Index Copernicus Value- 56.65
Volume||5||Issue||03||March-2017||Pages-6281-6286||ISSN(e):2321-7545
Website: http://ijsae.in
DOI: http://dx.doi.org/10.18535/ijsre/v5i03.06
Microwave Assisted Chemical Synthesis of Nickel Oxide
Authors
Anjali Maurya , Dr.Nanda Bhatia2, Dr.Vijay Varma3
1
Dr.H.S Gour Central University, Sagar, India
2
B.L.P.Govt.P.G.College MHOW,D.A.V.V. Indore
3
Dr.H.S Gour Central University, Sagar, India
Email: [email protected], [email protected] [email protected]
Corrosponding Author:
Dr. Nanda Bhatia
Email: [email protected]
ABSTRACT
Nickel Oxide (NiO) nanoparticles have been synthesized by Microwave assisted chemical synthesis
method by using the precursors NiCl2 and NaHCO3. It is a simple, novel and cost effective method. The
structure, morphology and crystalline phase of the nickel oxide nanocrystals have been investigated by
scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction
(XRD).Presence of functional groups and optical characters are analyzed by using FTIR and UV- visible
techniques.
Keywords- Microwave, Crystalline, Nanoparticles, X Ray Diffraction.
1
1. INTRODUCTION
Nickel (II) oxide is the chemical compound with the formula NiO. Nickel oxide is a powdery green solid
that becomes yellow on heating. It is readily soluble in acids but insoluble in hot and cold water. Its melting
point is 1955 °C. The mineralogical form of NiO, bunsenite, is very rare. It is classified as a basic metal
oxide. NiO belongs to NaCl structure, so-called rock salt structure. The space group of NaCl structured NiO
is Fm3m with lattice parameters a = 4.1769 Å (JCPDS, 47-1049). ‘NiO’ is often non-stoichiometric. The
nonstoichiometry is accompanied by a color change from green to black due to the existence of Ni
3+
resulting from Ni vacancies [1]. This leads to p-type conductivity.
Nickel oxide is a promising material for applications in fuel cells [2] and catalysis [3]. Non-stoichiometric
nickel oxide, because of its defect structure is a p- type semiconductor and finds application as gas sensor
for H2 [4]. As the Neel temperature of NiO is 523 K, it can be applied for room temperature spin valve
devices [5].
Different methods have been reported for the synthesis of NiO nanoparticles such as evaporation [6-7],
magnetron sputtering [8-9], and sol-gel [10]. Among various methods for controlled synthesis, the soft
chemical route, based on solution process was used here to prepare single crystalline, defect free,
nonspherical shaped NiO nanoparticles. The soft chemical approach can be defined as producing
nanomaterials through chemical reduction under mild conditions in the presence of chemical additives. The
advantage of soft chemical route is that microcrystal can be synthesized at a considerably lower temperature
along with energy saving and cost effectiveness. Synthesis via microwave-assisted routes is simple, energy
efficient and time saver. Its utilization results in rapid volumetric heating, high selectivity and great product
yield [11-12].
Anjali Maurya et al IJSRE Volume 05 Issue 03 March 2017
Page 6281
2. EXPERIMENTAL
Reagents are all of AR grade Nickel oxide was synthesized by dissolving 18.4g of NiCl 2 in 80ml distilled
water and 12g of NaHCO3 was dissolved in 80ml of distilled water in a separate container. The nickel
chloride solution was stirred for 15 minutes at room temperature on a magnetic stirrer. Then the sodium
bicarbonate solution was added to the nickel chloride solution drop by drop with constant stirring. After 15
minutes the precipitate was collected by decantation and filtered with the help of Watman filter paper and
was washed thoroughly with distilled water. The collected product was exposed under microwave for
5minutes.Then the dried sample was further calcined in a tubular furnace at a temperature of 600 oC for 2
hrs. Finally greyish black product was obtained which was grinded to make fine powder (as shown in figure
2) and was kept for characterization.
Figure 1 Synthesized nanocrystalline Nickel oxide (NiO)
2.1 Characterization Of Nanoparticles
UV–visible absorption spectrum was obtained from Vis-Cary 5E model spectrometer in the wavelength
range 200 – 800 nm. FTIR spectra of nickel oxide was recorded in KBr pellets using Shimadzu (model
8400S) spectrophotometer from 4000 cm-1 to 400 cm-1. The phase and crystallinity were characterized by
using a Bruker D8 Advance Cu Kα radiation (= 1.5406A˚, Rigaku Geiger Flex X-ray
diffractometer).Surface morphology was studied by JSM-7600F scanning electron microscope. The
transmission electron micrographs were taken with a Philips CM-200-Analytical transmission electron
microscope working at 120Kv.
3. RESULTS AND DISCUSSION
The optical absorption spectrum of nickel oxide is shown in figure 2. It can be seen that the strongest
absorption peak of the as-prepared sample appears at around 280 nm, which is fairly blue shifted from the
absorption edge of bulk NiO nanoparticles. Here it is also observed that NiO nanoparticles are almost
transparent in visible region.
U
SN Abs EtOH
0.22
0.20
0.18
0.16
Abs
0.14
0.12
0.10
0.08
0.06
0.04
0.02
200
300
400
500
600
700
800
Wavelength(nm)
Figure 2 V- VIS Spectrum of Nickel oxide
Anjali Maurya et al IJSRE Volume 05 Issue 03 March 2017
Page 6282
The formation of pure nickel oxide nanoparticles after heat treatment at 600 oC was also identified by FT-IR
spectral studies. Figure 3 shows the FTIR spectra of NiO nanoparticles, which showed several significant
absorption peaks. The broad absorption band in the region of 403-472 cm−1 is assigned to Ni–O stretching
vibration mode [13-14]. The broadness of the absorption band indicates that the NiO powders are
nanocrystals. The size of samples used in this study was much less than the bulk form NiO, so that NiO
nanoparticles had its FTIR peak of Ni–O stretching vibration shifted to blue side. Due to their quantum size
effect and spherical nanostructures, the FTIR absorption of NiO nanoparticles is blue-shifted compared to
that of the bulk form. Besides the Ni–O vibration, it could be seen from Figure 3 that the broad absorption
Peaks at 3223,3408,3471,3518 cm-1 cm−1 are attributable to the band either O–H stretching vibration of
precursor impurity or moisture adsorbed on the sample. The band near 1610 cm −1 is assigned to H–O–H
bending vibration mode due to the adsorption of water in air when FTIR sample disks were prepared in open
air. These observations provided the evidence of the effect of hydration on the sample. The broad absorption
around 767cm−1 is assigned to the C=O deformation vibration. The absorption bands in the region of 1020,
1332, 1444, 1518 cm-1 are assigned to the symmetric and asymmetric stretching vibrations of carbonates.
Figure 3 IR spectrum of Nickel oxide
The purity and crystallinity of the as-synthesized NiO nanoparticles were examined by using powder X-ray
diffraction (XRD) as shown in Figure 4. It is generally agreed that the peak breadth of a specific phase of
material is directly proportional to the mean crystallite size of that material. From our XRD data, a peak
broadening of the nanoparticles is noticed. The average particle size, as determined using the Scherrer
equation, is 12 nm. The peaks positions appearing at 2θ is 37.21 o, 43.22o, 63.10o, 75.20o, and 79.39o can be
readily indexed as (101), (012), (110), (113), and (006) crystal planes of NiO, respectively. All these
diffraction peaks can be perfectly indexed to the face-centered cubic (FCC) crystalline structure of NiO, not
only in peak position, but also in their relative intensity of the characteristic peaks, which is in accordance
with that of the standard pattern JCPDS, No. 04-0835). The XRD pattern shows that the samples are single
FCC phase. The result shows that the physical phase of the NiO nanoparticles prepared in this work has
higher purity prepared in this work. The NiO lattice constant calculated from the XRD data is 4.1729A°
which is in good agreement with the reported data.
Anjali Maurya et al IJSRE Volume 05 Issue 03 March 2017
Page 6283
Nickel oxide
43.3262
12000
Intensity(a.u)
10000
37.2895
8000
62.8429
6000
75.4437
79.4584
4000
2000
10
20
30
40
50
60
70
80
90
100
2Theta
Figure 4 X- Ray Diffraction pattern of Nickel oxide
The surface morphological features of synthesized nanoparticles were studied by scanning electron
microscope. Figure 5 shows the SEM image of NiO nanoparticles. The instrumental parameters, accelerating
voltage, spot size, and magnification and working distances are indicated on SEM image. The results
indicate that mono-dispersive and highly crystalline NiO nanoparticles are obtained. The particles are mostly
irregular spherical shape. We can observe that the particles are highly agglomerated and they are essentially
cluster of nanoparticles. The observation of some larger nanoparticles may be attributed to the fact that NiO
nanoparticles have the tendency to agglomerate due to their high surface energy and high surface tension of
the ultrafine nanoparticles. The fine particle size results in a large surface area that in turn, enhances the
nanoparticles catalytic activity. So we can conclude that the prepared NiO particles are in nanometer range.
Figure 5 SEM micrograph for Nickel oxide
TEM imaging was carried out in a Philips CM-200-Analytical transmission electron microscope working at
120kV. The powder samples were supported on conventional carbon-coated film on copper grid.TEM
imaging of the powder samples is the most direct and convenient method to see and analyze the structure of
aggregates and to determine the size of particles. TEM images shown in figure 6A revealed the presence of a
large number of NiO particles with hexagonal shape and uniform size around 16.5 nm. The electron
diffraction pattern of the selected area of nanoparticles figure 6B.The appearance of strong diffraction spots
rather than diffraction rings confirmed the formation of single crystalline cubic nickel oxide.
Anjali Maurya et al IJSRE Volume 05 Issue 03 March 2017
Page 6284
Figure 6.A. TEM Images of Nickel oxide
Figure 6. B. TEM (Selected area electron diffraction pattern) of Nickel oxide
4. CONCLUSION
Nanoparticles of Nickel oxide (NiO) was synthesized by microwave assisted chemical synthesis method by
using NiCl2 and NaHCo3 precursors. FTIR spectral studies confirm the formation of pure nickel oxide
nanoparticles. Purity and crystallinity of Nickel Oxide Nanoparticles was examined by powder x-ray
diffraction. The surface Morphology of the synthesized NiO nanoparticles were studied by scanning electron
Microscopy (SEM).TEM images confirms the formation of single crystalline cubic Nickel Oxide
Nanoparticle.
REFERENCES
1. K.-S. Lee, H.-J. Koo, K.-H. Ham, W.-S. Ahn, Bull. Kor. Chem. Soc., 16 (1995) 164.
2. L. Daza, C.M. Rangel, J.Baranda, M.T. Casais, M.J. Martínez, J.A. Alonso., J. Power Sources. 86
(2000) 329-333
3. Y. Wang, J. Zhu, X. Yang, L. Lu, X. Wang., Thermo chem. Acta. 437 (2005) 106-109
4. M. Matsumiya, F. Qiu, W. Shin, N. Izu, N. Murayama, S. Kanzaki., Thin Solid Films. 419 (2002)
213
5. J. Nogues, I.K. Schuller., Exchange Bias., J. Magn. Mater. 192 (1999) 203
6. R. Cinnsealach, G. Boschloo, S.N. Rao and D. Fitzmaurice Energy Matter. Sol. Cells 57 (1999)107
Anjali Maurya et al IJSRE Volume 05 Issue 03 March 2017
Page 6285
7. A. Agrawal, H. R. Habibi, R. K. Agrawal, J. P. Cronin, D. M. Roberts, R. Caron-Popowich and C.
M. Lampert Thin Solid Films, 221(1992 ) 239
8. D. Wruck and M. Rubin J. Electrochem. Soc. 140(1993)1097
9. K. Yoshimura, Miki Tand Tanemura S Japan J. Appl. Phys. 34, (1995) 2440
10. A. Surca, B. Orel, B. Pihlar and P. Bukovec J. Electro anal. Chem. 408(1996) 83
11. Mirosław Zawadzki, J. Allo. Com. 45 (2008) 297.
12. T. Krishnakumar, R. Jayaprakash, N. Pinna, V.N. Singh, B.R. Mehta and A.R. Phani, Materials
Letters, 63 (2009) 242.
13. S.I. Cordoba-Torresi, A. Hugot-Le Goff, S. Joiret, J. Electrochem. Soc. 138 (1991) 1554.
14. N.C. Das, S. Upeti, P.E. Sokol, Journal of Experimental Nanoscience, 5(2010) 180.
Anjali Maurya et al IJSRE Volume 05 Issue 03 March 2017
Page 6286