Enhancing the Optical Absorption and Interfacial Properties of BiVO₄ with Ag₃PO₄ Nanoparticles for Efficient Water Splitting

Photoelectrochemical water splitting using semiconductor materials has emerged as a promising approach to produce hydrogen (H₂) from renewable resources such as sunlight and water. In the present study, Ag₃PO₄ nanoparticles were electrodeposited on BiVO₄ photoanodes for water splitting. A remarkable water oxidation photocurrent of 2.3 mA·cm^-2 at 1.23 V versus reversible hydrogen electrode with ∼100% Faradaic efficiency was obtained, which constitutes a notable increase compared to the pristine BiVO₄ photoanode. It is demonstrated that the enhancement of optical absorption (above-band gap absorbance) and the decrease of surface losses after the optimized deposition of Ag/Ag₃PO₄ nanoparticles are responsible for this notable performance. Remarkably, this heterostructure shows promising stability, demonstrating 25% decrease of photocurrent after 24 h continuous operation. This approach may open new avenues for technologically exploitable water oxidation photoanodes based on metal oxides.