Enhancing photocatalytic H₂O₂ production with Au co-catalysts through electronic structure modification

Gold-based co-catalysts are a promising class of materials with potential applications in photocatalytic H₂O₂ production. However, current approaches with Au co-catalysts show limited H₂O₂ production due to intrinsically weak O₂ adsorption at the Au site. We report an approach to strengthen O₂ adsorption at Au sites, and to improve H₂O₂ production, through the formation of electron-deficient Au^δ+ sites by modifying the electronic structure. In this case, we report the synthesis of TiO₂/MoS_x-Au, following selective deposition of Au onto a MoS_x surface which is then further anchored onto TiO₂. We further show that the catalyst achieves a significantly increased H₂O₂ production rate of 30.44 mmol g^-1 h^-1 in O₂-saturated solution containing ethanol. Density functional theory calculations and X-ray photoelectron spectroscopy analysis reveal that the MoS_x mediator induces the formation of electron-deficient Au^δ+ sites thereby decreasing the antibonding-orbital occupancy of Au-O_ads and subsequently enhancing O₂ adsorption. This strategy may be useful for rationally designing the electronic structure of catalyst surfaces to facilitate artificial photosynthesis.