Synergy of Ag and Interfacial Oxygen Vacancies on TiO for Highly Efficient Photocatalytic Production of HO.

Photocatalytic HO production stands as a promising sustainable technology for chemical synthesis. However, rapid charge recombination and limited oxygen adsorption by photocatalysts often limit its efficiency. Herein, we demonstrate that the synergy of Ag and interfacial oxygen vacancies on TiO could overcome these challenges. The optimized Ag/TiO-50 photocatalyst achieved an impressive HO production rate of 12.9 mmol h g and maintained a steady-state concentration of 12.8 mM, significantly outperforming most TiO-based photocatalysts documented in the literature. Detailed mechanistic studies, aided by TAS, X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR) techniques, indicate that the oxygen vacancies at the Ag-TiO interface act as an interfacial hole trap, inducing a directional hole transfer. This, coupled with Ag acting as an electron acceptor, synergistically boosts the electron-hole separation. Additionally, the increased amount of oxygen vacancies at the Ag-TiO interface of Ag/TiO-50 leads to enhanced O adsorption, thus contributing to its superior catalytic performance. This study provides valuable insights into interfacial traps in the charge transfer process and highlights the potential of interface regulation for achieving efficient photocatalytic conversion.