Stable Cocatalyst‐Free BiVO<sub>4</sub> Photoanodes with Passivated Surface States for Photocorrosion Inhibition
Rui‐Ting Gao, Lei Wang
Abstract
Abstract Improving charge transport and reducing bulk/surface recombination can increase the activity and stability of BiVO 4 for water oxidation. Herein we demonstrate that the photoelectrochemical (PEC) performance of BiVO 4 can be significantly improved by potentiostatic photopolarization. The resulting cocatalyst‐free BiVO 4 photoanode exhibited a record‐high photocurrent of 4.60 mA cm −2 at 1.23 V RHE with an outstanding onset potential of 0.23 V RHE in borate buffer without a sacrificial agent under AM 1.5G illumination. The most striking characteristic was a strong “self‐healing” property of the photoanode, with photostability observed over 100 h under intermittent testing. The synergistic effects of the generated oxygen vacancies and the passivated surface states at the semiconductor–electrolyte interface as a result of potentiostatic photopolarization reduced the substantial carrier recombination and enhanced the water oxidation kinetics, further inhibiting photocorrosion.