Synergistic effect of vanadium tungsten oxide nanocomposites for enhanced photocatalysis and photovoltaic performance

Tungsten oxide nanoparticles (PW NPs) and different wt% (5, 10, 15, and 20) of vanadium tungsten oxide nanocomposites (VW NCs) namely VW1, VW2, VW3 and VW4 were synthesized successfully by using hydrothermal approach. The synthesized VW NCs were characterized by X-ray diffraction, Scanning Electron Microscope, UV-visible spectroscopy and Keithley electrometer to analyze structure, morphology, optical, and electrical properties. For PWNPs and VW NCs, structural examination of the XRD pattern reveals the development of orthorhombic and monoclinic phases, respectively. The sponge-like porous morphology for VW NCs was obvious in SEM. The absorption spectrum of band gap energy decreased with increased VW concentrations. AFM pictures show rougher surfaces with more pits and troughs than PW NPs. Gradual increase in the conductivity due to the doping concentration reduces the lattice dislocations and imperfections in the prepared NCs. The current density curves were recorded to gauge the photostability of the photoanodes with different vanadium weight percentages. The results showed that VW4 NCs had the highest power conversion efficiency (PCE), which was around 5.02%, the highest short circuit current density (Jsc), which was 8.0(mA/cm2), and the highest opencircuit voltage, which was 0.8. This improved photovoltaic efficiency of VW NCs might be attributed to their ability to capture visible light, their greater dye-loading capacity, and their decreased photoelectron recombination. The methyl blue dye (MB) was successfully degraded using VW4 NCs with a rate constant of 0.0388/min. These VW NCs also exhibited better antibacterial activity in the inactivation of S. aureus than E. coli.