Atomic‐Level Charge Separation Strategies in Semiconductor‐Based Photocatalysts

Semiconductor‐based photocatalysis as a productive technology furnishes a prospective solution to environmental and renewable energy issues, but its efficiency greatly relies on the effective bulk and surface separation of photoexcited charge carriers. Exploitation of atomic‐level strategies allows in‐depth understanding on the related mechanisms and enables bottom‐up precise design of photocatalysts, significantly enhancing photocatalytic activity. Herein, the advances on atomic‐level charge separation strategies toward developing robust photocatalysts are highlighted, elucidating the fundamentals of charge separation and transfer processes and advanced probing techniques. The atomic‐level bulk charge separation strategies, embodied by regulation of charge movement pathway and migration dynamic, boil down to shortening the charge diffusion distance to the atomic‐scale, establishing atomic‐level charge transfer channels, and enhancing the charge separation driving force. Meanwhile, regulating the in‐plane surface structure and spatial surface structure are summarized as atomic‐level surface charge separation strategies. Moreover, collaborative strategies for simultaneous manipulation of bulk and surface photocharges are also introduced. Finally, the existing challenges and future prospects for fabrication of state‐of‐the‐art photocatalysts are discussed on the basis of a thorough comprehension of atomic‐level charge separation strategies. Semiconductor photocatalytic efficiency greatly relies on effective charge separation. The recent progress of atomic‐level strategies for promoting charge separation and migration in the bulk, on the surface, and both bulk and surface of a photocatalyst are highlighted and a guideline for the bottom‐up design of high‐performance photocatalysts suggested.