Theoretical calculation of a TiO2-based photocatalyst in the field of water splitting: A review

Abstract Currently, energy and environmental problems are becoming more serious. The use of solar energy to split water and produce clean, renewable hydrogen as an energy source is a feasible and effective approach to solve these problems. As the most promising semiconductor material for photocatalytic water splitting, TiO 2 -based nanomaterials have received increasing attention from researchers in academia and industry in recent years. This review describes the research progress in the theoretical calculations of TiO 2 -based photocatalysts in water splitting. First, it briefly introduces some commonly used theoretical calculation methods, the crystal structure of TiO 2 and its photocatalytic mechanism, and the principle of doping and heterojunction modification to improve the photocatalytic performance of TiO 2 . Subsequently, the adsorption state of water molecules with different coverages on the surface of TiO 2 , the rate-limiting steps of the splitting of water molecules on the surface of TiO 2 , and the transfer process of photogenerated current carriers at the interface between water molecules and TiO 2 are analyzed. In addition, a brief review of research into the theoretical calculations of TiO 2 -based commercial photocatalysts in the field of water splitting is also provided. Finally, the calculation of TiO 2 -based photocatalytic water-splitting simulations is summarized, and possible future research and development directions are discussed.