Unraveling Mechanisms and Engineering Strategies for Superior Photocarrier Dynamics Toward Efficient Photocatalysis

Photocatalysis offers a promising solution to environmental and renewable energy issues. However, the efficiency of photocatalysis depends critically on the efficient bulk and surface separation of photoexcited charge carriers, which largely hinders its development for practical applications. Developing effective photocatalysts in photocatalytic systems is pivotal to achieving high efficiency. In recent years, many methods have emerged to improve the separation and transmission efficiency of photogenerated carriers on the surface, in the bulk, and at the interface of photocatalysts, which remain to be fully examined and are the focus of this article. Following this introduction, section 2 concisely introduces the kinetics and mechanisms of charge carrier separation and transport. Then, the characterization methods of carrier separation and transport are reviewed. The following section describes in detail the strategies to enhance bulk carrier separation and transport, including spontaneous polarization, the application of external driving force, and the introduction of internal driving forces. Furthermore, strategies to accelerate the separation and transport of photogenerated charge carriers on surfaces and interfaces are systematically outlined in the following sections. The last section summarizes the main challenges and some exciting prospects for future research on the separation and transport of photogenerated charge carriers in photocatalysts, which are considered to play a pivotal role in promoting the development of this important research field.