Effect of Solvent on the Photoelectrochemical Performance of WO3 Nanostructures for Hydrogen Evolution

Hydrogen has emerged as a pivotal energy carrier for a sustainable future, and photoelectrocatalytic (PEC) water splitting presents a promising method for its production using semiconductor materials. Tungsten trioxide (WO3) is a potential photoanode for PEC water splitting, but its performance is often hindered by poor charge separation, material stability, and low efficiency. This study investigates the effect of solvent additives during the synthesis of WO3 nanostructures via anodization, focusing on isopropanol and formamide. The impact of these solvents on the morphology and photoelectrochemical properties of the resulting WO3 films was analyzed. Results indicate that water is the optimal solvent for synthesizing WO3 nanostructures, yielding the highest photocurrent density (0.629 mA/cm²) and theoretical hydrogen production of 2.87 L H2/h·m², significantly outperforming samples synthesized with isopropanol and formamide. The introduction of isopropanol and formamide significantly reduced the performance due to morphological and structural changes that hinder charge transport. Although hydrogen evolution was not directly measured, the enhanced photocurrent suggests improved potential for solar water splitting applications. These findings provide insights into optimizing WO3-based photoanodes for enhanced hydrogen production, contributing to sustainable energy solutions.