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Hindawi Publishing CorporationThe Scientific World JournalVolume 2013 Article ID 641420 11 pageshttpdxdoiorg1011552013641420

Research ArticleMicelle-Assisted Synthesis of Al2O3sdotCaO NanocatalystOptical Properties and Their Applications in Photodegradationof 246-Trinitrophenol

Ayesha Imtiaz1 Muhammad Akhyar Farrukh1

Muhammad Khaleeq-ur-rahman1 and Rohana Adnan2

1 Department of Chemistry GC University Lahore 54000 Lahore Pakistan2 School of Chemical Sciences Universiti Sains Malaysia 11800 Pulau Pinang Malaysia

Correspondence should be addressed to Muhammad Akhyar Farrukh akhyar100gmailcom

Received 26 August 2013 Accepted 19 September 2013

Academic Editors O Gonzalez Diaz and J Yu

Copyright copy 2013 Ayesha Imtiaz et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Calcium oxide (CaO) nanoparticles are known to exhibit unique property due to their high adsorption capacity and good catalyticactivity In this work the CaO nanocatalysts were prepared by hydrothermal method using anionic surfactant sodium dodecylsulphate (SDS) as a templating agent The as-synthesized nanocatalysts were further used as substrate for the synthesis of aluminadoped calcium oxide (Al

2O3sdotCaO) nanocatalysts via deposition-precipitation method at the isoelectric point of CaO The

Al2O3sdotCaO nanocatalysts were characterized by FTIR XRD TGA TEM and FESEM techniques The catalytic efficiencies of

these nanocatalysts were studied for the photodegradation of 246-trinitrophenol (246-TNP) which is an industrial pollutantspectrophotometrically The effect of surfactant and temperature on size of nanocatalysts was also studied The smallest particlesize and highest percentage of degradation were observed at critical micelle concentration of the surfactantThe direct optical bandgap of the Al

2O3sdotCaO nanocatalyst was found as 33 eV

1 Introduction

Metal oxide nanoparticles play effective role in degradation ofhazardous chemicals Their highly intrinsic surface area andcatalytic properties have made them destructive adsorbentsThese metal oxides not only adsorb hazardous chemicals ontheir surface but also destroy them into smaller and lessharmful by-products [1 2] They can destroy a wide range ofsuch chemicals for example chlorobenzenes organosulfursorganophosphates and nitroaromatics These chemicals arepresent or used in synthesis of explosive materials insecti-cides pollutants and chemical warfare agents [3ndash15] Theirincreased consumption and improper disposal have becomeserious environmental risk Some of them are penetratinginto the ground water through soil causing serious environ-mental and health problems [16]

Nitrophenols (NPs) are primarily concerned toxic pollu-tants by the United States Environmental Protection Agency

(USEPA) [17] as these compounds have been found in indus-trial and agricultural wastes These are anthropogenic nox-ious inhibitory and biorefractory organic compounds andare considered as hazardous substances [18] Among these24-dinitrophenol (24-DNP) 25-dinitrophenol (25-DNP)26-trinitrophenol (26-DNP) and 246-TNP (246-TNP)are the most common and multipurpose industrial chem-icals with wide-ranging applications as insecticides dyesdrugs and ordnance compounds [19ndash25] Due to biorefrac-tory properties of these pollutants the biological techniquesappear futile or take protracted incubation time on thedegradation [26ndash28] Thus it is significantly important todevelop new remediation methods for the decomposition ofthese organic pollutants

Magnesium oxide nanoparticles were found as an effec-tive adsorbent for the 24-dinitrotoluene (24-DNT) and246-trinitrotoluene (246-TNT) [29] Photocatalytic degra-dation of nitrophenols and nitroamines was also observed on

2 The Scientific World Journal

titanium oxide [12 30 31] iron oxide [16] and gold loadedaluminium oxide [32] Activity of calcium oxide nanoparti-cles was studied against the degradation of dimethyl methyl-phosphonate (DMMP) and it was found that these nanoparti-cles have the ability to degrade other warfare chemical agents[5 33] Degradation of such compounds was also observedwhen aluminium oxide nanoparticles were used [3 6 9 32]

Surfactants play an important role in the preparation ofmetal oxide nanoparticles because of their influence on par-ticle growth coagulation and flocculation Under hydrother-mal condition smallest particle size was reported by usinganionic surfactant (SDS) as compared to cationic surfactant(CTABr) and nonionic surfactant (PEG) [34 35] Severalmethods like anodization [36] wet oxidation [37] sol-gel[38] hydrothermal treatment [34] deposition precipitation[22 32] and thermal vapor deposition [39]methods are beingapplied for the synthesis of nanoparticles

In the current study CaO and Al2O3sdotCaO nanocatalysts

were synthesized using hydrothermal method by varyingthe concentration of sodium dodecyl sulphate (SDS) ananionic surfactant The objective of this study is to assess thephotodegradation of selected ordnance compound by CaOand Al

2O3sdotCaO nanocatalysts The ordnance compound of

concern 246-TNP (246-trinitrophenol or picric acid) wasconsidered of priority for this study The effects of tempera-ture and surfactant were studied for the synthesis of nanocat-alysts and catalytic properties of nanocatalysts were assessedfor degradation of 246-TNP

2 Materials and Methods

21 Materials Calcium chloride anhydrous (CaCl2) sodium

hydroxide (NaOH) and sodium dodecyl sulfate (SDS)were purchased from Merck while aluminium chloride(AlCl3sdot6H2O) and methanol (CH

3OH) were from Riedel-de

Haen For the catalytic reaction 246-TNP was purchasedfrom Riedel-de Haen All chemicals were used as receivedwithout any further purification

22 Characterization The CaO nanocatalysts obtained weresubjected to thermogravimetric analysis (TGA) by usingSDT Q600 TGA Structural analysis of CaO and Al

2O3sdotCaO

nanocatalysts was done using Fourier Transform Infrared(FTIR)mdashMIDAC 2000 with KBr powder and powder X-raydiffractometer (XRD) using PANalytical MPD XrsquoPERT PROThe diffraction patterns were compared using the standarddatabase from International Centre for Diffraction Data(ICDD) The morphology and particle size of nanocatalystswas determined by FEI quanta 200 F Field Emission ScanningElectron Microscope (FESEM) and Philips CM12 80 kVTransmission Electron Microscope (TEM) HPLC analysiswas performed on Shimadzu model LC 20-AT instrumentequipped with diode array detector (SPD-M20A Shimadzu)Chromatographic separation was performed by using C-18column (250times46mm 5 120583mpacking) with isocratic solutionAn injection volume of 20 120583L was used for each sampleThe peaks were observed at wavelength of 355 nm GC-MS analyses were performed on Shimadzu model QP-2010instrument

Hydrothermal treatment

Deposition precipitation method

(SDS) Anionic surfactant + CaCl2

Ca(OH)2Δ600

∘C3h

Δ600∘C

Al2O3middot6H2O

Al2O3middotCaO

Figure 1 Experimental scheme for the synthesis of (a) CaO and (b)Al2O3sdotCaO nanocatalysts

23 Synthesis of CaO Nanocatalysts by Hydrothermal MethodCaO nanocatalysts were synthesized by changing the experi-mental parameters that is temperature and concentration ofsurfactant to study their effect on particle size and catalyticactivity Synthesis method of CaO is depicted in Figure 1(a)

The mixture containing 015M of CaCl2and 0008M

sodium dodecyl sulfate (SDS) was magnetically stirred atambient temperatureThe precursor to surfactant molar ratiowas taken as 1M 005M Sodium hydroxide (030M) solu-tionwas added dropwise and the reaction solutionwas stirredfor 30 minutes After stirring the reaction suspension wasplaced in a Teflon line autoclave (hydrothermal bomb) andkept in an oven for 4 h at the desired temperatures (250 180160 and 140∘C)

After 4 h the autoclave was removed from the ovenand allowed to cool for 2 h at ambient temperature Theprecipitates of Ca(OH)

2were separated and washed 3 times

with methanol and 2 times with deionized water to removeany reactant ions or surfactant and neutralize their pH byusing centrifugation machine at the speed of 13000 rpm Theprecipitates were dried and calcined at 600∘C in a furnacewith air flow for 3 h [40]

Similar process (Figure 1(a)) was adopted to study theeffect of surfactant on CaO nanocatalysts Only the molarconcentration of SDS (0004 0006 0008 001 and 0012M)was varied to be closemdashand far from its critical micelleconcentration (CMC) value which is 81mM [41]

24 Preparation of Alumina Supported CaO Nanocatalystsby Deposition Precipitation Method Synthesis of aluminadoped CaO nanocatalysts was carried out by deposition pre-cipitation method [32] AlCl

3sdot6H2O and CaO nanocatalysts

were used as precursors 15mM solution of AlCl3sdot6H2O

was prepared in 9mL deionised water and 50mg of CaO

The Scientific World Journal 3

nanocatalysts was added at different time intervals to attainpH 123 (isoelectric point) [42] Meanwhile the reactionwas constantly stirred on magnetic stirring plate Teflon lineautoclave was filled with reaction solution and kept in theoven for 4 h at the same temperature as that of CaO nanocat-alysts precursor Similarly the precipitates were washed andcalcined The experimental setup is displayed in Figure 1(b)

3 Results and Discussion

31 Thermogravimetric Analyses Figure 2 shows TGADSCprofile of the Ca(OH)

2synthesized with SDS at 180∘C for

4 h via hydrothermal treatment A significant weight loss(1625) is observed in the temperature range 375ndash450∘Cwhich can be attributed to the thermal decomposition ofCa(OH)

2 The observed weight loss in the range is smaller

than the theoretical value (243) calculated on the assump-tion of total dehydration of Ca(OH)

2to CaO [40]

The results indicate that a nearly complete conversion ofCa(OH)

2to CaO took place below 600∘C This implies that

the surfactant used in the fabrication of CaO nanocatalystshad been almost removed at around 450∘C

32 Fourier Transform Infrared Analyses FTIR peaks(Figure 3) at 3427 cmminus1 and 3453 cmminus1 can be attributed tothe stretching and bending vibrations of hydrogen-bondedsurface OH groups (physisorbed water) It reveals that only aslight amount of water molecules is retained in the fabricatedCaO and Al

2O3sdotCaO samples The appearance of strong IR

absorption band at 424 cmminus1 may be attributed to the latticevibrations of CaO [43]The IR absorption bands at 1415 cmminus1and 1439 cmminus1 are due to the symmetric stretching vibrationof unidentate carbonate Weak absorption band at 875 cmminus1further demonstrates the presence of carbonate species Thisis due to exposure of highly reactive surface area of CaO toair during calcination which resulted in the formation ofconsiderable amount of CO

2and H

2O which are adsorbed

on the surface of CaO in the form of free ndashOH and carbonatespecies This indicates that surface ndashOH and lattice oxygenof CaO do provide oxygen which is more assessable on highsurface area samples (Figure 3(a)) [44 45] In Figure 3(b)the peaks at 821 cmminus1 722 cmminus1 and 569 cmminus1 are due to thestretching vibration of AlndashO bond [46]

33 X-Ray Diffraction Analyses The XRD pattern (Figure 4)of the CaO obtained with SDS heated at 180∘C for 4 h afterhydrothermal treatment shows that the nanocatalysts can beindexed to cubic CaO Their lattice parameters agree wellwith the corresponding standard values given in JCPDSPDF 82-1690 (CaO) The intense peaks at 322∘ 373∘ 545∘645

∘ and 673∘ correspond to the (111) (200) (202) (311)and (222) crystal planes respectively The average crystallitesize (315 nm) was determined from the broadenings ofcorresponding peaks by using Scherrerrsquos equation

119863 =

119896120582

120573 (cos 120579) (1)

0 100 200 300 400 500

minus5

minus10

minus15

Temperature (∘C)

t flow

Figure 2 TGA (solid line)DSC (dotted line) plots of uncalcinedsample prepared with 0008M SDS at 180∘C for 4 h

873 821 72

3427777

4341343

555555

873 11

8211111 72

22222256

Wavenumber (cmminus1)3500 2500 1500 500

Figure 3 FTIR spectra for (a) CaO fabricated with surfactant (SDS)and (b) Al

2O3sdotCaO nanocatalysts

(311)(222)(111)

2120579 (deg)25 30 35 40 45 50 55 60 65

Figure 4 XRD pattern of CaO nanocatalyst fabricated with surfac-tant

11001000

900800700600500400300200100

(231)(400)

(351) (602)

(444)(362)

(454) (464)(472)(536)

(231((((( ))))(400)

((351) (602)

(444)(362)

(454) (464)(472( )(536)))

2120579 (deg)25 30 35 40 45 50 55

Figure 5 XRD pattern of Al2O3sdotCaO nanocatalyst

where 119863 is the mean crystallite size 119896 is the grain shapedependent constant 089 120582 is the wavelength of the incidentbeam in nm 120579 is the Bragg reflection angle and 120573 is the linebroadening at half the maximum intensity in radians

The 2120579 values of Al2O3sdotCaO nanocatalysts (Figure 5)

were compared with the ICDD database to identify thephase purity and composition formed Aluminium formsCa3Al2O6phase (PDF 00-006-0495)with the calciumoxide

nanoparticles at 600∘C due to strong AlndashO interaction [4748] The essential peaks at 2120579 = 209∘ 218∘ 233∘ 267∘332

∘ 348∘ 372∘ 408∘ 414∘ 448∘ 488∘ 496∘ and 499∘correspond to the lattice planes (302) (231) (400) (241)(440) (351) (602) (444) (362) (454) (464) (472) and(536) respectively The average crystallite size of 364 nm forCa3Al2O6was calculated by using (1) Uniform incorporation

and distribution of aluminium into the CaO matrix may beresponsible for the smaller crystallite size [49]

34 Optical Properties of Al2O3sdotCaO Nanocatalysts Optical

properties of Al2O3sdotCaO nanocatalysts were analyzed by

UV-Vis absorption measurement at room temperature andusing deionised water as blank The sample was preparedby dispersing 36mg of Al

2O3sdotCaO nanocatalysts in 10mL

of deionised water and stirring by magnetic stirrer for15min A homogeneous suspension solution was preparedand subjected for assessment for optical properties Figure 6describes typical absorption spectra of Al

2O3sdotCaO nanocat-

alysts which shows the shifting of absorption edges to theshorter wavelength (blue shift)

Equation (2) was used to calculate optical absorptioncoefficient 120572 from absorption data

120572 = 2303

3120588119860

119897119888119872

where 120588 is the theoretical density of Al2O3sdotCaO (303 g cmminus3)

119860 is the absorbance of Al2O3sdotCaO nanocatalyst solution 119897 is

the optical path length of quartz cell (1 cm) 119888 is the molar

0 200 400 600 800 1000 1200

Wavelength (nm)

Figure 6 UV-Vis spectra for Al2O3sdotCaO nanocatalyst

1 12 14 16 18 2h (eV)

ln120572

Figure 7 ln 120572 versus ℎ] for determination of the localized tail state119864

119890

concentration of suspension solution and119872 is themolecularweight of Al

Using Urbachrsquos equation (3) the density of the localizedtail state (119864

119890= 187 eV) in the forbidden energy gap was

determined by plotting ln120572 versus ℎ] as shown in Figure 7

120572 = 120572

0119890

ℎ]119864119890

Here 1205720a is constant and ℎ] is the energy of photons

The optical band gap for direct transition was determinedby plotting (120572ℎ])2 versus ℎ] using

120572ℎ] = 119861(ℎ] minus 119864119892)

119899

where 119861 is constant and nature of transition 119899 has beenassumed to have values 12 2 32 and 3 for direct indi-rect forbidden direct and forbidden indirect transitionsrespectively [50 51] The direct optical band gap energy 119864

119892is

determined by extrapolating the linear portion of the curve inFigure 8 the intersection of the extrapolation gives the valueof 33 eV which is much less than band gap energy of Al

(72 eV) [52]Proposed behavior of Al

2O3sdotCaO nanocatalyst towards

organic pollutant due to band gap energy is illustrated inFigure 9

01 2 3 4 5 6 7 8

h (eV)

(120572h)2

(cmminus1

1E + 10

8E + 09

6E + 09

4E + 09

2E + 09

Figure 8 Plot of (120572ℎ])2 versus ℎ] of Al2O3sdotCaO nanocatalysts

Organic pollutant

Intermediates

Organic pollutant

Intermediates

CO2 + H2O

Ca3Al2O6

OHminus

eminus∙Ominus

O2minus

Figure 9 Mechanism of action of Al2O3sdotCaO nanocatalyst

35 FESEM of CaO and Al2O3sdotCaO Nanocatalysts Fig-

ures 10(a) and 10(b) provide the representative FESEMimages of the CaO and Al

2O3sdotCaO nanocatalysts fabri-

cated with surfactant-assisted hydrothermal treatment at180

∘C for 4 h and calcination at 600∘C for 3 h It wasobserved in Figure 10(a) that the CaO samples containrounded coagulated nanocatalysts After doping of aluminaon CaO nanocatalysts agglomerated particles of sample wereobserved in Figure 10(b)

36 TEM of CaO and Al2O3sdotCaO Nanocatalysts Represen-

tative TEM image of the CaO and Al2O3sdotCaO nanocatalysts

obtained after hydrothermal treatment is shown in Figure 11The nanocatalysts exist in coagulated form with the particlesize of 16 nm (Figure 11(a)) The particles size is decreasedto 36 nm after the formation of Al

(Figure 11(b))

37 Catalytic Activity of CaO and Al2O3sdotCaO Nanocatalysts

A mixture of 5mg of CaO nanocatalysts and 25mL solutionof 246-TNP (15 ppm) was placed under UV irradiation

with constant stirring for 15 minutes at ambient temperatureOn the basis of Beer-Lambert law calibration was done for246-TNP at a wavelength of maximum absorptivity 120582max356 nm [53] The catalytic activity was determined using UVSpectrophotometer (UV-1700 Shimadzu) by measuring thechange in absorbance at 356 nm every 60-second intervalSameprocedurewas adopted to determine catalytic activity ofAl2O3sdotCaO nanocatalysts against 246-TNP [54] The analy-

sis of samples showed a continuous decrease in absorptionat 120582max = 356 nm which was used to track the degradationof 246-TNP [55] It is evident that reaction kinetics of bothCaO (Figure 12(a)) and Al

2O3sdotCaO (Figure 12(b)) nanocata-

lysts with 246-TNP follows first order The first order rateconstant values 1198961015840 were determined from the slope of thegraphs as shown in Figures 12(a) and 12(b)

38 Effect of Variation of Temperature on Catalytic Activity ofCaO Nanocatalysts Catalytic activity of CaO nanocatalystssynthesized by varying hydrothermal treatment tempera-ture (140 160 180 and 250∘C) was studied while keepingother experimental parameters constant It was observedthat an increase in temperature (from 140∘C to 180∘C)resulted in increases in rate constant 119896 value (00732 00791and 01283minminus1) but the catalytic activity decreases to01124minminus1 at 250∘C This change in the catalytic activitytrend suggests that high hydrothermal temperature favors fastreaction which increases the particle size and decreases thesurface area and contributes to destructive adsorbent ability

39 Effect of Variation of Surfactant Concentration on Cat-alytic Activity of CaO and Al

2O3sdotCaO Nanocatalysts The

synthesis of CaO nanocatalysts under basic conditions isbelieved to follow the XminusI+Sminusmodule where Sminus is the anionicsurfactant I+ is the inorganic precursor andXminus is the counterion [56] A generalized mechanism of electrostatic interac-tion between inorganic precursor surfactant and counterions was proposed in Figure 13 When sodium hydroxideis added to the system Na+ and OHminus ions are supposedto surround Ca2+ndashDSminus The electrostatic attraction betweenCa2+ and DSminus is stronger than that between Na and SDminusions this behavior enhances the particle formation [57]Na+ joins with Clminus to make NaCl in the mixture systemdue to the electrostatic repulsion of Clminus and DSminus The OHminusions self-assembled around the micelle so Ca2+ ions wereattracted towards OHminus to form Ca(OH)

2in the presence of

surfactant (templating agent) In the final step of the processthe template was removed by calcination at 600∘C for 3 h togenerate pores

The catalytic activity of CaO and Al2O3sdotCaO nanocata-

lysts (synthesized via hydrothermal treatment at 180∘C and4 h using different surfactant (SDS)) concentration is shownin Tables 1 and 2 It was observed that Al

2O3sdotCaO nanocat-

alysts are more effective catalyst for the degradation of246-TNP as compared to the CaO nanocatalysts Therate constant values 119896 of different samples of CaO andAl2O3sdotCaO nanocatalyst at the same parameters were com-

pared Al2O3sdotCaO nanocatalysts have higher rate constant

(01251minminus1) than CaO nanocatalyst (01233minminus1) at0004M concentration of SDS

(a) (b)

Figure 10 FESEM images for (a) CaO nanocatalysts fabricated with surfactant and (b) alumina supported CaO nanocatalysts

(a) (b)

Figure 11 TEM images of (a) CaO and (b) Al2O3sdotCaO nanocatalysts fabricated with surfactant (SDS)

12 14 16 18 20 22Time (min)

CaO (0008M) CMCCaO (0006M)CaO (001M)CaO (0004M)CaO (0012M)

minus05

minus1

minus15

minus2

minus25

minus3

ndashAinfin

010 12 14 16 18 20 22

Time (min)

minus05

minus1

minus15

minus2

minus25

minus3

minus35

minus4

minus45

ndashAinfin

Al2O3middotCaO (0008M) CMCAl2O3middotCaO (0006M)Al2O3middotCaO (0001M)Al2O3middotCaO (0004M)Al2O3middotCaO (0012M)

Figure 12 Plot of ln(119860ndash119860infin) versus time for the oxidation of 246-TNP with (a) CaO and (b) Al

2O3sdotCaO nanocatalysts prepared under

different concentrations of surfactant

Film of surfactant molecules on water

surface

Hydrophobic tail of surfactant (SDS) issequestered from

water to form micelle

Surfactant (SDS)

Hydrophilic headHydrophobic tail

Formation of OHminusCa2+DSminussystem after addition of

Ca2+ ions surroundingthe anionic head (DSminus)

of micelle afteraddition of CaCl2

Ominus

Ca2+OHminus

OHminus

ClminusClminus

Clminus

Figure 13 Mechanism of micelle assisted formation of OHminusCa2+DSminus system

It was observed that the highest 119896 values for both CaOand Al

2O3sdotCaO were found at CMC of SDS in accordance

to the small particle size of these nanocatalysts at thisconcentration The 119896 value increases (particle size decreases)when the nanocatalysts were prepared by using surfactantfrom 0004 to 0008M as the precursors are well dispersedin the surfactant template However further increase insurfactant concentration from 0008 to 0012M decreases the119896 values and increases the particle size due to formation ofmicelle which coagulates the particles A parabola is formedshowing the relationship between 119896 values and surfactantconcentration as shown in Figure 14

310 Degradation Mechanism of 246-TNP Degradation of246-TNP by nanocatalysts was observed by HPLC and GC-MS analysis A 15 ppm solution of picric acid (015mg) wasfreshly prepared in 100mL deionized water and used asstandard solutionMixtures of each (5mg) calcium oxide andAl2O3sdotCaO nanocatalysts were prepared in 25mL solution

of 246-TNP (15 ppm) and placed under UV irradiationwith constant stirring for 15 minutes at ambient temperatureThe sample solutions were filtered and then degassed bysonication before use

Mobile phase was prepared for HPLC analyses by mixing70 methanol with 01M acetic acid buffer in the ratio of97 3 vv The mobile phase was filtered and then degassedby sonication before use [58] The data was analyzed byobtaining area under sample peaks at 355 nm The observedretention time for standard 246-TNP solution was found7425min as shown in Figure 15

Each sample solutionwas injected separately in theHPLCand none of them showed any peak at the wavelength of

Table 1 Effect of surfactant concentration on catalytic activity ofCaO nanocatalysts prepared at 180∘C hydrothermal condition

As-synthesized sample Surfactant conc (M) ldquo119896rdquo value (minminus1)CaO 0004 01233CaO 0006 01243CaO 0008 01283CaO 001 00931CaO 0012 00907

Table 2 Effect of surfactant concentration on catalytic activity ofAl2O3sdotCaO nanocatalysts prepared at 180∘C under hydrothermalcondition

As-synthesized sample Surfactant conc (M) ldquo119896rdquo value (minminus1)Al2O3sdotCaO 0004 01251Al2O3sdotCaO 0006 01305Al2O3sdotCaO 0008 01577Al2O3sdotCaO 001 00897Al2O3sdotCaO 0012 00824

355 nm These results lead to the conclusion that the picricacid was completely degraded by CaO and Al

2O3sdotCaO

nanocatalysts (Figure 16)GC-MS technique was used to determine the inter-

mediates generated during catalytic degradation of 246-TNP Sample was prepared by suspending 5mg Al

2O3sdotCaO

nanocatalysts in 25mL solution of 246-TNP (15 ppm)Thenit was placed under UV irradiation with constant stirring for

0 0002 0004 0006 0008 001 0012 0014Surfactant (M)

ldquokrdquo v

(minminus1)

Al2O3middotCaO

Figure 14 Plot of surfactant concentration versus rate constant ldquo119896rdquoof the degradation of 246-TNP

00 75 100 125 150

Time (min)

Figure 15 HPLC chromatograph for 246-TNP

15 minutes at ambient temperature The sample solution wasfiltered before use

A schematic diagram is proposed as given in Scheme 1 onthe basis of GC-MS chromatogram (Figure 17)

4 Conclusion

CaO and Al2O3sdotCaO nanocatalysts were prepared by vary-

ing the temperature and surfactant (SDS) concentrationabove and below CMC value using hydrothermal and usingdeposition precipitation method Catalytic activity of thesenanocatalysts was measured against the degradation of 246-TNP which proved that the nanocatalysts are effective cat-alysts The highest rate constant value 119896 was observed inthose samples which were prepared at CMC value of the

minus500

minus1000

minus1500

minus2000

minus2500

minus1000

minus2000

minus3000

minus4000

00 25 50 75 100

Time (min)

Figure 16 HPLC chromatograph showing the degradation of 246-TNP

67 77 94 108 150121 134 192 206

R time 1625Base peak 440

24022020018016014012010080604020mz

43 60 73

115129

157 171213

24022020018016014012010080604020mz

55 67 8195

110149

123137 192 209Inte

24022020018016014012010080604020mz

Figure 17 GC-MS chromatograms for degradation of 246-TNPby Al

2O3sdotCaO nanocatalyst at retention time (a) 165min (b)

9805min and (c) 10405min

anionic surfactant Compared to CaO nanocatalysts theAl2O3sdotCaO nanocatalysts have the highest catalytic activity

(01577minminus1) The band gap of the Al2O3sdotCaO nanocatalyst

was calculated as 33 eV

O246-Trinitrophenol

26-Dinitrophenol

O24-Dinitrophenol

4-Nitrobenzene-123-triol

24-dienoate

dioic acid

2-Oxopentanoate

2-Nitrophenol

Cyclohexa-35-diene-12-dione

Benzene-12-diol

O4-Nitrophenol

OCyclohexa-25-diene-14-dione

Benzene-14-diol

Furan-25-dione

23-Dihydroxybutanedioic acid

3-Oxopropanoate

Acetaldehyde

Ring cleavage

Ominus

N+Ominus

Ominus

OminusOminus

Ominus

mz = 139

mz = 108

mz = 110

mz = 157

mz = 150

2-enoic acidmz = 115mz = 115

mz = 115

Ethenonemz = 42 Acetic acid

mz = 60

H3CH3C

Hminus

minus2H Propanoatemz = 73

2-Oxopropanoatemz = 87

mz = 98

mz = 87mz = 44

H2O + CO2

mz = 44

minusNH2

minusCO2

mz = 157

mz = 171

mz = 184

mz = 139

mz = 184

mz = 108

mz = 110

(2Z4E)-5-Nitro-2-oxidopenta-

(2E4E)-2-Aminohexa-24-diene

(2Z)-3-Oxidohex-2-enedioate

(2Z)-3-Amino-4-oxobut-(2Z)-3-Carboxyprop-2-enoate(2E)-3-Carboxyprop-2-enoate

Scheme 1 Mechanism for degradation of 246-TNP by Al2O3sdotCaO nanocatalyst

Acknowledgments

XRD facilities provided by the Physics Department of GCUniversity Lahore are gratefully acknowledged The authorsare grateful to The World Academy of Sciences (TWAS) forfinancial support to purchase scientific equipments to carryout this project and Universiti Sains Malaysia is acknowl-edged to provide characterization of samples by TEMthrough Research University (RU) Grant no 1001PKIMIA815099

References

[1] M A Henderson T Jin and J M White ldquoThe desorption anddecomposition of trinitrotoluene adsorbed onmetal oxide pow-dersrdquo Applied Surface Science vol 27 no 1 pp 127ndash140 1986

[2] K J Klabunde and R Richards Nanoscale Materials in Chem-istry John Wiley amp Sons 2009

[3] T Z Tzou and S W Weller ldquoCatalytic oxidation of dimethylmethylphosphonaterdquo Journal of Catalysis vol 146 no 2 pp370ndash374 1994

[4] G W Wagner P W Bartram O Koper and K J KlabundeldquoReactions of VX GD and HD with nanosize MgOrdquoThe Jour-nal of Physical Chemistry B vol 103 no 16 pp 3225ndash3228 1999

[5] G W Wagner O B Koper E Lucas S Decker and K JKlabunde ldquoReactions of VX GD and HD with nanosize CaOautocatalytic dehydrohalogenation of HDrdquoThe Journal of Phys-ical Chemistry B vol 104 no 21 pp 5118ndash5123 2000

[6] G W Wagner L R Procell R J OrsquoConnor et al ldquoReactionsof VX GB GD and HD with nanosize AL

2O3 Formation

of aluminophosphonatesrdquo Journal of the American ChemicalSociety vol 123 no 8 pp 1636ndash1644 2001

[7] S M Kanan Z Lu and C P Tripp ldquoA comparative study of theadsorption of chloro- and non-chloro-containing organophos-phorus compounds onWO

3rdquoThe Journal of Physical Chemistry

B vol 106 no 37 pp 9576ndash9580 2002[8] X Ma M Zheng W Liu Y Qian B Zhang and W Liu

ldquoDechlorination of hexachlorobenzene using ultrafine CandashFecomposite oxidesrdquo Journal of Hazardous Materials vol 127 no1ndash3 pp 156ndash162 2005

[9] J C Chen and C T Tang ldquoPreparation and application ofgranular ZnOAl

2O3catalyst for the removal of hazardous tri-

chloroethylenerdquo Journal of Hazardous Materials vol 142 no 1-2 pp 88ndash96 2007

[10] W O Gordon B M Tissue and J R Morris ldquoAdsorption anddecomposition of dimethyl methylphosphonate on Y

2O3nano-

particlesrdquoThe Journal of Physical Chemistry C vol 111 no 8 pp3233ndash3240 2007

[11] O B Koper S Rajagopalan S Winecki and K J KlabundeldquoNanoparticle metal oxides for chlorocarbon and organophos-phonate remediationrdquo in Environmental Applications of Nano-materials Synthesis Sorbents and Sensors pp 3ndash24 2007

[12] D Cropek P A Kemme O V Makarova L X Chen and TRajh ldquoSelective photocatalytic decomposition of nitrobenzeneusing surfacemodifiedTiO

2nanoparticlesrdquoThe Journal of Phys-

ical Chemistry C vol 112 no 22 pp 8311ndash8318 2008[13] G W Wagner Q Chen and Y Wu ldquoReactions of VX GD and

HDwith nanotubular titaniardquoThe Journal of Physical ChemistryC vol 112 no 31 pp 11901ndash11906 2008

[14] A Saxena H Mangal P K Rai A S Rawat V Kumar and MDatta ldquoAdsorption of diethylchlorophosphate on metal oxide

nanoparticles under static conditionsrdquo Journal of HazardousMaterials vol 180 no 1ndash3 pp 566ndash576 2010

[15] L A Patil A R Bari M D Shinde V Deo and M P KaushikldquoDetection of dimethyl methyl phosphonatemdasha simulant ofsarin the highly toxic chemical warfaremdashusing platinum acti-vated nanocrystalline ZnO thick filmsrdquo Sensors and ActuatorsB vol 161 no 1 pp 372ndash380 2012

[16] A Halasz C Groom E Zhou et al ldquoDetection of explosivesand their degradation products in soil environmentsrdquo Journalof Chromatography A vol 963 no 1-2 pp 411ndash418 2002

[17] USEPA Health and Environmental Effects Profile for Nitrophe-nols Environmental Protection Agency Environmental Crite-ria and Assessment Office Cincinnati Ohio USA 1985

[18] R Belloli E Bolzacchini L Clerici B Rindone G Sesana andV Librando ldquoNitrophenols in air and rainwaterrdquo EnvironmentalEngineering Science vol 23 no 2 pp 405ndash415 2006

[19] M Shimazu A Mulchandani and W Chen ldquoSimultane-ous degradation of organophosphorus pesticides and p-nitro-phenol by a genetically engineered Moraxella sp with surface-expressed organophosphorus hydrolaserdquo Biotechnology andBioengineering vol 76 no 4 pp 318ndash324 2001

[20] J B Lippincot List of Worldwide Hazardous Chemical andPollutants The Forum for Scientific Excellence New York NYUSA 1990

[21] M S Dieckmann and K A Gray ldquoA comparison of the degra-dation of 4-nitrophenol via direct and sensitized photocatalysisin TiO

2slurriesrdquo Water Research vol 30 no 5 pp 1169ndash1183

1996[22] S Ali M A Farrukh andM Khaleeq-ur-Rahman ldquoPhotodeg-

radation of 246-trinitrophenol catalyzed byZnMgOnanopar-ticles prepared under aqueous-organic mediumrdquo Korean Jour-nal of Chemical Engineering vol 30 no 11 2013

[23] A Gutes F Cespedes S Alegret andM del Valle ldquoDetermina-tion of phenolic compounds by a polyphenol oxidase ampero-metric biosensor and artificial neural network analysisrdquo Biosen-sors and Bioelectronics vol 20 no 8 pp 1668ndash1673 2005

[24] K Tanaka K Padermpole and T Hisanaga ldquoPhotocatalyticdegradation of commercial azo dyesrdquo Water Research vol 34no 1 pp 327ndash333 2000

[25] K W Hofmann H-J Knackmuss and G Heiss ldquoNitrite elim-ination and hydrolytic ring cleavage in 246-trinitrophenol(picric acid) degradationrdquo Applied and Environmental Microbi-ology vol 70 no 5 pp 2854ndash2860 2004

[26] Z Aleksieva D Ivanova T Godjevargova and B AtanasovldquoDegradation of some phenol derivatives by Trichosporon cuta-neum R57rdquo Process Biochemistry vol 37 no 11 pp 1215ndash12192002

[27] S Yi W-Q Zhuang B Wu S T-L Tay and J-H Tay ldquoBiodeg-radation of p-nitrophenol by aerobic granules in a sequencingbatch reactorrdquo Environmental Science and Technology vol 40no 7 pp 2396ndash2401 2006

[28] MC TomeiMCAnnesini R Luberti G Cento andA SenialdquoKinetics of 4-nitrophenol biodegradation in a sequencingbatch reactorrdquo Water Research vol 37 no 16 pp 3803ndash38142003

[29] V M Boddu D S Viswanath and S W Maloney ldquoSynthesisand characterization of coralline magnesium oxide nanoparti-clesrdquo Journal of the American Ceramic Society vol 91 no 5 pp1718ndash1720 2008

[30] Y Liu H Liu J Ma and X Wang ldquoComparison of degra-dation mechanism of electrochemical oxidation of di- and

tri-nitrophenols on Bi-doped lead dioxide electrodeeffect ofthe molecular structurerdquo Applied Catalysis B vol 91 no 1-2 pp284ndash299 2009

[31] O V Makarova T Rajh M C Thurnauer A Martin P AKemme and D Cropek ldquoSurface modification of TiO

2nano-

particles for photochemical reduction of nitrobenzenerdquo Envi-ronmental Science and Technology vol 34 no 22 pp 4797ndash4803 2000

[32] H Yazid R Adnan and M A Farrukh ldquoGold nanoparticlessupported on titania for the reduction of p-nitrophenolrdquo IndianJournal of Chemistry A vol 52 no 2 pp 184ndash191 2013

[33] Y Paukku A Michalkova and J Leszczynski ldquoAdsorption ofdimethyl methylphosphonate and trimethyl phosphate on cal-cium oxide an ab initio studyrdquo Structural Chemistry vol 19 no2 pp 307ndash320 2008

[34] M A Farrukh P Tan and R Adnan ldquoInfluence of reactionparameters on the synthesis of surfactant-assisted tin oxidenanoparticlesrdquo Turkish Journal of Chemistry vol 36 no 2 pp303ndash314 2012

[35] S Gnanam and V Rajendran ldquoAnionic cationic and non-ionic surfactants-assisted hydrothermal synthesis of tin oxidenanoparticles and their photoluminescence propertyrdquo DigestJournal ofNanomaterials andBiostructures vol 5 no 3 pp 623ndash628 2010

[36] H-S Goh R Adnan and M A Farrukh ldquoZnO nanoflakearrays prepared via anodization and their performance in thephotodegradation of methyl orangerdquo Turkish Journal of Chem-istry vol 35 no 3 pp 375ndash391 2011

[37] K M A Saron M R Hashim and M A Farrukh ldquoStress con-trol in ZnO films on GaNAl

2O3via wet oxidation of Zn under

various temperaturesrdquo Applied Surface Science vol 258 no 13pp 5200ndash5205 2012

[38] R Adnan N A Razana I A Rahman and M A FarrukhldquoSynthesis and characterization of high surface area tin oxidenanoparticles via the sol-gel method as a catalyst for the hydro-genation of styrenerdquo Journal of the Chinese Chemical Society vol57 no 2 pp 222ndash229 2010

[39] K M A Saron M R Hashim and M A Farrukh ldquoGrowth ofGaN films on silicon (111) by thermal vapor deposition methodoptical functions and MSM UV photodetector applicationsrdquoSuperlattices and Microstructures vol 64 pp 88ndash97 2013

[40] C Liu L Zhang J DengQMuHDai andHHe ldquoSurfactant-aided hydrothermal synthesis and carbon dioxide adsorptionbehavior of three-dimensionally mesoporous calcium oxidesingle-crystallites with tri- tetra- and hexagonal morpholo-giesrdquo The Journal of Physical Chemistry C vol 112 no 49 pp19248ndash19256 2008

[41] H B de Aguiar M L Strader A G F de Beer and S RokeldquoSurface structure of sodium dodecyl sulfate surfactant and oilat the oil-in-water droplet liquidliquid interface a manifesta-tion of a nonequilibrium surface staterdquo The Journal of PhysicalChemistry B vol 115 no 12 pp 2970ndash2978 2011

[42] D A Sverjensky ldquoZero-point-of-charge prediction from crystalchemistry and solvation theoryrdquo Geochimica et CosmochimicaActa vol 58 no 14 pp 3123ndash3129 1994

[43] M I Zaki H Knozinger B Tesche and G A H MekhemerldquoInfluence of phosphonation and phosphation on surface acid-base and morphological properties of CaO as investigated byin situ FTIR spectroscopy and electron microscopyrdquo Journal ofColloid and Interface Science vol 303 no 1 pp 9ndash17 2006

[44] O B Koper I Lagadic A Volodin and K J Klabunde ldquoAlka-line-earth oxide nanoparticles obtained by aerogel methods

Characterization and rational for unexpectedly high surfacechemical reactivitiesrdquo Chemistry of Materials vol 9 no 11 pp2468ndash2480 1997

[45] Y X Li H Li and K J Klabunde ldquoDestructive adsorption ofchlorinated benzenes on ultrafine (Nanoscale) particles of mag-nesium oxide and calcium oxiderdquo Environmental Science andTechnology vol 28 no 7 pp 1248ndash1253 1994

[46] J Hemalatha T Prabhakaran and R P Nalini ldquoA comparativestudy on particle-fluid interactions in micro and nanofluids ofaluminium oxiderdquoMicrofluidics and Nanofluidics vol 10 no 2pp 263ndash270 2011

[47] B Viswanath and N Ravishankar ldquoInterfacial reactions inhydroxyapatitealumina nanocompositesrdquo Scripta Materialiavol 55 no 10 pp 863ndash866 2006

[48] J Yu Q GeW Fang andH Xu ldquoInfluences of calcination tem-perature on the efficiency ofCaOpromotion overCaOmodifiedPt120574-Al

2O3catalystrdquo Applied Catalysis A vol 395 no 1-2 pp

114ndash119 2011[49] R Koirala G K Reddy and P G Smirniotis ldquoSingle nozzle

flame-made highly durable metal doped Ca-based sorbents forCO2capture at high temperaturerdquo Energy amp Fuels vol 26 no

5 pp 3103ndash3109 2012[50] A Gaber A Y Abdel-Latief M A Abdel-Rahim and M N

Abdel-Salam ldquoThermally induced structural changes and opti-cal properties of tin dioxide nanoparticles synthesized by aconventional precipitation methodrdquo Materials Science in Semi-conductor Processing vol 16 no 6 pp 1784ndash1790 2013

[51] E Filippo DManno A R de Bartolomeo andA Serra ldquoSinglestep synthesis of SnO

2ndashSiO2core-shell microcablesrdquo Journal of

Crystal Growth vol 330 no 1 pp 22ndash29 2011[52] S J Mousavi M R Abolhassani S M Hosseini and S A Sebt

ldquoComparison of electronic and optical properties of the andphases of alumina using density functional theoryrdquo ChineseJournal of Physics vol 47 no 6 pp 862ndash873 2009

[53] V Pimienta R Etchenique and T Buhse ldquoOn the origin of elec-trochemical oscillations in the picric acidCTAB two-phasesystemrdquo The Journal of Physical Chemistry A vol 105 no 44pp 10037ndash10044 2001

[54] M Ksibi A Zemzemi and R Boukchina ldquoPhotocatalyticdegradability of substituted phenols over UV irradiated TiO

2rdquo

Journal of Photochemistry and Photobiology A vol 159 no 1 pp61ndash70 2003

[55] J Li HQiao Y Du et al ldquoElectrospinning synthesis and photo-catalytic activity of mesoporous TiO

2nanofibersrdquoThe Scientific

World Journal vol 2012 Article ID 154939 7 pages 2012[56] M A Farrukh B-T Heng and R Adnan ldquoSurfactant-

controlled aqueous synthesis of SnO2nanoparticles via the

hydrothermal and conventional heatingmethodsrdquoTurkish Jour-nal of Chemistry vol 34 no 4 pp 537ndash550 2010

[57] H Iyota and R Krastev ldquoMiscibility of sodium chloride andsodiumdodecyl sulfate in the adsorbed filmand aggregaterdquoCol-loid and Polymer Science vol 287 no 4 pp 425ndash433 2009

[58] NIOSHManual of Analytical Methods vol 4 method no S228US Department of Health and Human Services Public HealthServices 2nd edition 1978

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Polymer ScienceInternational Journal of

ISRN Corrosion

CompositesJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

International Journal of

BiomaterialsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Ceramics

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2013

MaterialsJournal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

ISRN Materials Science

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

ISRN Nanotechnology

NanoparticlesJournal of

Smart Materials Research

MetallurgyJournal of

BioMed Research International

ISRN Polymer Science

Journal ofNanomaterials

titanium oxide [12 30 31] iron oxide [16] and gold loadedaluminium oxide [32] Activity of calcium oxide nanoparti-cles was studied against the degradation of dimethyl methyl-phosphonate (DMMP) and it was found that these nanoparti-cles have the ability to degrade other warfare chemical agents[5 33] Degradation of such compounds was also observedwhen aluminium oxide nanoparticles were used [3 6 9 32]

Surfactants play an important role in the preparation ofmetal oxide nanoparticles because of their influence on par-ticle growth coagulation and flocculation Under hydrother-mal condition smallest particle size was reported by usinganionic surfactant (SDS) as compared to cationic surfactant(CTABr) and nonionic surfactant (PEG) [34 35] Severalmethods like anodization [36] wet oxidation [37] sol-gel[38] hydrothermal treatment [34] deposition precipitation[22 32] and thermal vapor deposition [39]methods are beingapplied for the synthesis of nanoparticles

In the current study CaO and Al2O3sdotCaO nanocatalysts

were synthesized using hydrothermal method by varyingthe concentration of sodium dodecyl sulphate (SDS) ananionic surfactant The objective of this study is to assess thephotodegradation of selected ordnance compound by CaOand Al

2O3sdotCaO nanocatalysts The ordnance compound of

concern 246-TNP (246-trinitrophenol or picric acid) wasconsidered of priority for this study The effects of tempera-ture and surfactant were studied for the synthesis of nanocat-alysts and catalytic properties of nanocatalysts were assessedfor degradation of 246-TNP

2 Materials and Methods

21 Materials Calcium chloride anhydrous (CaCl2) sodium

hydroxide (NaOH) and sodium dodecyl sulfate (SDS)were purchased from Merck while aluminium chloride(AlCl3sdot6H2O) and methanol (CH

3OH) were from Riedel-de

Haen For the catalytic reaction 246-TNP was purchasedfrom Riedel-de Haen All chemicals were used as receivedwithout any further purification

22 Characterization The CaO nanocatalysts obtained weresubjected to thermogravimetric analysis (TGA) by usingSDT Q600 TGA Structural analysis of CaO and Al

2O3sdotCaO

nanocatalysts was done using Fourier Transform Infrared(FTIR)mdashMIDAC 2000 with KBr powder and powder X-raydiffractometer (XRD) using PANalytical MPD XrsquoPERT PROThe diffraction patterns were compared using the standarddatabase from International Centre for Diffraction Data(ICDD) The morphology and particle size of nanocatalystswas determined by FEI quanta 200 F Field Emission ScanningElectron Microscope (FESEM) and Philips CM12 80 kVTransmission Electron Microscope (TEM) HPLC analysiswas performed on Shimadzu model LC 20-AT instrumentequipped with diode array detector (SPD-M20A Shimadzu)Chromatographic separation was performed by using C-18column (250times46mm 5 120583mpacking) with isocratic solutionAn injection volume of 20 120583L was used for each sampleThe peaks were observed at wavelength of 355 nm GC-MS analyses were performed on Shimadzu model QP-2010instrument

Hydrothermal treatment

Deposition precipitation method

(SDS) Anionic surfactant + CaCl2

Ca(OH)2Δ600

∘C3h

Δ600∘C

Al2O3middot6H2O

Al2O3middotCaO

Figure 1 Experimental scheme for the synthesis of (a) CaO and (b)Al2O3sdotCaO nanocatalysts

23 Synthesis of CaO Nanocatalysts by Hydrothermal MethodCaO nanocatalysts were synthesized by changing the experi-mental parameters that is temperature and concentration ofsurfactant to study their effect on particle size and catalyticactivity Synthesis method of CaO is depicted in Figure 1(a)

The mixture containing 015M of CaCl2and 0008M

sodium dodecyl sulfate (SDS) was magnetically stirred atambient temperatureThe precursor to surfactant molar ratiowas taken as 1M 005M Sodium hydroxide (030M) solu-tionwas added dropwise and the reaction solutionwas stirredfor 30 minutes After stirring the reaction suspension wasplaced in a Teflon line autoclave (hydrothermal bomb) andkept in an oven for 4 h at the desired temperatures (250 180160 and 140∘C)

After 4 h the autoclave was removed from the ovenand allowed to cool for 2 h at ambient temperature Theprecipitates of Ca(OH)

2were separated and washed 3 times

with methanol and 2 times with deionized water to removeany reactant ions or surfactant and neutralize their pH byusing centrifugation machine at the speed of 13000 rpm Theprecipitates were dried and calcined at 600∘C in a furnacewith air flow for 3 h [40]

Similar process (Figure 1(a)) was adopted to study theeffect of surfactant on CaO nanocatalysts Only the molarconcentration of SDS (0004 0006 0008 001 and 0012M)was varied to be closemdashand far from its critical micelleconcentration (CMC) value which is 81mM [41]

24 Preparation of Alumina Supported CaO Nanocatalystsby Deposition Precipitation Method Synthesis of aluminadoped CaO nanocatalysts was carried out by deposition pre-cipitation method [32] AlCl

3sdot6H2O and CaO nanocatalysts

were used as precursors 15mM solution of AlCl3sdot6H2O

was prepared in 9mL deionised water and 50mg of CaO

2to CaO [40]

2and H

119863 =

119896120582

120573 (cos 120579) (1)

0 100 200 300 400 500

minus5

minus10

minus15

Temperature (∘C)

t flow

873 821 72

3427777

4341343

555555

873 11

8211111 72

22222256

(311)(222)(111)

2120579 (deg)25 30 35 40 45 50 55 60 65

11001000

900800700600500400300200100

(231)(400)

(351) (602)

(444)(362)

(454) (464)(472)(536)

(231((((( ))))(400)

((351) (602)

(444)(362)

(454) (464)(472( )(536)))

2120579 (deg)25 30 35 40 45 50 55

2O3sdotCaO nanocat-

120572 = 2303

3120588119860

119897119888119872

0 200 400 600 800 1000 1200

Wavelength (nm)

1 12 14 16 18 2h (eV)

ln120572

119890

120572 = 120572

0119890

ℎ]119864119890

120572ℎ] = 119861(ℎ] minus 119864119892)

119899

119892is

01 2 3 4 5 6 7 8

h (eV)

(120572h)2

(cmminus1

1E + 10

8E + 09

6E + 09

4E + 09

2E + 09

Organic pollutant

Intermediates

Organic pollutant

Intermediates

CO2 + H2O

Ca3Al2O6

OHminus

eminus∙Ominus

O2minus

(Figure 11(b))

2in the presence of

2O3sdotCaO nanocat-

(a) (b)

12 14 16 18 20 22Time (min)

minus05

minus1

minus15

minus2

minus25

minus3

ndashAinfin

010 12 14 16 18 20 22

Time (min)

minus05

minus1

minus15

minus2

minus25

minus3

minus35

minus4

minus45

ndashAinfin

surface

Surfactant (SDS)

Ominus

Ca2+OHminus

OHminus

ClminusClminus

Clminus

2O3sdotCaO

0 0002 0004 0006 0008 001 0012 0014Surfactant (M)

ldquokrdquo v

(minminus1)

Al2O3middotCaO

00 75 100 125 150

Time (min)

4 Conclusion

minus500

minus1000

minus1500

minus2000

minus2500

minus1000

minus2000

minus3000

minus4000

00 25 50 75 100

Time (min)

67 77 94 108 150121 134 192 206

24022020018016014012010080604020mz

43 60 73

115129

157 171213

24022020018016014012010080604020mz

55 67 8195

110149

123137 192 209Inte

24022020018016014012010080604020mz

O246-Trinitrophenol

26-Dinitrophenol

O24-Dinitrophenol

24-dienoate

dioic acid

2-Oxopentanoate

2-Nitrophenol

Benzene-12-diol

O4-Nitrophenol

Benzene-14-diol

Furan-25-dione

3-Oxopropanoate

Acetaldehyde

Ring cleavage

Ominus

N+Ominus

Ominus

OminusOminus

Ominus

mz = 139

mz = 108

mz = 110

mz = 157

mz = 150

mz = 115

mz = 60

H3CH3C

Hminus

mz = 98

mz = 87mz = 44

H2O + CO2

mz = 44

minusNH2

minusCO2

mz = 157

mz = 171

mz = 184

mz = 139

mz = 184

mz = 108

mz = 110

Acknowledgments

References

2O3 Formation

2O3nano-

2nano-

2rdquo

ISRN Corrosion

Advances in

ISRN Ceramics

Volume 2013

MaterialsJournal of

Journal of

ISRN Nanotechnology

2to CaO [40]

2and H

119863 =

119896120582

120573 (cos 120579) (1)

0 100 200 300 400 500

minus5

minus10

minus15

Temperature (∘C)

t flow

873 821 72

3427777

4341343

555555

873 11

8211111 72

22222256

(311)(222)(111)

2120579 (deg)25 30 35 40 45 50 55 60 65

11001000

900800700600500400300200100

(231)(400)

(351) (602)

(444)(362)

(454) (464)(472)(536)

(231((((( ))))(400)

((351) (602)

(444)(362)

(454) (464)(472( )(536)))

2120579 (deg)25 30 35 40 45 50 55

2O3sdotCaO nanocat-

120572 = 2303

3120588119860

119897119888119872

0 200 400 600 800 1000 1200

Wavelength (nm)

1 12 14 16 18 2h (eV)

ln120572

119890

120572 = 120572

0119890

ℎ]119864119890

120572ℎ] = 119861(ℎ] minus 119864119892)

119899

119892is

01 2 3 4 5 6 7 8

h (eV)

(120572h)2

(cmminus1

1E + 10

8E + 09

6E + 09

4E + 09

2E + 09

Organic pollutant

Intermediates

Organic pollutant

Intermediates

CO2 + H2O

Ca3Al2O6

OHminus

eminus∙Ominus

O2minus

(Figure 11(b))

2in the presence of

2O3sdotCaO nanocat-

(a) (b)

12 14 16 18 20 22Time (min)

minus05

minus1

minus15

minus2

minus25

minus3

ndashAinfin

010 12 14 16 18 20 22

Time (min)

minus05

minus1

minus15

minus2

minus25

minus3

minus35

minus4

minus45

ndashAinfin

surface

Surfactant (SDS)

Ominus

Ca2+OHminus

OHminus

ClminusClminus

Clminus

2O3sdotCaO

0 0002 0004 0006 0008 001 0012 0014Surfactant (M)

ldquokrdquo v

(minminus1)

Al2O3middotCaO

00 75 100 125 150

Time (min)

4 Conclusion

minus500

minus1000

minus1500

minus2000

minus2500

minus1000

minus2000

minus3000

minus4000

00 25 50 75 100

Time (min)

67 77 94 108 150121 134 192 206

24022020018016014012010080604020mz

43 60 73

115129

157 171213

24022020018016014012010080604020mz

55 67 8195

110149

123137 192 209Inte

24022020018016014012010080604020mz

O246-Trinitrophenol

26-Dinitrophenol

O24-Dinitrophenol

24-dienoate

dioic acid

2-Oxopentanoate

2-Nitrophenol

Benzene-12-diol

O4-Nitrophenol

Benzene-14-diol

Furan-25-dione

3-Oxopropanoate

Acetaldehyde

Ring cleavage

Ominus

N+Ominus

Ominus

OminusOminus

Ominus

mz = 139

mz = 108

mz = 110

mz = 157

mz = 150

mz = 115

mz = 60

H3CH3C

Hminus

mz = 98

mz = 87mz = 44

H2O + CO2

mz = 44

minusNH2

minusCO2

mz = 157

mz = 171

mz = 184

mz = 139

mz = 184

mz = 108

mz = 110

Acknowledgments

References

2O3 Formation

2O3nano-

2nano-

2rdquo

ISRN Corrosion

Advances in

ISRN Ceramics

Volume 2013

MaterialsJournal of

Journal of

ISRN Nanotechnology

11001000

900800700600500400300200100

(231)(400)

(351) (602)

(444)(362)

(454) (464)(472)(536)

(231((((( ))))(400)

((351) (602)

(444)(362)

(454) (464)(472( )(536)))

2120579 (deg)25 30 35 40 45 50 55

2O3sdotCaO nanocat-

120572 = 2303

3120588119860

119897119888119872

0 200 400 600 800 1000 1200

Wavelength (nm)

1 12 14 16 18 2h (eV)

ln120572

119890

120572 = 120572

0119890

ℎ]119864119890

120572ℎ] = 119861(ℎ] minus 119864119892)

119899

119892is

01 2 3 4 5 6 7 8

h (eV)

(120572h)2

(cmminus1

1E + 10

8E + 09

6E + 09

4E + 09

2E + 09

Organic pollutant

Intermediates

Organic pollutant

Intermediates

CO2 + H2O

Ca3Al2O6

OHminus

eminus∙Ominus

O2minus

(Figure 11(b))

2in the presence of

2O3sdotCaO nanocat-

(a) (b)

12 14 16 18 20 22Time (min)

minus05

minus1

minus15

minus2

minus25

minus3

ndashAinfin

010 12 14 16 18 20 22

Time (min)

minus05

minus1

minus15

minus2

minus25

minus3

minus35

minus4

minus45

ndashAinfin

surface

Surfactant (SDS)

Ominus

Ca2+OHminus

OHminus

ClminusClminus

Clminus

2O3sdotCaO

0 0002 0004 0006 0008 001 0012 0014Surfactant (M)

ldquokrdquo v

(minminus1)

Al2O3middotCaO

00 75 100 125 150

Time (min)

4 Conclusion

minus500

minus1000

minus1500

minus2000

minus2500

minus1000

minus2000

minus3000

minus4000

00 25 50 75 100

Time (min)

67 77 94 108 150121 134 192 206

24022020018016014012010080604020mz

43 60 73

115129

157 171213

24022020018016014012010080604020mz

55 67 8195

110149

123137 192 209Inte

24022020018016014012010080604020mz

O246-Trinitrophenol

26-Dinitrophenol

O24-Dinitrophenol

24-dienoate

dioic acid

2-Oxopentanoate

2-Nitrophenol

Benzene-12-diol

O4-Nitrophenol

Benzene-14-diol

Furan-25-dione

3-Oxopropanoate

Acetaldehyde

Ring cleavage

Ominus

N+Ominus

Ominus

OminusOminus

Ominus

mz = 139

mz = 108

mz = 110

mz = 157

mz = 150

mz = 115

mz = 60

H3CH3C

Hminus

mz = 98

mz = 87mz = 44

H2O + CO2

mz = 44

minusNH2

minusCO2

mz = 157

mz = 171

mz = 184

mz = 139

mz = 184

mz = 108

mz = 110

Acknowledgments

References

2O3 Formation

2O3nano-

2nano-

2rdquo

ISRN Corrosion

Advances in

ISRN Ceramics

Volume 2013

MaterialsJournal of

Journal of

ISRN Nanotechnology

01 2 3 4 5 6 7 8

h (eV)

(120572h)2

(cmminus1

1E + 10

8E + 09

6E + 09

4E + 09

2E + 09

Organic pollutant

Intermediates

Organic pollutant

Intermediates

CO2 + H2O

Ca3Al2O6

OHminus

eminus∙Ominus

O2minus

(Figure 11(b))

2in the presence of

2O3sdotCaO nanocat-

(a) (b)

12 14 16 18 20 22Time (min)

minus05

minus1

minus15

minus2

minus25

minus3

ndashAinfin

010 12 14 16 18 20 22

Time (min)

minus05

minus1

minus15

minus2

minus25

minus3

minus35

minus4

minus45

ndashAinfin

surface

Surfactant (SDS)

Ominus

Ca2+OHminus

OHminus

ClminusClminus

Clminus

2O3sdotCaO

0 0002 0004 0006 0008 001 0012 0014Surfactant (M)

ldquokrdquo v

(minminus1)

Al2O3middotCaO

00 75 100 125 150

Time (min)

4 Conclusion

minus500

minus1000

minus1500

minus2000

minus2500

minus1000

minus2000

minus3000

minus4000

00 25 50 75 100

Time (min)

67 77 94 108 150121 134 192 206

24022020018016014012010080604020mz

43 60 73

115129

157 171213

24022020018016014012010080604020mz

55 67 8195

110149

123137 192 209Inte

24022020018016014012010080604020mz

O246-Trinitrophenol

26-Dinitrophenol

O24-Dinitrophenol

24-dienoate

dioic acid

2-Oxopentanoate

2-Nitrophenol

Benzene-12-diol

O4-Nitrophenol

Benzene-14-diol

Furan-25-dione

3-Oxopropanoate

Acetaldehyde

Ring cleavage

Ominus

N+Ominus

Ominus

OminusOminus

Ominus

mz = 139

mz = 108

mz = 110

mz = 157

mz = 150

mz = 115

mz = 60

H3CH3C

Hminus

mz = 98

mz = 87mz = 44

H2O + CO2

mz = 44

minusNH2

minusCO2

mz = 157

mz = 171

mz = 184

mz = 139

mz = 184

mz = 108

mz = 110

Acknowledgments

References

2O3 Formation

2O3nano-

2nano-

2rdquo

ISRN Corrosion

Advances in

ISRN Ceramics

Volume 2013

MaterialsJournal of

Journal of

ISRN Nanotechnology

(a) (b)

12 14 16 18 20 22Time (min)

minus05

minus1

minus15

minus2

minus25

minus3

ndashAinfin

010 12 14 16 18 20 22

Time (min)

minus05

minus1

minus15

minus2

minus25

minus3

minus35

minus4

minus45

ndashAinfin

surface

Surfactant (SDS)

Ominus

Ca2+OHminus

OHminus

ClminusClminus

Clminus

2O3sdotCaO

0 0002 0004 0006 0008 001 0012 0014Surfactant (M)

ldquokrdquo v

(minminus1)

Al2O3middotCaO

00 75 100 125 150

Time (min)

4 Conclusion

minus500

minus1000

minus1500

minus2000

minus2500

minus1000

minus2000

minus3000

minus4000

00 25 50 75 100

Time (min)

67 77 94 108 150121 134 192 206

24022020018016014012010080604020mz

43 60 73

115129

157 171213

24022020018016014012010080604020mz

55 67 8195

110149

123137 192 209Inte

24022020018016014012010080604020mz

O246-Trinitrophenol

26-Dinitrophenol

O24-Dinitrophenol

24-dienoate

dioic acid

2-Oxopentanoate

2-Nitrophenol

Benzene-12-diol

O4-Nitrophenol

Benzene-14-diol

Furan-25-dione

3-Oxopropanoate

Acetaldehyde

Ring cleavage

Ominus

N+Ominus

Ominus

OminusOminus

Ominus

mz = 139

mz = 108

mz = 110

mz = 157

mz = 150

mz = 115

mz = 60

H3CH3C

Hminus

mz = 98

mz = 87mz = 44

H2O + CO2

mz = 44

minusNH2

minusCO2

mz = 157

mz = 171

mz = 184

mz = 139

mz = 184

mz = 108

mz = 110

Acknowledgments

References

2O3 Formation

2O3nano-

2nano-

2rdquo

ISRN Corrosion

Advances in

ISRN Ceramics

Volume 2013

MaterialsJournal of

Journal of

ISRN Nanotechnology

surface

Surfactant (SDS)

Ominus

Ca2+OHminus

OHminus

ClminusClminus

Clminus

2O3sdotCaO

0 0002 0004 0006 0008 001 0012 0014Surfactant (M)

ldquokrdquo v

(minminus1)

Al2O3middotCaO

00 75 100 125 150

Time (min)

4 Conclusion

minus500

minus1000

minus1500

minus2000

minus2500

minus1000

minus2000

minus3000

minus4000

00 25 50 75 100

Time (min)

67 77 94 108 150121 134 192 206

24022020018016014012010080604020mz

43 60 73

115129

157 171213

24022020018016014012010080604020mz

55 67 8195

110149

123137 192 209Inte

24022020018016014012010080604020mz

O246-Trinitrophenol

26-Dinitrophenol

O24-Dinitrophenol

24-dienoate

dioic acid

2-Oxopentanoate

2-Nitrophenol

Benzene-12-diol

O4-Nitrophenol

Benzene-14-diol

Furan-25-dione

3-Oxopropanoate

Acetaldehyde

Ring cleavage

Ominus

N+Ominus

Ominus

OminusOminus

Ominus

mz = 139

mz = 108

mz = 110

mz = 157

mz = 150

mz = 115

mz = 60

H3CH3C

Hminus

mz = 98

mz = 87mz = 44

H2O + CO2

mz = 44

minusNH2

minusCO2

mz = 157

mz = 171

mz = 184

mz = 139

mz = 184

mz = 108

mz = 110

Acknowledgments

References

2O3 Formation

2O3nano-

2nano-

2rdquo

ISRN Corrosion

Advances in

ISRN Ceramics

Volume 2013

MaterialsJournal of

Journal of

ISRN Nanotechnology

0 0002 0004 0006 0008 001 0012 0014Surfactant (M)

ldquokrdquo v

(minminus1)

Al2O3middotCaO

00 75 100 125 150

Time (min)

4 Conclusion

minus500

minus1000

minus1500

minus2000

minus2500

minus1000

minus2000

minus3000

minus4000

00 25 50 75 100

Time (min)

67 77 94 108 150121 134 192 206

24022020018016014012010080604020mz

43 60 73

115129

157 171213

24022020018016014012010080604020mz

55 67 8195

110149

123137 192 209Inte

24022020018016014012010080604020mz

O246-Trinitrophenol

26-Dinitrophenol

O24-Dinitrophenol

24-dienoate

dioic acid

2-Oxopentanoate

2-Nitrophenol

Benzene-12-diol

O4-Nitrophenol

Benzene-14-diol

Furan-25-dione

3-Oxopropanoate

Acetaldehyde

Ring cleavage

Ominus

N+Ominus

Ominus

OminusOminus

Ominus

mz = 139

mz = 108

mz = 110

mz = 157

mz = 150

mz = 115

mz = 60

H3CH3C

Hminus

mz = 98

mz = 87mz = 44

H2O + CO2

mz = 44

minusNH2

minusCO2

mz = 157

mz = 171

mz = 184

mz = 139

mz = 184

mz = 108

mz = 110

Acknowledgments

References

2O3 Formation

2O3nano-

2nano-

2rdquo

ISRN Corrosion

Advances in

ISRN Ceramics

Volume 2013

MaterialsJournal of

Journal of

ISRN Nanotechnology

O246-Trinitrophenol

26-Dinitrophenol

O24-Dinitrophenol

24-dienoate

dioic acid

2-Oxopentanoate

2-Nitrophenol

Benzene-12-diol

O4-Nitrophenol

Benzene-14-diol

Furan-25-dione

3-Oxopropanoate

Acetaldehyde

Ring cleavage

Ominus

N+Ominus

Ominus

OminusOminus

Ominus

mz = 139

mz = 108

mz = 110

mz = 157

mz = 150

mz = 115

mz = 60

H3CH3C

Hminus

mz = 98

mz = 87mz = 44

H2O + CO2

mz = 44

minusNH2

minusCO2

mz = 157

mz = 171

mz = 184

mz = 139

mz = 184

mz = 108

mz = 110

Acknowledgments

References

2O3 Formation

2O3nano-

2nano-

2rdquo

ISRN Corrosion

Advances in

ISRN Ceramics

Volume 2013

MaterialsJournal of

Journal of

ISRN Nanotechnology

Acknowledgments

References

2O3 Formation

2O3nano-

2nano-

2rdquo

ISRN Corrosion

Advances in

ISRN Ceramics

Volume 2013

MaterialsJournal of

Journal of

ISRN Nanotechnology

2nano-

2rdquo

ISRN Corrosion

Advances in

ISRN Ceramics

Volume 2013

MaterialsJournal of

Journal of

ISRN Nanotechnology

ISRN Corrosion

Advances in

ISRN Ceramics

Volume 2013

MaterialsJournal of

Journal of

ISRN Nanotechnology

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