RESULTS AND DISCUSSION
Ammonium heptamolybdate/ammonium molybdate (AHM) is a big complex molecule.
The chemical structure of AHM is shown below
Fig. 1 Chemical structure of Ammonium molybdate
Primarily, the NH4+ and OH- groups are removed from AHM structure by the hydrolysis
reaction in water [12]. The CMC used in this experiment, play a vital role in inducing the
MoO3 nuclei and directing the crystal growth [12]. The functional groups of CMC reacts with
Mo+6 in the centre of the complex and strongly interacts with it [12]. Hence, Mo ions are
separated from the complex compound by dispersion. Later, additive molecules are removed
by calcination at high temperature resulted in formation of MoO3 nanoparticle. Fig. 2 shows
the X-Ray Diffraction pattern of the synthesized MoO3 nanoparticles. The synthesized MoO3
produces large number of peaks due to the formation of polycrystalline MoO3 nanoparticles.
The peaks were compared with JCPDS standard, it was well matched. The peaks at 12 and 25
reveal that they are in orthorhombic structure. The crystalline size was calculated using
Scherer formulae and it gave the synthesized MoO3 particles are in the size of nanometre
range. The average size of the MoO3 nanoparticles were found to be 132nm.
(040)
4000
3500
2500
(060)
(020)
2000
(110)
1500
(130)
Intensity (a.u.)
3000
1000
500
0
10
20
30
40
50
60
70
2 (degree)
Fig. 2 XRD Analysis pattern of synthesized MoO3 nanoparticles which shows
orthorhombic phase.
Fig. 3 represents the FTIR spectra of the synthesized MoO3. The main peaks was found in
the absorption regions at 582.32cm-1 and 992.10 cm-1 which shows the formation of MoO3.
The band at 992 cm-1 is characteristic of the vibration of the Mo=O terminal bond. The
dominant band at 872 cm-1is associated with the vibration of Mo-O-Mo bridging bonds. The
decrease in intensity of the band at 582.32 cm-1 may be considered as a result of the
decreasing number of edge shared bonds. The frequency stretch at 3770cm-1 indicates
stretching of O-H which shows absorption of water. The peak at 2393cm-1 indicates very
weak C (Carbon) bond formation. The peak at 1622cm-1 represents the symmetry of COObond. The peaks at 2393 cm-1 and 1622 cm-1 represents the formation of MoO3 through CMC.
Fig. 3 FTIR analysis graph of Synthesised MoO3 Nanoparticles
Fig. 4 (a)
Fig. 4 (b)
Fig. 4 SEM images of synthesized MoO3 nanoparticles
Fig. 4. SEM images of synthesized MoO3 nanoparticle shows flake and rod shapes
Fig. 4 (a,b,c) shows the morphology of molybdenum trioxide nanoparticles has been
characterized by scanning electron microscopy (SEM). Observed images were show the rod
and flake like nanoparticle formation. The SEM images show the Nanoparticle were in the
range 100 to 250 nm.