A Theoretical Perspective on Charge Separation and Transfer in Metal Oxide Photocatalysts for Water Splitting

Abstract Semiconductor‐based photocatalytic decomposition of water is one of the most promising techniques to produce clean and renewable energy in the future. Photogenerated charge separation and transfer is considered as one of the crucial steps controlling the conversion efficiency of solar energy in heterogeneous photocatalysis. Many experimental methods have been developed to enhance the efficiency of this process, such as fabricating junction structures, manipulating exposed facets, and loading suitable cocatalysts. Besides a variety of time and spatial resolved spectroscopic techniques, density functional theory calculations have been widely used to explore the photoinduced charge dynamics due to the advances of relevant theory and methodologies along with the improved computer performance. This article reviews recent theoretical researches mainly by means of density functional theory calculations in the charge separation and transportation in metal oxide photocatalytic systems . We introduce some common theoretical and computational methods for investigating physicochemical properties of photocatalytic materials, discuss the charge mobility in bulk and surface of semiconductors, the interfacial charge transfer in junction structures, and the role of cocatalysts in complex photocatalysts, and then evaluate potential research directions for superior photocatalytic systems on the basis of computational investigation and theoretical comprehension of intrinsic properties.