Suppressing Water Dissociation via Control of Intrinsic Oxygen Defects for Awakening Solar H2O‐to‐H2O2 Generation

Abstract BiVO 4 theoretically has a thermodynamic activity trend toward highly selective water oxidative H 2 O 2 formation, but it is more inclined to generate O 2 in practical. The influence of intrinsic oxygen vacancy (O vac ), especially, on surface reactivity, has never been considered as a possible activity loss mechanism in the synthetic BiVO 4 . In this work, it is theoretically and experimentally demonstrated that the intrinsic surface O vac is responsible for lower H 2 O 2 evolution activity via promoting water dissociation to form intermediate. Through an annealing process under a V 2 O 5 rich atmosphere, the surface O vac can be eliminated that awakens the photoelectrochemical (PEC) water oxidative H 2 O 2 activity in a NaHCO 3 electrolyte, which achieves an average of 58.4%, and increases by up to 4.28 times of the one annealed in air. This work offers a general understanding of catalytic activity loss and may be extended to other photo or electrocatalysts for catalytic selectivity regulation.