Oxygen vacancies activating surface reactivity to favor charge separation and transfer in nanoporous BiVO4 photoanodes

The sluggish catalytic reactivity on the surface of most semiconductors is a common obstacle in developing photo-electrochemical (PEC) electrodes. Loading cocatalysts becomes a plausible scenario but remains chal-lenging in the integration with semiconductors due to the complicated interfacial issues. This work introduces an feasible strategy of activating surface reactivity, alternative to cocatalysis, in cooperating with semiconductor photoactivity to boost PEC performance. We apply an ionized argon plasma technology on three-dimensional (3D) nanoporous BiVO4 (BVO) to controllably generate surface oxygen vacancies, which enable surface activation favoring charge separation and transfer towards water oxidation reaction (WOR). A remarkable photo current density of 4.32 mA cm(-2) is achieved at 1.23 V versus reversible hydrogen electrode (RHE) under AM 1.5 G illumination, which is a record among the reported single BVO photoanodes and even surpasses the performances of most cocatalyst-assisted ones. This study provides an alternative solution to sluggish catalytic kinetics on semiconductor photoelectrodes, thus paving a novel avenue to modulate cooperation with photo activity in PEC technology.

Automated summary

This study introduces a feasible strategy of activating surface reactivity on semiconductors to enhance PEC performance by cooperatively working with semiconductor photoactivity. By using ionized argon plasma technology on 3D nanoporous BiVO4, surface oxygen vacancies are controllably generated to improve charge separation and transfer efficiency, resulting in a significant increase in photo current density.