Simple and direct synthesis of zinc vanadate ZnV2O5 nanocrystals for its electrocatalytic andantimicrobial activity

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Journal of Chemical and Pharmaceutical Research, 2017, 9(12):18-24
Research Article
ISSN : 0975-7384
CODEN(USA) : JCPRC5
18
Simple and Direct Synthesis of Zinc Vanadate (ZnV2O5) Nanocrystals for its
Electrocatalytic and Antimicrobial Activity
Arvind Singh K Heer*
Department of Chemistry, Bhavan’s College, Mumbai, Maharashtra, India
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ABSTRACT
Zinc Vanadate (ZnV2O5) Nanocrystals were prepared by two steps, ceramic route process. Optimization of the
ceramic route processing conditions enhances the Electrocatalytic and Antimicrobial performance of the prepared
nanoparticles. The thermally treated material was subjected to XRD, FTIR, UV-Visible spectroscopy, SEM and
EDS, which confirmed the formation of Zinc Vanadate (ZnV2O5) Nanocrystals. The electrochemical detection of
Anthracene by Zinc Vanadate nanoparticles was investigated by Cyclic Voltammetry. The result concludes that the
ZnV2O5 NPs have higher activity for detection and oxidation of Anthracene. The as synthesized ZnV2O5 NPs were
found to exhibit strong antimicrobial activity against both Escherichia coli (E.coli) gram negative and
Staphylococcus aureus (S. aureus) gram positive microorganisms implying their strong potential as antimicrobial
agent.
Keywords: ZnV2O5 Nanocrystals; Antimicrobial activity; Escherichia coli; Staphylococcus aureus; Thermal
decomposition; Electrocatalytic activity; Anthracene
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INTRODUCTION
Nanostructured materials have been widely investigated for the fundamental scientific and technological interests in
accessing new classes of functional materials with unprecedented properties and applications [1-3]. In recent years,
there has been an increasing interest in the synthesis of nanosized crystalline metal-metal oxides because of their
large surface areas, unusual adsorptive properties, surface defects and fast diffusivities. ZnV2O5 is a very important
material extensively used in catalysis, gas sensors, electrochromic films, battery cathodes, heterogeneous catalytic
materials and magnetic materials [4,5]. Due to their small size, nanoparticles exhibit novel material properties that
are significantly different from those of their bulk counterparts.
The metal-metal oxide semiconductors have been extensively explored by researchers in pure and doped form.
Doping introduces remarkable changes in the structural, optical, electrical, magnetic, and semiconducting properties
which encourage their use in various applications, namely, sensors and piezoelectric, photovoltaic, electro-optic, and
micro-electromechanical devices [6-10]. Zinc Vanadate (ZnV2O5) is a multifunctional material with wide band gap
(3.23 eV), n-type hexagonal structured, high electron mobility, large piezoelectric constants, high nonlinear optical
coefficients, radiation hardness, biocompatibility, and large 60 meV exciton binding energy characteristics. It is
suitable for small wavelength optoelectronic devices. The anti-microbial activity of nanoaparticles has been
correlated to their ability to interact or penetrate the cell wall of bacteria and generation of reactive oxygen species
(ROS) [11-13].The antimicrobial activity of ZnV2O5 has been studied by various research groups on variety of
micro-organisms. ZnV2O5 have been found to be effective against gram positive, gram negative and some of the
multi-resistant strains such as Staphylococcus aureus, Escherichia coli, Salmonella enteric, methicillin-resistant
Staphylococcus aureus [14-18].
In the present study, we have investigated a simple and rapid route to synthesize Zinc Vanadate nanocrystals using
Zinc Oxide and Ammonium meta-Vanadate. The whole process takes only a few hours to yield Zinc Vanadate

ASK Heer J. Chem. Pharm. Res., 2017, 9(12):18-24
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19
nanoparticles. The structure, morphology and optical properties of the synthesized Zinc Vanadate nanoparticles have
been investigated by XRD, FT-IR, UV- Visible spectroscopy and SEM with EDS. In addition, the electrocatalytic
oxidation ability of zinc vanadate in the Cyclic Voltammeter has been investigated, for the Oxidation of Anthracene
to Anthraquinone. It’s anti-microbial activity on gram negative Escherichia coli (E.coli) gram negative and
Staphylococcus aureus (S. aureus) gram positive microorganisms. The anti-microbial experiments were carried out
using Kirby-Bauer disc diffusion method.
EXPERIMENTAL SECTION
Synthesis of ZnV2O5 Nanocrystals
0.008 mole of Ammonium meta-Vanadate (NH4VO3) and 0.004 mole of Zinc Oxide (ZnO) were weighed and mixed
in an agate mortar and pestle for 1 hr initially. The obtained powder was ball milled in agate grinding jar using agate
ball for 2 hr to achieve better homogeneity. After milling the mixed powder was dried in an oven at 80°C for 20mins
and was transferred to Quartz crucible for calcination. The powder was calcined at 550°C in an horizontal furnace
for 6 hrs. Then obtained material was subjected to further Structural characterization, Electrocatalysis and
Antimicrobial activity [19-23].
Materials and Structural Characterization
Synthesizing ZnV2O5 nanostructure in this research includes the use of several materials such as Zinc Oxide (ZnO)
≥ 99% purity (Sigma aldrich) and Ammonium meta-Vanadate (NH4VO3) ≥ 99% purity (Sigma aldrich). The crystal
structure of ZnV2O5 nanoparticles was analyzed by a PANalytical Empyrean 300TT X-ray diffractometer with Cu-Kα1
radiation (λ=1.5406 Å). FT-IR spectrum of the ZnV2O5 was recorded on Perkin Elmer FT-IR 8300 series instrument by
using potassium bromide pellets. The morphology of the materials was analyzed by SEM HITACHI SU6600 scanning
electron microscopy and energy dispersive spectroscopy respectively. UV-Vis spectral analysis was done by using UV-
Visible spectrophotometer (UV-1100, India). UV-Visible absorption spectrophotometer with a resolution of 5 nm
between 200 and 600 nm was used. The electrochemical experiments were performed on a CHI 600A electrochemical
instrument using the as-modified electrode and bare GCE as working electrode, a platinum wire was the counter
electrode, and saturated calomel electrode (SCE) was the reference electrode [23].
Antimicrobial Activity of Zinc Vanadate Nanoparticles
The anti-microbial activity of ZnV2O5 NPs was studied using Kirby-Bauer disc diffusion method. The anti-bacterial
activity of ZnV2O5 NPs was studied against gram negative E.coli and gram positive S. aureus bacteria. The plates
containing Luria Bertani (LB) agar medium were sterilized and solidified. Approximately 106 colony forming units
(CFU) were spread on LB agar plates to cultivate the bacteria. The sterilized filter paper discs of 5 mm diameter
were dipped in ZnV2O5 NPs solutions of varying concentrations (1–3 µg/ml) and placed in agar plates. One disc was
dipped in 1 mM ZnO solution and considered as control. The plates were then incubated at 37°C for 24 hours. The
zones of inhibition for control and ZnV2O5 NPs were measured. The experiments were repeated thrice and the
average was taken.
Electrode Modification
Ultrasonically dispersed ZnV2O5 nanopowder in 5 mL of water was drop coated onto the GCE and dried at room
temperature. The ZnV2O5 coated electrode prepared by electrochemical deposition techniques and used for
electrocatalytic reduction of Anthracene. CV’s were run in electrochemical cell containing 50 mL DD water and 0.1
M KOH in presence of SCE reference electrode and Platinum wire as counter electrode.
RESULTS AND DISCUSSION
Synthesis of ZnV2O5 Nanocrystals
The probable mechanism for the synthesis of prepared ZnV2O5 nanocrystals is as follows:
The Synthesis of ZnV2O5 nanocrystals was carried out by taking 0.04 moles of Zinc Oxide powder and 0.008 moles
of Ammonium meta-Vanadate in mortar pestle and was grinded for 2 hrs which results in formation of white colored
precursor. Then the obtained material was calcined at 500°C for 24hrs and it was noticed that after 2 hrs the white
colored precursor starts turning dark red in color. This change in color was due to reduction of ZnO and NH4VO3 to
ZnV2O5 nanoparticle as one of the properties of Nanoparticles [19] and the smell of ammonia was observed during

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calcination and grinding which was considered as the evaporation of ammonium group from the reaction system.
XRD Analysis
XRD pattern of synthesized ZnV2O5 nanoparticles by ceramic route method is shown in Figure 1. The XRD pattern
shows a high crystallinity of ZnV2O5 sample level with diffraction angles of 12.3°, 27.4°, 28.3° and 51.8°, which
correspond to the characteristic face centered cubic (FCC) of ZnV2O5 lines indexed at (111), (200), (210) and (222),
respectively. The size of the nanoparticles obtained were estimated to be 77 nm using Debye-Scherrer Equation,
which may indicate a high surface area, and surface area to volume ratio of the nano-crystals. The equation is
written below:
d = K λ
β Cos()
Where K, known as Scherer’s constant (shape factor), ranges from 0.9 to 1.0, λ is 1.5418 Å, which is the wavelength
of the X-Ray radiation source, β1/2 is the width of the XRD peak at half height and  is the Bragg angle.
Figure 1: XRD analysis of ZnV2O5 nanocrystals
FTIR Analysis
FT-IR spectrum of ZnV2O5 nanoparticles (Figure 2) showed significant absorption peaks at 1607, 3480, 647, 1635
and 1428 cm−1
. The absorption band at 1607 cm−1
was assigned to M-O stretching vibration mode [20] and 647 cm−1
was assigned to the bridging vibration of O-M-O bond [21]. The weak band near 1635 cm−1
is assigned to H-O-H
bending vibration mode were presented due to the adsorption of moisture, when FTIR sample disks were prepared in an
open air atmosphere. These observations provided the evidence for the presence of hydration in the structure [22] band
near 3480 cm−1
due to the OH-stretching vibrations of free and hydrogen-bonded hydroxyl groups. The formation of
ZnO phase present in tetrahedron unit of vanadates is characterized by an intense and very broad IR band with poor
resolved shoulders at 1428 cm−1
[23].
Figure 2: FTIR Analysis of ZnV2O5 nanocrystals
UV-Visible Spectroscopy Analysis
The energy band gap of nanocrystalline zinc vanadate nanocrystals was obtained from the UV-Visible spectroscopy
at room temperature and is shown in Figure 3. It displays an absorption inflection point at around 385 nm, which
should be assigned to the excitonic absorption feature of ZnV2O5. The direct band gap calculated from diffused
reflectance spectra is 3.23 eV, which is higher for nano Zinc Vanadate than that for bulk Zinc Vanadate. The

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increment of the values of optical band gap arises due to improvement in the crystallinity of during annealing
treatment [9]. The energy band gap value is reflected in the inset of (Figure 3) which comes out to be 3.21 eV, that
is, less than pure ZnO (3.37 eV). The band gap energy of V2O5 is 2.3 eV and ZnO is 3.37 eV; when V2O5 is doped in
ZnO, alloy is formed which causes decrease in band gap.
Figure 3: UV-visible spectroscopy analysis of ZnV2O5 nanocrystals
SEM and EDS Analysis
Scanning electron microscopy (SEM) has been used to identify the size, shape and morphology of nanoparticles.
The SEM micrograph of the ZnV2O5 calcined at 500°C is shown in Figure 4. It can be seen that the particles adopt
irregular morphology with different sized particle. In addition, ZnV2O5 nanoparticles show cube shape with smooth
surface. It clearly indicates the fine crystal like particles adsorbed on the surface due to the aggregation. It shows the
crystal like agglomerates were purely due to the magnetic induction between the particles. The Energy Dispersive X-
ray Spectroscopy (EDS) spectrum of the synthesised ZnV2O5 nanoparticles Figure 5. shows strong Zinc signal along
with vanadium and weak peaks of oxygen and oxides analysis by EDS confirms the formation of pentavalent
Vanadium(V2O5) and Zinc Ions (Zn+2
) i.e., ZnV2O5.
Figure 4: SEM images of ZnV2O5 nanocrystals
Figure 5: EDS analysis of ZnV2O5 nanocrystals
Electrochemical Property

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22
The electrochemical behaviour of 1 mM Anthracene at ZnV2O5/GCE was tested with cyclic voltammetric (CV)
measurements in 0.1 M KOH. Figure 6 shows the CV of ZnV2O5/GCE in KOH electrolyte. It can be seen that the
ZnV2O5 is non-electroactive in the selected potential region. Figure 6 shows broad peaks in the potential range from
−0.4 to -0.6 V. Figure 7 shows oxidation of Anthracene at ZnV2O5/GCE. It shows the cathodic peak at -0.8 V with
enhanced current response relative to that of ZnV2O5/GCE. At the same time, we have noticed that the ZnV2O5/GCE
shows higher current response at the positive potential region 0 to 0.2 V, which was indicative of the electron
transport property of Anthracene. It indicated that the ZnV2O5 were catalytically more active toward electrochemical
oxidation of Anthracene to Anthraquinone.
Figure 6: Cyclic voltammograms (CV) of (a) ZnV2O5modified GCE (b) Bare GCE forthe reduction of 0.001 M anthracene in 0.1 M KOH
electrolyte at50 mVs-1
Figure 7: Oxidation of anthracene to anthraquinone
Anti-Microbial Activity of Zinc Vanadate (ZnV2O5) nanoparticles
Zinc nanoparticles, due to their antimicrobial properties have been used most widely in the health industry,
medicine, textile coatings, food storage, dye reduction, wound dressing, antiseptic creams and a number of
environmental applications. Since ancient times, elemental Zinc and its compounds have been used as antimicrobial
agents. We have examined Zinc Vanadate (ZnV2O5) nanoparticles as possible antibacterial agents. The Zinc
Vanadate (ZnV2O5) nanoparticles were immediately tested for respective antimicrobial activities towards both gram
positive (S. aureus) and gram negative (E. coli) bacterial strains showing the zones of inhibition. Based on the zone
of inhibition produced, synthesized Zinc Vanadate (ZnV2O5) nanoparticles prove to exhibit good antibacterial
activity against E. coli and S. aureus. On the other hand, control exhibit minimum antibacterial activity. The results
of antibacterial activities of prepared Zinc Vanadate (ZnV2O5) nanoparticles evaluated from the Kirby-Bauer disc
diffusion method are given in Table 1. The Zinc Vanadate (ZnV2O5) nanoparticles showed efficient antimicrobial
property compared to other due to their extremely large surface area providing better contact with cell wall of
microorganisms (Figure 8).
Table 1: Size of the inhibition zones for ZnV2O5 against the tested microorganisms
Escherichia coli Staphylococcus aureus
Disc Sample Inhibition zone (mm) Disc Sample Inhibition zone (mm)
1 Control 1.0 µg/ml 5 1 Control 5
2 2.0 µg/ml 6 2 1.0 µg/ml 9
3 3.0 µg/ml 12 3 2.0 µg/ml 10
4 24 4 3.0 µg/ml 13

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Figure 8: Anti-microbial activity of ZnV2O5 NPs in terms of zone of inhibition created by ZnV2O5 NPs. (a) Anti-bacterial activity of
ZnV2O5 NPs against E.coli bacteria (b) Anti-bacterial activity of ZnV2O5 NPs against S. aureus bacteria
CONCLUSION
The Zinc Vanadate (ZnV2O5) nanoparticles were prepared by thermal decomposition method. FT-IR analysis
confirms the formation of the Zinc Vanadate (ZnV2O5) nanoparticles. The calcined Zinc Vanadate (ZnV2O5)
nanoparticles at 500°C were characterized by using XRD. The XRD confirms the crystal structure of the samples.
The SEM of Zinc Vanadate (ZnV2O5) nanoparticle shows the crystal agglomerated particles. The optical absorption
spectrum of Zinc Vanadate (ZnV2O5) sample was studied by UV-Visible spectroscopy. The electrochemical
detection of Anthracene by Zinc Vanadate (ZnV2O5) nanoparticles was investigated by cyclic voltammetry. The
results conclude that the Zinc Vanadate (ZnV2O5) nanoparticles have higher activity for the detection ofAnthracene.
The anti-microbial activity measurements suggest that the ZnV2O5 NPs have strong toxic potential towards bacteria
E.coli and S. aureus. The two step process makes this method easy, economically viable and useful for large scale
production.
ACKNOWLEDGEMENT
I wish to express my sincere gratitude to Bhavan’s College and Department of Chemistry, to give us chance to do
research work, Head of the Chemistry Department, Dr. Rajiv Pandit, for providing all facilities to work in
Laboratory, Special thanks to Sajid M. Mansoori for his valuable input and support for the completion of this
research work.
Conflict of Interest
The author Arvind Singh K Heer states that there is no conflict of interests regarding the publication of this paper.
REFERENCES
[1] Yu Lina; Ting Xie; B Cheng; B Geng; L Zhang. Chem Phys Lett. 2003, 380, 521-525.
[2] R Manigandan; R Suresh; K Giribabu; L Vijayalakshmi; A Stephen; V Narayanan. Adv Mater Res. 2012,
584, 263-266.
[3] H Amekura; N Umeda; Y Takeda; J Lu; N Kishimoto. Appl Phys Lett. 2004, 85, 6.
[4] MI Shiloms; AF Pshenichnikov; K Morozov; I Shurubor. J Magn Magn Mater. 1990, 85, 40-46.
[5] AS Heer; SM Mansoori; NK Chamria; SR Ingale. J Chem Cheml Sci. 2017, 7(4), 297-306.
[6] C Bergemann; M Schulte; OJ Brassard; AS Lubbe. J Magn Magn Mater. 1999, 194, 45-52.
[7] IG Dimitrov; AO Dikovska; PA Atanasov; TR Stoyanchov; T Vasilev. J Physics Conference Series. 2008,
113(1), 5.
[8] ML Grilli; A Sytchkova; S Boycheva; A Piegari. Appl Mat Sci. 2013, 210(4), 748-754.
[9] K Khun; ZH Ibupoto; CO Chey; J Lu; O Nur; M Willander. Appl Surface Sci. 2013, 268, 37-43.
[10] RA Zargar; S Chackrabarti; S Joseph; MS Khan; R Husain; A Hafiz. Optik. 2015, 126(23), 4171-4174.
[11] LB Stolle; S Hussain; JJ Schlager; MC Hofmann. Toxicol Sci. 2005, 88, 412.

_____________________________________________________________________________________________
24
[12] P Joshi; S Chakraborti; P Chakrabarti; D Haranath; V Shanker; ZA Ansari; SP Singh; V Gupta. J Nanosci
Nanotechnol. 2009, 9, 6427.
[13] P Joshi; S Chakraborti; P Chakrabarti; SP Singh; ZA Ansari; M Husain; V Shanker. Sci Adv Mater. 2012,
4, 173.
[14] A Panacek; L Kvitek; R Prucek; M Kolar; R Vecerova; N Pizurova; VK Sharma; T Nevecna; R Zboril. J
Phys Chem B. 2006, 110, 16248.
[15] P Irwin; J Martin; LH Nguyen; Y He1; A Gehring; CY Chen. J Nanobiotechnol. 2010, 8, 34.
[16] L Kvitek; A Panacek; J Soukupova; M Kolar; R Vecerova; R Prucek; M Holecova; R Zboril. J Phys Chem
C. 2008, 112, 5825.
[17] JR Morones; JL Elechiguerra; A Camacho; K Holt; J Kouri; JT Ramirez; MJ Yacaman. Nanotechnol. 2005,
16, 2346.
[18] PL Carpenter. Microbiology, WB Saunders Company, Philadelphia, 1972, 245.
[19] Nanotechnology: Principles and Practices, Springers, 2015, 15.
[20] L Estepa; M Daudon. Biospectroscopy. 1997, 3, 347-369.
[21] M Gotic; S Music; M Ivanda; M Soufek; S Popovic. J Mole Struct. 2005, 744-747, 535-540.
[22] S Radhakrishnan; SD Deshpande. Mater Lett. 2001, 48, 144.
[23] ASK Heer; N Chamria; MS Mansoori. WJPR. 2017, 7(10), 818-826.

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Simple and direct synthesis of zinc vanadate ZnV2O5 nanocrystals for its electrocatalytic andantimicrobial activity