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

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