Author's Accepted Manuscript

Biosynthesis and characterization of Phytomediated zinc oxide nanoparticles: A greenchemistry approach

P. Vanathi, P. Rajiv, S. Narendhran, SivarajRajeshwari, Pattanathu Ksm rahman, Rajen-dran Venckatesh

PII: S0167-577X(14)01279-8DOI: http://dx.doi.org/10.1016/j.matlet.2014.07.029Reference: MLBLUE17361

To appear in: Materials Letters

Received date: 5 April 2014Revised date: 26 June 2014Accepted date: 5 July 2014

Cite this article as: P. Vanathi, P. Rajiv, S. Narendhran, Sivaraj Rajeshwari,Pattanathu Ksm rahman, Rajendran Venckatesh, Biosynthesis and character-ization of Phyto mediated zinc oxide nanoparticles: A green chemistryapproach, Materials Letters, http://dx.doi.org/10.1016/j.matlet.2014.07.029

This is a PDF file of an unedited manuscript that has been accepted forpublication. As a service to our customers we are providing this early version ofthe manuscript. The manuscript will undergo copyediting, typesetting, andreview of the resulting galley proof before it is published in its final citable form.Please note that during the production process errors may be discovered whichcould affect the content, and all legal disclaimers that apply to the journalpertain.

www.elsevier.com/locate/matlet

1

Biosynthesis and characterization of phyto mediated zinc oxide nanoparticles: A green chemistry approach

P. Vanathi a, P. Rajiv a, S. Narendhran a, Sivaraj Rajeshwari a*,

Pattanathu KSM Rahman b, Rajendran Venckatesh c

a Department of Biotechnology, School of Life Sciences, Karpagam University,

Eachanari post, Coimbatore 641 021, Tamil Nadu, India. b School of science and Technology, University of Teesside, Middlesbrough- TS13BA,

UK. c Department of Chemistry, Government Arts College, Udumalpet 642 126, Tamil Nadu,

India.

* Corresponding author e-mail id: rajeshwarishivaraj@gmail.com

Tel./fax: +91 4222611146

Abstract

In this study, we describe synthesis and characterization of zinc oxide

nanoparticles from aquatic weed by a green chemistry approach. The aim of this work is

to synthesize zinc oxide nanoparticles from Eichhornia crassipes leaf extract by low cost

technology as against the other available technique and eco-friendly method. Aqueous

leaf extract acts as a reducing and capping agent in during synthesis of nanoparticles.

Formation of zinc oxide nanoparticles, optical properties, size and morphology has been

analyzed by UV–Vis spectrophotometer, XRD, SEM with EDX and TEM. SEM and

TEM analysis show that zinc oxide nanoparticles were spherical shape and average

particles size in 32 ± 4 nm. Biological method for synthesis of zinc oxide nanoparticles

using plant extracts has been suggested as a possible eco-friendly alternative to chemical

and physical methods.

Keywords: Eichhornia, nanoparticles, SEM, TEM, zinc oxide

1. Introduction

Zinc oxide is a unique material that exhibits semiconducting, piezoelectric, and

pyro electric properties and has versatile applications in transparent electronics,

2

ultraviolet (UV) light emitters, piezoelectric devices, chemical sensors, spin electronics,

personal care products, coating and paints [1-3]. Zinc oxide nanoparticles have been

used in many industrial areas such as UV light-emitting devices, solar cells, photo

catalysts, gas sensors, cosmetic and pharmaceutical industries [4–8]. Zinc oxide particles

can be produced by several techniques such as chemical precipitation [9, 10], spray

pyrolysis [11], sol–gel [12], thermal decomposition [13], and hydrothermal synthesis

[14–17] electrochemical and photochemical reduction techniques [18, 19]. Increasing

awareness towards green chemistry has led to the development of an eco-friendly

approach for the synthesis of metal oxide nanoparticles. Plants and/or their extracts

provide a biological synthesis route of several metallic nanoparticles which are more eco-

friendly and allows a controlled synthesis with well-defined size and shape [20]. The

enzymes [21], leaf extract [22] and bacteria [23] play a vital role in green synthesis of

zinc oxide nanoparticles. E. crassipes (Family: Pontederiaceae) is one of the worst

aquatic weeds of the world. It is successfully resistant to all attempts of eradication

methods (chemical, biological, mechanical, or hybrid means) [24]. Therefore, a nano

biotechnology approach has been used to solve the problem of aquatic weed disposal and

management.

2. Materials and methods

2.1. Materials

E. crassipes plants were collected from Kurichi Lake, Kurichi, Coimbatore, Tamil

Nadu, India (11˚16’N; 76˚58’E). All the chemicals were bought from Sigma-Aldrich

chemicals, India. Laboratory glass wares were soaked overnight in acid cleaning solution

and washed thoroughly in tap and distilled water. Milli-Q water has been used for

synthesis of nanoparticles.

2.2. Synthesis of zinc oxide nanoparticles using E. crassipes leaf extract

Five gram of (fresh) E. crassipes leaves were weighed and washed with tap water,

followed by distilled water. Samples were ground well by mortar and pestle using de-

ionized water. Aqueous leaf extract was heated at 65 ºC for 15 min. After cooling, the

3

leaf extract was filtered using filter paper (Whatman No. 42, Maidstone, England) and

store in refrigerator for further investigation.

Green synthesized zinc oxide nanoparticles were synthesized through reduction of

zinc nitrate by leaf extract, which acts as a capping agent, as described by Rajiv et al.

[22]. 50% of the leaf extract was stirred at 60 ºC for 1 h. The precursor solution (250

ml) (zinc nitrate) was added drop wise under continuous stirring. The mixture of the

solution was stirred at 100ºC for 6 hrs. End of this step, yellow color precipitate was

obtained. The precipitate was washed with ethanol two times, followed by annealing at

400 ºC for 1 h. Finally, white powder was obtained, stored in properly labeled containers

and used for the further analysis.

2.3. Characterization of zinc oxide nanoparticles

Optical property of zinc oxide nanoparticles was analyzed by UV-absorption

spectra (Shimadzu). X–Ray diffraction (Perkin–Elmer) was used for identification, purity

and quantitative analysis of various forms of zinc oxide nanoparticles in range from 20º

to 80º Cu Kα radiations (k = 0.15406 nm). Shape and morphology of zinc oxide

nanoparticles were characterized by Scanning Electron Microscopy (Model

JSM6390LV). Elemental analysis of zinc oxide was examined using Energy dispersive

X-ray analysis (RONTEC’S EDX system). The average size and distribution of sample

was examined by Transmission Electron Microscopy (JEOL JEM-3100F).

3. Results and discussion 3.1. Characterization of zinc oxide nanoparticles 3.1.1. UV- Vis analysis

UV- Visible absorption spectra of zinc oxide nanoparticle is shown in Figure 1a.

UV-Visible absorption spectra reveal that zinc oxide nanoparticles are mono dispersed.

Zinc oxide nanoparticles show a broad absorption peak at 378 nm. The band gap of zinc

oxide nanoparticles was calculated by using formula E = hc/λ, where ‘h’ is plank’s

constant, ‘c’ is the velocity of light and ‘λ’ is the wavelength. The band gap of zinc oxide

was found to be 3.32 eV, as has been reported earlier [25].

4

3.1.2. XRD analysis

X - ray diffraction was done to confirm the phase of zinc oxide nanoparticles. The

peaks at 2θ values of 31.80°, 34.44°, 36.27°, 47.57°, 56.6°, 62.88°, 67.90° and 69.11°

corresponded to the crystal planes of (100), (002), (101), (102), (110), (103), (112) and

(202) of zinc oxide nanoparticles. The diffraction peaks could be referring as spherical

phase, which was evaluated with the data from JCPDS card No. 89-7102. The strong and

narrow peak denotes that the product has well crystalline nature of particles (Figure 1b).

The particle average size was calculated by the Scherrer formula and found to be in the

range of 32 nm [26].

3.1.3. SEM / EDAX analysis

The SEM images of zinc oxide nanoparticles are shown in Fig. 2a. From the

images it is evident that the morphology of zinc oxide nanoparticles was spherical shaped

and well distributed without aggregation, which is very similar to earlier studies [23].

Analysis through energy dispersive X-ray (EDX) spectrometer confirmed the presence of

zinc oxide nanoparticles (Fig. 2b). The vertical axis displays the number of X-ray counts

whilst the horizontal axis displays energy in keV. Identification lines for the major

emission energies for zinc are 81.81 % and oxygen 18.19% these corresponds with peak

in the spectrum, thus giving that zinc has been correctly identified. This is very similar to

Jayaseelan et al. [23] and Rajiv et al. [22].

3.1.4. TEM analysis

TEM image reports the shape of zinc oxide nanoparticles is spherical.The typical

transmission electron micrograph of the phyto mediated zinc oxide nanoparticles are

shown in Figure 2c and d. The average particle sizes is 32 ± 4 nm, which is in good

agreement with the particle size calculated from XRD analysis.This is similar to,

synthesis of zinc oxide nanoparticles (27 ± 5 nm) from Parthenium hysterophorus leaf

[22].

5

4. Conclusion

We have demonstrated the synthesis of zinc oxide nanoparticles using a simple,

eco-friendly and green chemistry approach. E. crassipes leaf aqueous extracts have been

used as a reducing and capping agent for the synthesis of zinc oxide nanoparticles.

Acknowledgements

We thank to Management of Karpagam University, Coimbatore, Tamil Nadu,

India for providing necessary facilities to carry out this work.

References

[1]. Wang ZL. Nanostructures of zinc oxide. Mater Today 2004; 7:26–33.

[2] Wahab R, Kim YS, Lee DS, Seo JM, Shin HS. Controlled synthesis of zinc oxide

nanoneedles and their transformation to microflowers. Sci Adv Mater 2010; 2:35–

42.

[3] Akhtar MS, Ameen S, Ansari SA, Yang O. Characterization of ZnO nanorods and

balls nano materials for dye sensitized solar cells. J Nanoeng Nanomanuf 2011; 1:71–6.

[4] Deng Z, Chen M, Gu G, Wu LM. A facile method to fabricate ZnO hollow spheres

and their photocatalytic property. J Phys Chem B 2008; 112:16-22.

[5] Yang SJ, Park CR. Facile preparation of monodisperse ZnO quantum dots with high

quality photoluminescence characteristics. Nanotechnology 2008; 19:035609.

[6] Krishnakumar T, Jayaprakash R, Pinna N, Singh VN, Mehta BR, Phani AR.

Microwave-assisted synthesis and characterization of tin oxide nanoparticles. Mater Lett

2008; 63:242-5.

[7] Cao B, Cai W. From ZnO nanorods to nanoplates: chemical bath deposition growth

and surface-related emission. J Phys Chem C 2008; 112:680- 5.

[8] Li M, Bala H, Lv X, Ma X, Sun F, Tang L, Wang Z. Direct synthesis of

monodispersed ZnO nanoparticles in an aqueous solution. Mater Lett 2007; 61:690-3.

[9] Zhong OP, Matijevic E. Preparation of uniform zinc oxide colloids by controlled

double-jet precipitation. J Mater Chem 1996; 3:443-7.

[10] Lingna W, Mamoun M. Synthesis of zinc oxide nanoparticles with controlled

morphology. J Mater Chem 1999; 9:2871- 8.

6

[11] Liu T-Q, Sakurai O, Mizutani N, Kato M. Preparation of spherical fine ZnO particles

by the spray pyrolysis method using ultrasonic atomization technique. J Mater Sci 1986;

21:3698–702.

[12] Bahnemann DW, Kormann C, Hoffmann MR. Preparation and characterization of

quantum size zinc oxide: a detailed spectroscopic study. J Phys Chem 1987; 91:3789.

[13] Andres-Verges M, Martinez-Gallego M. Spherical and rod- like zinc oxide

microcrystals: morphological characterization and microstctural evoluation with

temperature. J Mater Sci 1992; 27:3756– 62.

[14] Sue K, Murata K, Kimura K, Arai K. Continuous synthesis of zinc oxide

nanoparticles in supercritical water. Green Chem 2003; 5:659–62.

[15] Sue KW, Kimura K, Yamamoto M, Arai K. Rapid hydrothermal synthesis of ZnO

nanorods without organics. Mater Lett 2004; 58:3350– 2.

[16] Ohara S, Mousavand T, Umetsu M, Takami S, Adschiri T, Kuroki Y, Takata M.

Hydrothermal synthesis of fine zinc oxide particles under supercritical conditions. Solid

State Ionics 2004; 172:261– 4.

[17] Ohara S, Mousavand T, Sasaki T, Umetsu M, Naka T, Adschiri T. Continuous

production of fine zinc oxide nanorods by hydrothermal synthesis in supercritical water. J

Mater Sci 2008; 43:2393– 6.

[18] Chen W, Cai W, Zhang L, Wang G. Sonochemical processes and formation of gold

nanoparticles within pores of mesoporous silica. J Colloid Interface Sci 2001; 238:291-5.

[19] Frattini A, Pellegri N, Nicastro D, Sanctis OD. Effect of amine groups in the

synthesis of Ag nanoparticles using aminosilanes. Mater Chem Phys 2005; 94:148-152.

[20] Bar H, Bhui DK, Sahoo GP, Sarkar P, Pyne S, Misra A. Green synthesis of silver

nanoparticles using seed extract of Jatropha curcas. Colloids Surf Physiochem Eng

Aspects 2009; 348:212– 6.

[21] Prasad K, Jha AK. ZnO nanoparticles: synthesis and adsorption study. Nat Sci 2009;

1:129–35.

[22] Rajiv P, Rajeshwari S, Venckatesh R. Bio-Fabrication of zinc oxide nanoparticles

using leaf extract of Parthenium hysterophorus L. and its size-dependent antifungal

activity against plant fungal pathogens. Spectrochim Acta Part A 2013; 112:384–87.

7

[23] Jayaseelan C, Abdul Rahuman A, Vishnu Kirthi A, Marimuthu S, Santhoshkumar T,

Bagavan A, Gaurav K, Karthik L, Bhaskara Rao KV. Novel microbial route to synthesize

ZnO nanoparticles using Aeromonas hydropila and their activity against pathogenic

bacteria and fungi. Spectrochim Acta Part A 2012; 90: 78–84.

[24] Abbasi SA, Ramasamy EV. In: Biotechnological methods of pollution control, orient

longman (Universities press India Ltd), Hyderabad, 1999, p.168.

[25] Nawaz HR, Solangi BA, Zehra B, Nadeem U. Preparation of nano zinc oxide and its

application in leather as a retanning and antibacterial agent. J Sci Ind Res 2011; 2:164–

170.

[26] Borchert H, Shevchenko EV, Robert A, Mekis I, Kornowski A, Grabel G, Weller H.

Determination of nanocrystal sizes: a comparison of TEM, SAXS, and XRD studies of

highly monodisperse CoPt particles. Langmuir 2005; 21:1931–36.

[27] Nakamoto K. Infrared and raman spectra of inorganic and coordination compounds.

3rd ed. Wiley, Chichester, New York, 1978.

8

Highlights

• Phyto mediated nanoparticle synthesis method is simple and cost effective.

• Phyto mediated zinc oxide nanoparticles are eco-friendly.

• Aquatic weed plant leaf extract acts as a capping agent.

• Highly stable, spherical zinc oxide nanoparticles are synthesized.

Graphical Abstract

20 40 60 80

0

2000

4000

6000

8000

10000

12000

Inte

nsity

2 Theta (Degree)

202

004

20111

220

0

103

110

102

101

100

002

Graphical Abstract (for review)

Figure 1. A. UV-Vis spectra and B. XRD spectra of phyto mediated zinc oxide nanoparticles

synthesized from Eichhornia crassipes.

Figure 2. A. SEM, B. EDX, C. TEM and D. SAED pattern analysis of phyto mediated zinc

oxide nanoparticles synthesized from Eichhornia crassipes.

A B

Figure