Photoelectrocatalytic properties of BiVO₄ prepared with different alcohol solvents

BiVO₄ has been receiving attention for applications in photoelectrochemical devices. This paper describes the effect of different alcohol solvents (ethanol, ethylene-glycol, PEG300 and PEG 400) on the morphology, crystal growth, crystalline size, thickness, photophysical and photoelectrochemical properties of BiVO₄ photoanodes prepared from a suitable, simple and inexpensive one-step process. All samples exhibited good crystallinity with the monoclinic phase dominating and with suitable bandgap for visible light harvesting; but the morphology, thickness, and resulting photocurrents varied broadly. The unmodified BiVO₄ photoanode prepared with PEG 300, gave a particularly good photocurrent of 0.77 mA cm⁻² at 1.23 V vs RHE under illumination of 100 mW cm⁻². In this case, a higher value for the ratio between the intensities of the XRD peaks, (040)/(121), was verified, as well as smaller crystallite size. Considering the type of solvent, the BiVO₄ photoanode prepared with PEG 300 exhibited a more intense photocurrent. The optimization of the solvent employed in the synthesis of the BiVO₄ photoanode is a crucial step in the development of a photoelectrochemical device based on this material.