Unravelling the effect of oxidation/reduction sites for photocatalytic H2O2 production

Metal/semiconductor heterostructures have been widely used to drive photochemical reactions. However, understanding of the synergies between them is still limited. In this study, we discovered that under ultraviolet (UV) light, rather than visible (Vis) excitation, the redox active sites oxidize adsorbed water and reduce oxygen molecules more efficiently. In this paper, the comprehensive mechanism of Ag@TiO 2 photocatalysis of H 2 O 2 has been elucidated and confirmed their synergies in photocatalytic reactions, through in situ characterization and theoretical calculation. Our findings provide insights into the key factors that influence the difference of photoactivity in UV and Vis light, thus having important implications for the design of solar energy conversion materials as well as environmental purification materials.