Abstract:
A facile reflux method was used to synthesise undoped and Au-doped V2O5
nanoparticles powder samples at concentrations ranging from 1 wt% to 5 wt%. The
prepared samples’ structural and optical properties were examined using x-ray
diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray
spectroscopy (EDS),Brunuaer-Emmett-Teller (BET),ultraviolet-visible spectroscopy
(UV-Vis) and Fourier transform infrared spectroscopy (FT-IR). The XRD
diffractograms confirmed that the prepared samples have an orthorhombic crystal
structure. The lattice parameters of undoped and Au-doped V2O5 samples were
determined and found to match with those of bulk V2O5. The average crystallite size
of the undoped and Au-doped V2O5 was found to increase at low Au concentrations
(1 wt% - 3 wt%) and decrease at high Au concentrations (4 wt% - 5 wt%) due to an
increased number of nucleation sites. The SEM images showed morphological
changes from spherical to nanorods for undoped and doped V2O5 respectively. The
elemental composition of the undoped and Au-doped V2O5 nanoparticles were
confirmed using EDS. The same was done for the 2 wt% Au-doped V2O5 sample
that was contaminated by mercury (Hg). BET was used to probe the surface area
of the undoped and Au-doped V2O5 while also confirming that all the samples were
mesoporous. The band gap of the undoped and Au-doped V2O5 samples were
determined from the UV-Vis absorption spectra and found to increase at high Au
concentrations. The functional groups present in all prepared samples were
investigated using FTIR spectroscopy.
