Coupling surface modification with cocatalyst deposition on BiVO4 photoanode to enhance charge transfer for efficient solar-driven water splitting

Bismuth vanadate (BiVO4) has attracted wide attention as photoanode in water-splitting photoelectrochemical (PEC) devices. However, its catalytic performance is greatly limited by the serious charge recombination on the surface states. Herein, borate modified BiVO4 plus additional CoPi cocatalyst (B-BVO/CoPi) is developed as photoanode for PEC cell via a simple soaking and electrodeposition process. Based on the electrochemistry tests and material characteristics, the borate groups [B(OH)4] -is able to effectively prevent the charge recombination, while the outer CoPi cocatalyst enhance the activity toward oxygen evolution reaction. Therefore, the designed B-BVO/CoPi photoanode could obtain a high current density of 2.67 mA cm-2 at 1.23 VRHE with an onset potential of 0.29 VRHE, much higher than pristine BiVO4 (0.78 mA cm-2, 0.52 VRHE). This work may provide a new insight for constructing multifunctional modified photoanodes for efficient solar conversion. & COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

A modified BiVO4 photoanode (B-BVO/CoPi) was developed by soaking and electrodeposition process, which effectively prevented charge recombination and enhanced the activity for oxygen evolution reaction, achieving higher current density and onset potential compared to pristine BiVO4.