campus de El Carmen, 21071 Huelva (España).

Los compuestos quinolínicos estudiados: 1,4-antraquinona 9,10-antraquinona, naftoquinona y benzoquinona poseen una alta aromaticidad y son susceptibles de adsorberse en mayor o menor medida sobre nanoestructuras de carbono con un gran sistema de electrones π como los nanotubos de carbono. La electroquímica de estos compuestos se ha estudiado extensamen-te, ya que forman pares redox muy reversibles y tienen aplicación en la fabricación de supercondensadores, aunque el estudio de su adsorción sobre superficies de carbón es muy escaso [1,2].

Para el estudio de su adsorción se han preparado suspensiones de MWCNT en alcohol etílico a las que se añaden diferentes concentraciones de compuesto quinolínico. Mediante la absorción UV característica de estos compuestos en medio alcalino, una vez retirados los nanotubos por centrifugación, se determinan las cantidades adsorbidas y se analizan las características del proceso superficial en equilibrio.

Los resultados espectroscópicos se complementan con estudios electroquímicos realizados sobre electrodos de carbono glassy modificados superficialmente con MWCNT como se describe en la bibliografía [3]. Estos electrodos se sumergen durante un periodo de tiempo determinado en una disolución patrón de quinona y luego se someten a un barrido de potenciales mientras están sumergidos en una disolución acuosa tamponada. Las intensidades de pico registradas proporcionan información sobre la cantidad de quinona adsorbida en el electrodo, y su evolución en el tiempo sobre la estabilidad de dicha adsorción. Se ha estudiado la influencia del pH y del tiempo de acumulación sobre el equilibrio de adsorción de cada uno de los compuestos quinolínicos.

Los resultados obtenidos muestran que cuanto más extenso es el sistema π de la molécula de quinona, más cantidad es retenida por adsorción y más estable es dicha adsorción en el tiempo. Se han incluido en el estudio dos isómeros de antraqui-nona para analizar la influencia de otros parámetros relacionados con la estructura molecular sobre la adsorción de estos compuestos.

Referencias:1. Shi K, Shiu K-K. Adsorption of some quinone derivatives at electrochemically activated glassy carbon electrodes. J Electroanal Chem. 2004;574(1):63-70. doi:10.1016/j.jelechem.2004.07.027.2. Kim H-J, Han Y-K. How can we describe the adsorption of quinones on activated carbon surfaces? Curr Appl Phys. 2016;16(10):1437-1441. doi:10.1016/j.cap.2016.08.009.3. Moscoso R, Carbajo J, Squella JA. 1,3-Dioxolane: A green solvent for the preparation of carbon nanotube-modified electrodes. Electrochem commun. 2014;48:69-72. doi:10.1016/j.elecom.2014.08.019.

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Characterization of Na-based cathode materials by solid state NMR. Juan Miguel López del Amo.

Elena Gonzalo1, Frederic Aguesse1, Nagore Ortiz1, Begoña Acebedo1, Nicholas Drewett1, Guillermo Liendo1, Gurpreet Singh1, Montse Galceran1, Teófilo Rojo1,2, Juan Miguel López del Amo1.

1 CIC Energigune, Albert Einstein 48, 01510 Vitoria-Gasteiz (Basque Country).2 Departamento de Química Inorgánica, Universidad del País Vasco UPV/EHU.

The search for commercially viable batteries based in sodium, demands that new electrode materials and electrolytes are found and optimized, in order to obtain batteries that are more economic, safer, and with a longer life. One of the most promising family of cathode materials for Na-ion batteries are the NaMO2 layered oxides (M = Cr, Mn, Fe, Co, Ni, etc. and mixtures of 2-3 transition metals) because of their high capacity and structural simplicity (1,2). Solid-state NMR spectra of such materials are challenging due to the large paramagnetic interactions induced by the transition metal ions in the nuclei under observation (23Na in the present work). These compounds can induce huge shifts of the NMR resonances of up to several thousands of ppm, especially when strong paramagnetic ions are involved like Fe3+ or Mn3+ (3).

We will show in this presentation, some recent work carried out in our laboratory where fast MAS NMR (>50 kHz) in combi-nation with low fields where successfully applied, in order to obtain very valuable information about the structure and the ionic mobility in this family of materials. Furthermore, we will show how, ex situ solid-state NMR has been used as a tool to understand the structural transitions that undergo during the sodiation/desodiation processes present during electrochemi-cal cycling.

In particular, the impact of Fe2+, Mg2+, Zn2+, Ti4+, H+ and other dopants on the local structure and dynamics of Na+ in Na-ba-sed layered oxides was followed by 23Na solid state NMR. The information obtained is related to the performance of the materials providing a useful tool to rationalize the effects of different dopants on the electrochemistry.

References:1. M. H. Han, et al. Energy Environ. Sci., 2015, 8, 81-1022. N. Yabuuchi, et. al Electrochemistry, 2012, 80, 716-7193. G. Singh, et. Al Journal of Materials Chemistry A. 2015 13 - 3, 6954 - 6961

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Strategies to improve the electrochemical performance of a Na manganese-based layered oxide.Laura Acebo.

L. Acebo,1* E. Gonzalo,1 M. Galceran1 and T. Rojo.1,2

1 CIC energiGUNE, Albert Einstein 48, 01510 Vitoria-Gasteiz, Spain.2 Departamento de Química Inorgánica, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU) Barrio Sarriena s/n, 48940 Leioa - Bizkaia, Spain.*[email protected]

Sodium-ion batteries (SIBs) have generated considerable interest in these last decades with respect to developing sustainable and low-cost electrical energy storage systems. The high abun-dance of Sodium (Na) with a good geographical distribution and the low cost of sodium resources make Na-ion batteries an especially promising alternative to Lithium-ion batteries (LIBs) for large scale applications.[1,2]

Among the Na-ion cathode candidates, layered oxides with NaxMO2 (M = Ti, Cr, V, Mn, Fe, Co, Ni, or combinations of the transition metals) chemical formula have been identified as excellent cath-ode materials for SIBs due to their outstanding electrochemical performances (high capacity and high intercalation voltages) and scalable synthesis in most cases.[3,4] They are composed of repeating sheets of MO6 layers with Na ions being sandwiched in between the oxide layers and may exhibit dif-ferent structures depending on the various oxygen stacking ordering which are designated with a letter and a number. The letter indicates the Na environment (P: prismatic and O: octahedral), and the num-ber the stacking order: 2 corresponds to -ABBA- and 3 to -ABCABC- oxygen stacking.

During the last years, several sodium manganese based layered oxides have been studied by our group, mainly partially sodiated (x= 2/3) P2- phases, due the versatility of Mn. Manganese is a low cost and environmentally friendly element with several oxidation states (although the most common is Mn3+/Mn4+).

As a representative example, Na2/3Mn0.8Fe0.1Ti0.1O2, the positive effect that Ti has on the elec-trochemical performance of the material minimizing the slab gliding upon cycling, has been evaluated. P2-Na2/3Mn0.8Fe0.1Ti0.1O2 phase shows excellent electro-chemical properties even at high current rates; 99.40 mA·h·g-1 as reversible specific capacity at 1C in the first cycle and 87.17 mA h g-1 at the 300th cycle with 87.70% of capacity retention.[5]

In this work, we will present the effect that the reduction of the particle size and the microstruc-ture on P2-Na2/3Mn0.8Fe0.1-

Ti0.1O2 material via ball milling has on its electrochemical performance (i.e. capacity retention, coulombic efficiency…). The material will be synthesized by solid state. The char-acterization will be carried out by scanning electron microscopy (SEM) together with an energy-dispersive X-ray spectroscopic detector (EDS), X-Ray diffraction (XRD) and galvanostatic electro-che-mical tests.[6]

References:1. V. Palomares, et al., Energy Environ. Sci. 2012, 5, 5884.2. V. Palomares, et al., Energy Environ. Sci., 2013,6, 2312.3. M. H. Han, et al., Energy Environ. Sci. 2015, 8, 81-102.4. N Ortiz- Vitoriano el al., Energy Environ. Sci. 2017 DOI 10.1039/C7EE00566K.5. M. H. Han, et al., Chem. Mater. 2016, 28, 106−116.6. L. Acebo et al., Paper in preparation.

Solid-phase synthesis of imprinted nanoparticles as high affinity recognition elements for chiral sensing.Mª. Aránzazu Goicolea.

Alberto Gómez-Caballero, Deiene Garcia-Mutio, Nora Unceta, M. Aránzazu Goicolea, Ramón J. Barrio

Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country UPV/EHU, 01006 Vitoria-Gasteiz, Spain.

Molecular imprinting offers the possibility of developing artificial receptors capable of being used for sensor construction. This technique lies in the synthesis of high cross-linker polymers in the presence of a template molecule responsible for imprinting molecular cavities in a three-dimensional polymer matrix during the synthesis procedure. These cavities are complementary in shape, size and function-ality to the template itself, providing the polymer with selective recognition capability. In many instanc-es, this recognition shows affinities comparable to those of natural receptors such as antibodies, en-zymes or other proteins, having surpassed it in some cases; especially when the recently emerged solid-phase imprinting approach is employed for the development of the imprinted material [1,2].

Solid-phase synthesis of molecularly imprinted polymers (MIP) is based on the immobilisation of the template on a solid support (glass beads) instead of being free in the polymerisation medium. Thereaf-ter, polymerisation is initiated by UV energy in the presence of an iniferter, performing a reversible deactivation radical polymerisation (RDRP). RDRP is crucial to get nanoparticles with homogeneous size distribution, obtaining in this regard materials with very low polydispersity, what may avoid usual binding site heterogeneity shown by MIPs synthesised under conventional techniques. The benefits that these high affinity materials provide have been exploited in sensor construction minimising cross-reactivity, thereby obtaining sensors with remarkably higher selectivity [3,4].

In the work presented here, high affinity MIP nanoparticles have been immobilised on gold microe-lectrodes to construct miniaturised devices for chemical impedimetric sensing. To this end, properly cleaned gold fibers have been modified with self-assembled monolayers of cysteine and next high affinity nanoparticles have been grafted to the terminal amine group of the aminoacid through car-bodiimide coupling chemistry. The fabricated sensor was applied to the impedimetric detection of the S enantiomer of the drug citalopram obtaining remarkable chiral selectivity over the R enantiomer with a sensitivity of 4.49 x104 Ω decade-1. Measured electrochemical signals were repeatable, obtaining RSD values below 14% with a single sensor and below 15% using different sensors at two concentra-tion levels of the target analyte (10-8 and 10-6 M).

References:1. F. Canfarotta, A. Poma, A. Guerreiro and S. Piletsky, Nat. Protoc., 2016, 11, 443-455.2. A. Poma, A. Guerreiro, M. J. Whitcombe, E. V. Piletska, A. P. F. Turner and S. A. Piletsky, Adv. Funct. Mater., 2013, 23, 2821-2827.3. I. Basozabal, A. Guerreiro, A. Gomez-Caballero, M. A. Goicolea and R. J. Barrio, Biosens. Bioelectron., 2014, 58, 138-144.4. D. Garcia-Mutio, A. Gomez-Caballero, A. Guerreiro, S. Piletsky, M. A. Goicolea and R. J. Barrio, Sens. Actuators, B, 2016, 236, 839-848.

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Comparison of electrochemical and spectropho-tometrical methods for the determination of antioxidant capacities of healthy food components. María Pilar Rivas Romero.

María Pilar Rivas Romero1, Rafael Estévez Brito1, Mercedes Ruiz Montoya2, José Miguel Rodríguez Mellado1, Rafael Rodríguez-Amaro1, José Luis Ávila Manzano1.

1 Departamento de Química Física y Termodinámica Aplicada. Facultad de Ciencias.CeiA3, IUIQFN, Campus Universitario Rabanales, edificio Marie Curie. Universidad de Córdoba. E-14014-Córdoba (Spain).2 Departamento de Ingeniería Química, Química Física y Ciencias de los Materiales. Facultad de Ciencias Experimentales. Campus de “El Carmen”. Universidad de Huelva. E-21071- Huelva (Spain).

The antioxidant capacity of natural samples has been determined by different methods that can be classified as HAT (hydro-gen atom transfer), ET (electron transfer) and mixed HAT-ET methods.[1] Electrodes modified with the conducting polymer poly-neutral red and electrodeposited platinum nanoparticles were also proposed [2].

The antioxidant capacity of 17 active principles present in foods is determined by using two sets of methods (see table): i) spectrophotometric, DPPH radical scavenging method (ARP) and CUPRAC assay; ii) electrochemical, using a mercury electrode (Hg) and a glassy carbon electrode covered with poly-neutral red and doped with Pt nanoparticles (PNR). This last electrode assesses the scavenging activity of the antioxidants, improving the measurement time and easiness respect to the rest of the methods. Compared to Hg electrode, the measurements are made in conditions close to the physiological conditions (pH 7, aqueous medium). Using this sensor, antioxidants without activity in the DPPH radical scavenging assay can be studied. With respect to CUPRAC, the advantages of the modified electrode are the absence of organic solvent, with the consequent closeness to physiological conditions, and the lower measuring time involved. The sensitivity of this sensor is comparable to those of DPPH and CUPRAC.

Table 1. Antioxidant capacities in mmol–1 (ARP) and Trolox equivalents (rest).

References:1. R. Apak, M. Özyürek, K. Güçlü and E. Çapanoğlu, J. Agric. Food Chem. 64 (2016) 997; 64 (2016) 1028; 64 (2016) 10462. P. Rivas and J. M. Rodríguez Mellado, Electrochim. Acta 171 (2015) 150

Acknowledgements: Financial support from the XXI Own Research Program of the University of Córdoba and the Operative Funding FEDER-An-dalucía Program

Antioxidant ARP CUPRAC Hg PNR 2,4-dihydroxybenzaldehyde 0 0.41 1.79 0.206 2,5- dihydroxybenzaldehyde 17.5 1.56 1.01 0.488 3-hydroxycoumarin 0 2.41 2.21 0.806 4-Hexylresorcinol 2.3 2.26 1.72 0.425 Ascorbic acid 6.4 1.73 -- 1.09 Cinnamic acid 0 0.0005 0.59 0.313 Gallic acid 12.5 2.97 3.05 0.95 Carvacrol 0.1 1.39 1.59 0.569 Cinnamaldehyde 0 0.1 1.47 0.475 Eugenol 5 3.04 2.29 0.738 Geraniol 0 0.01 0.37 0.25 Limonene 0 0.003 0.21 0.188 Salicylaldehyde 0 0.05 0.52 0.288 Sesamol 5.5 0.87 0.52 0.675

-pinene 0 0.04 0.38 0.125 Thymol 0.8 2.08 0.81 0.681 Vanillin 0.1 0.43 0.79 0.494

Use of complementary techniques in characterization of carbon supports for PEMFC.Maialen Sánchez.

M. Sánchez1, A. R. Pierna1, A. Lorenzo1, I. Gómez2, D. Cazorla3, J. J: del Val4

1 Department of Chemical and Environmental Engineering, School of Engineering of Gipuzkoa, University of the Basque Country UPV/EHU, Plaza Europa 1, 20018 Donostia-San Sebastián. 2 Department of Thermal Engines and Machines, School of Engineering of Gipuzkoa, University of the Basque Country UPV/EHU, Plaza Europa 1, 20018 Donostia-San Sebastián. 3 Department of Inorganic Chemistry, University of Materials Institute, University of Alicante UA, Apartado de Cor-reos 99, 03080 Alicante4 Materials Physics Department, Faculty of Chemistry, Paseo Manuel Lardizabal 3, 20018 Donostia-San Sebastián.

Currently, the polymer exchange membrane fuel cell (PEMFC) is one of the most promising fuel cell technologies for transport and stationary applications. One of the challenges facing the com-mercialisation of PEMFCs is the high cost they exhibit. The major approach to reducing their cost is to focus on the development of less expensive and high performing fuel cell compo-nents. Amorphous carbon such as black carbon Vulcan XC-72R has been the traditional support used in fuel cells since it offers high surface area in addition to its availability and low cost [1].The goals of this work were two-fold. Firstly, to prepare an activated carbon support and characterize its textural properties using vari-ous complementary techniques: nitrogen adsorp-tion and mercury intrusion porosimetry. Secondly, to study its performance as a catalyst support for the anode catalyst layer in a PEMFC and compare it to a commercial glassy carbon support. In this work, a carbon black Vulcan® XC-72R was chemically activated [2]. Its textural characteristics were studied by nitrogen physical adsorption, mercury-intrusion porosimetry (MIP) and scanning electron microscopy (SEM). Preparation of MEAs for the anode catalytic layer was carried out using the activated carbon support and a metallic amorphous electrocatalyst Ni59Nb40Pt0.6Fe0.4, whereas a commercial Pt/C catalyst was applied on the cathode side. Finally, the MEAs were tested in a PEMFC station. The results showed that the characterization techniques applied to the supports were complementary. The nitrogen adsorption method yielded data on the micro and mesopore structure and the mercury porosimetry provided supplementary infor-mation outside the measuring range of nitrogen adsorp-tion. The PEMFC tests showed that the MEAs containing the activated carbon produced a higher power output than that of the glassy carbon.

References:1. N. Mansor; T. S. Miller; I. Dedigama; A. B. Jorge; J. Jia; V. Brázdová; C. Mattevi; C. Gibbs; D: Hogson; P. R. Shearing; C. A. Howard. Graphitic Carbon Nitride as a Catalyst Support in Fuel Cells and Electrolyzers. Electrochimica Acta 222 (2016) 44-57 2. M. M. Antxustegi, A. R. Pierna, N. Ruiz. Chemical Activation of Vulcan® XC72R to be used as support for NiNbPtRu catalysts in PEM fuel cells. International Journal of Hydrogen Energy 39 (2014) 3978-3983

Acknowledgments: The authors gratefully acknowledge the financial support to the University of the Basque Country UPV/EHU for the Project EHUA 15/12.

148

149

Reducción y modificación química de grafeno en un solo paso para el desarrollo de plataformas electrocatalíticas.Mónica Revenga.

I. Bravo1,2, M. Revenga-Parra1,2,3, F. Pariente1,3, E. Lorenzo1,2,3*

1 Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, 28049 Madrid (Spain).2 IMDEA-Nanoscience. Faraday 9, Campus Cantoblanco-UAM, 28049 Madrid (Spain).3 Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid (Spain).

El grafeno es un nanomaterial que despierta mucho interés debido a sus propiedades físicas y químicas únicas y sus potenciales aplicaciones. Es por ello que existe un gran interés en desarrollar estrategias para la producción de grafeno a gran escala. El método de síntesis más habitual del grafeno se basa en la reducción de óxido de grafeno, cuya obtención es sencilla a partir de la oxidación de grafito. El óxido de grafeno presenta una baja conductividad eléctrica debido a que el sistema π-conjugado se encuentra alterado. Esta conductividad se puede recuperar mediante la restauración de la red π, de ahí el interés por la reducción del grafeno oxidado. Este paso de reducción se realiza generalmente mediante métodos químicos que emplean agentes reductores, como la hidroquinona [1].

Por otro lado, la modificación de la superficie de grafeno con moléculas activas permite modular sus propiedades, y dotarle de funciones que puedan aumentar sus aplicaciones en el futuro. En este sentido, con el fin de mejorar sus propiedades electroca-talíticas, el grafeno puede ser funcionalizado con moléculas electroactivas. Entre estas moléculas electroactivas, en el presente trabajo se ha elegido N,N’-bis(3,4-dihidroxibencilideno)-1,2-diaminobenceno (3,4-DHS), un ligando de base de Schiff polihidroxilado que tiene una doble función: reductor y modificador. El 3,4-DHS contiene dos grupos de hidroquinona que pueden reducir el óxido de grafeno y también un anillo aromático que puede interactuar de manera no covalente con los carbonos sp2 del grafeno. Además, muestra propiedades electrocatalíticas reduciendo el sobrepotencial de oxidación de la hidracina [2]. El óxido de grafeno reducido y modificado con 3,4-DHS obtenido (rGO-DHS), se ha caracterizado mediante diferentes técnicas espectroscópicas y electroquímicas. Además, se ha depositado sobre la superficie de electrodos serigrafia-dos de carbono, obteniéndose electrodos modificados con películas electroactivas de rGO-DHS, que presentan actividad electrocatalítica frente a la oxidación de hidracina.

Referencias:1. Wang, G. X.; Yang, J.; Park, J., Gou, X. L.; Wang, B.; Liu, H.; Yao, J. J. Phys. Chem. C 2008, 112, 8192-8195.2. Revenga-Parra, M.; Lorenzo, E.; Pariente, F. Sens. Actuators B 2005, 107 678–687.

150

A composite polymer electrolyte based on Poly (vinylidene Fluoride) and Poly (vinyl Alcohol) for Lithium-Ion batteries. Pilar Ocón.

M. Borràs1, D. Mata1, J. C. Pérez-Flores2, P. Ocón1

1 Universidad Autónoma de Madrid, Dpto. Química Física Aplicada, C/ Francisco Tomás y Valiente 7, 28049, Madrid, Spain.2 Universidad CEU San Pablo, Dpto. Química, Urb. Montepríncipe, Boadilla del Monte, 28668, Madrid, Spain.

Lithium ion batteries (LIBs) have reached a great development in the last years as the current energy storage for portable devices such as laptop computers, cell phones…[1]. Moreover, LIBs with large capacity are promising power sources for both hybrid and pure electric vehicles [2].

Poly(vinylidene fluoride), PVDF, and its copolymer Poly(vinylidene fluoride-co-hexafluoropropylene), PVDF-co-HFP have been extensively studied as a polymer matrices, because their excellent chemical resistance and thermal stability. However, their application is currently limited because their poor mechanical strength [3]. In general, PVDF polymer exhibits attractive properties as host matrix for Li+ ions and good electrochemical stability due to the presence of strong functional C-F groups. Furthermore, its high dielectric constant facilitates the Li salt dissolution and in consequence support high charge carried concentrations [4].

On the other hand, some applications take advantage of the hydrophilic nature of polyvinyl alcohol polymer, PVA. Some authors reported the miscibility of PVA in PVDF with a high degree of intermolecular interactions between both polymers [5]. Taking into account these previous results, we explore a systematic study of the PVA-PVDF blending procedure and its application as electrolyte in LIBs batteries.

In this work, we synthesize PVDF-PVA blended membranes with different weight ratios (5:1, 3:1 and 1:1), with and without LiClO4 salt (5 %) by doping them before the membrane casting process. Morphology, spectroscopic and thermal characteri-zation were carried out by SEM, FTIR and TGA- DSC. An ionic conductivity as high as 4·10-3 S/cm at 40ºC was obtai-ned by electrochemical impedance spectroscopy. This figure encouraged us to evaluate these membranes as solid electrolyte for LIBs. The electrochemical charge/discharge cycling performance was studied using LiFePO4 composite cathode in a semi-cell configuration and its functionality compared with Celgard 2325 as reference separator. Studies in a full lithium-ion cell are in progress.

References:1. J. M. Tarascon, M. Armand, Nature 2008, 414, 359-367.2. A. Opitz, P. Badami, L. Shen, K. Vignarooban, A. M. Kannan, Renew. Sust. Energ. Rev. 2017, 68, 685-692.3. V. D. Noto, S. lavina, G. A. Giffin, E. Negro, B. Scrosati. Electrochimica Acta, 2011, 57,4-134. H.-C. Shiao, D. Chua, H. Lin, S. Slane , M. Salomon. Journal of Power Sources 87 2000 167–1735. J. Mijovic, J. W. Sy, T. K. Kwei. Macromolecules, 1997, 30, 3042-3050.

151

Electrochemical Degradation of Atenolol with Boron-Doped Diamond Electrodes.Valentín Pérez-Herranz.

A. N. A. Heberle1,2, V. Pérez-Herranz1, E. Ortega1, M. García-Gabaldón1, A. M. Bernardes2

1 Grupo IEC. ISIRYM, Universitat Politècnica de València. Camino de Vera S/N, 46022 Valencia (Spain).2 Departamento de Materiais, PPGE3M, Universidade Federal do Rio Grande do Sul. Avenida Bento Gonçalves, 9500, Porto Alegre (Brazil).

In the last decades, the consumption of medicines has been increased considerably, consequently the presence of such compounds in surface water has risen up as well. One of the most consumed drugs is the Atenolol (ATN), a β-blocker, applied in the treatment of hypertension, angina pectoris, and cardiac arrhythmias. The human body metabolism just absorbs around 50% of the ATL taken dose, which means that half of the amount goes into the environment. Among the β-blockers, ATL is the most toxic to humans and aquatic organisms. Also, ATL was reported to be very stable to UV radiation and its half time life in pure water was found to be higher compared to others β-blockers [1]. Hence the removal of ATL is essential, mainly to minimize the environmental degradation. In this way, ATL removal by anodic oxidation (AO) using boron-doped diamond (BDD) is a promising technology [2]. The BDD electrodes are chemically stable and present a large potential window when compared to other semiconductor oxides electrodes. In BDD surface, the degradation of the organic molecules can be basically conducted by two ways, direct and/or indirect oxidation. In the direct oxidation, the organic molecule changes electrons directly with the electrode surface. In the indirect oxidation, the organic matter interacts with the generated oxidant radicals, mainly hydroxyl radical (•OH) [3]. This study investigates the effect of the applied current intensity in the ATL degradation, driven by AO, in a recirculation bath reactor with 1 L capacity. The anode was a BDD (74 cm2), supported by a Niobium matrix and the cathode was a stainless-steel plate (74 cm2). A working solution was prepared containing 100 mg L-1 of ATL and 2 g L-1 of Na2SO4 as supporting electrolyte. The flow rate was 60 L h-1. Samples were collected, and ATL degradation was followed by Ultraviolet/visible (UV/Vis) spectroscopy and by chemical oxygen demand (COD). Based in preliminary results, it can be concluded that the ATL degradation and oxidation rates increase with the applied current density. The reaction rate showed a first order kinetics, which not lead to the complete oxidation to CO2.

References:1. N. Vieno, T. Tuhkanen, L. Kronberg, Elimination of pharmaceuticals in sewage treatment plants in Finland, Water Res. 41 (2007) 1001–1012.2. E. I. Chávez, R. M. Rodríguez, P. L. Cabot, F. Centellas, C. Arias, J. A. Garrido, E. Brillas, Degrada-tion of pharmaceutical beta-blockers by electrochemical advanced oxidation processes using a flow plant with a solar compound parabolic collector, Water Res. 45 (2011) 4119-4130.3. M. Panizza, G. Cerisola Application of diamond electrodes to electrochemical processes, Electro-chim. Acta, 51 (2005), pp. 191–199.

Aknowledgements:The authors thank the financial support from MINECO (Ministerio de Economía y Competitividad, Spain) under project CTQ2015-65202-C2-1-R, co-financed with FEDER funds, and to the Spanish excellence network E3TECH, project CTQ2015-71650-RDT.

152

Coupling of electrocoagulation with electrochemical advanced oxidation processes for the removal of benzophenone-3. Zihong Ye.

Zihong Ye, Enric Brillas, Pere L. Cabot, Francesc Centellas, Ignasi Sirés

Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona.

Benzophenone-3 (BP-3) is a relevant environmental pollutant since it is an active ingredient widely present in sunscreen lotions and personal care products (PCPs), therefore entering all kinds of water including urban wastewater, lakes and rivers, as well as sediments, fish and even human milk. It has been proven that BP-3 acts as an endocrine disruptor, genotoxicants and carcinogen [1].BP-3 is quite persistent in natural environments and thus, the parent compound and its toxic metabolites end in wastewater treatment plants [2].

Here, a recently reported electrochemical system consisting in an electrocoagulation (EC) pre-treatment and subsequent application of an electrochemical advanced oxidation process (EAOP), such as electro-oxidation (EO), electro-Fenton (EF) or photoelectro-Fenton (PEF), has been applied for degrading BP-3 in a real wastewater matrix collected from the primary decanter of a municipal plant. EC process not only acted as a phase separation process, but it was also a transformation technology able to yield breakdown by-products. Key parameters like anode material (Fe and Al), current density, suppor-ting electrolyte, initial BP-3 concentration and connection mode have been assessed during the individual EC process with simulated wastewater. A greater removal of both, total organic carbon (TOC) and BP-3, was obtained using Al anode, which can be explained by the contribution of precipitation as solution pH decreases during the electrolysis. Considering the low BP-3 concentration and pH in real wastewater, the Fe-Fe system was finally adopted in EC, reaching ca. 40% BP-3 removal along with the accumulation of a small amount of Fe3+/Fe2+ catalyst.

A BDD or DSA anode and an air-diffusion cathode, both of 3 cm2, were employed to perform various single EAOPs. In all cases, BP-3 was totally degraded within the first hour of treatment, achieving the highest TOC removal (77.5%) in PEF process due to the enhanced formation of •OH in the bulk. On the other hand, two-step EC/EAOPs (EF or PEF) treatments were performed to treat BP-3 in real wastewater, with an evident upgrade of mineralization rate. The main reaction by-pro-ducts accumulated in the different systems were identified by GC-MS.

References:1. C.A. Downs, E. Kramarsky-Winter, R. Segal, J. Fauth, S. Knutson, O. Bronstein, F.R. Ciner, R. Jeger, Y. Lichtenfeld, C.M. Woodley, P. Pennington, K. Cadenas, A. Kushmaro, Y. Loya, Arch. Environ. Contam. Toxicol. 70 (2016) 265–288.2. Y. Li, X. Qiao, C. Zhou, Y.N. Zhang, Z. Fu, J. Chen, Chemosphere 153 (2016) 494-499.

Acknowledgments:Financial support from project CTQ2016-78616-R (AEI/FEDER, EU), as well as from excellence network E3TECH under project CTQ2015-71650-RDT (MINECO, Spain) and from the PhD grant awarded to Z.H. Ye (CSC, China) is acknowledged.

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