A facile one-step strategy for in-situ fabrication of WO₃-BiVO₄ nanoarrays for solar-driven photoelectrochemical water splitting applications

This paper presents a facile single step strategy for fabrication of tungsten, bismuth and vanadium mixed metal oxide nanoarrays. WO₃-BiVO₄heteronanostructure was obtained hydrothermally with reaction time of two hrs at low temperature 110 °C. The morphology of as prepared WO₃-BiVO₄heterostructure revealed uniform and prominent nanorods like architectures under FE-SEM. These heteronanostructures were of variable sizes i.e., width ⩽100 nm and length 200–400 nm respectively. The energy dispersive X-ray analysis (EDX) and elemental mapping of heteronanostructure further confirmed W, Bi, V and O entities in good elemental composition. The purity and crystalline nature of as synthesized WO₃-BiVO₄were confirmed from X-ray crystallographic (XRD) analysis. UV–Visible spectroscopy and Raman analysis were also carried out to investigate optical properties of WO₃-BiVO₄. The band gap energy of WO₃-BiVO₄calculated from UV–Visible absorption and diffused reflectance spectroscopy's was observed to be 2.1 eV respectively. The photoelectrochemical (PEC) studies of FTO coated WO₃-BiVO₄showed a stable and repeatable photocurrent response under 1 SUN solar irradiation source. The linear sweep voltammetry (LSV) and Cyclic Voltammetry (CV) also corroborated substantial photocurrents at different oxidation and reduction potentials. Consequently, it is envisioned that this one-step strategy for in-situ fabrication of WO₃-BiVO₄heteronanostructures have potential applications in solar-driven photoelectrochemical water splitting reactions.