Photovoltaic-enhanced water splitting properties of low-temperature-synthesized BiVO4 photoanode films

Abstract

The fabrication of photoelectrodes on indium tin oxide (ITO) glass at low temperatures poses a significant challenge due to the inherent instability of ITO at reduced temperatures, while the inexpensive production of high-functionality photoanode technology is a critical determinant facilitating large-scale photovoltaic conversion in water splitting. In this work, highly efficient BiVO₄ (BVO) photoanodes with different thicknesses were grown on ITO glass at a low temperature by the sol–gel spin coating method. Pure BVO photoanode, enriched with nanostructures, exhibits a current density of 2.25 mA cm⁻² (@1.23 V vs. RHE) under AM-1.5G illumination. The photovoltaic effect induces a continual oxygen evolution reaction at zero bias voltage on the photoanode, resulting in a photocurrent density of 0.04 mA cm⁻² at zero bias. This study not only evaluates the feasibility of the large-scale fabrication of a photoanode from economic considerations but also presents potential for water splitting properties of the BVO photoanode.