Mildly regulated intrinsic faradaic layer at the oxide/water interface for improved photoelectrochemical performance

as model materials, we propose a mild heat treatment to increase the hydroxyl concentration in the hydrated surface layers of the oxides, which improves their photoelectrochemical performance remarkably. Moreover, we find that the heat-regulated hydrated layer plays the role of a hole transfer mediator between oxides and the electrolyte, which can accelerate both interface charge collection and oxygen evolution reaction kinetics in acidic solution. The new insights into the intrinsic hydrated interface layer on oxides can offer guidance not only in photoelectrocatalysis, but also in the other applications mentioned above.