Abstract
Gold-based co-catalysts are a promising class of materials with potential applications in photocatalytic H(2)O(2) production. However, current approaches with Au co-catalysts show limited H(2)O(2) production due to intrinsically weak O(2) adsorption at the Au site. We report an approach to strengthen O(2) adsorption at Au sites, and to improve H(2)O(2) production, through the formation of electron-deficient Au(δ+) sites by modifying the electronic structure. In this case, we report the synthesis of TiO(2)/MoS(x)-Au, following selective deposition of Au onto a MoS(x) surface which is then further anchored onto TiO(2). We further show that the catalyst achieves a significantly increased H(2)O(2) production rate of 30.44 mmol g(-1) h(-1) in O(2)-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 O(2) adsorption. This strategy may be useful for rationally designing the electronic structure of catalyst surfaces to facilitate artificial photosynthesis.