Current status of PDI-based heterojunction photocatalytic system for energy production and environmental remediation applications.

Photocatalysis has shown great potential in solving environmental and energy problems. Perylene diimide (PDI) has received significant attention as a semiconductor photocatalyst. However, pure PDI photocatalysts still face challenges because of their low photogenerated carrier separation efficiency, leading to suboptimal photocatalytic activity. In recent years, PDI-based heterostructures have become a hot research topic because of their greatly improved carrier separation efficiency and photocatalytic performance. According to the different transfer mechanisms of photogenerated carriers between PDI and coupling components, PDI-based heterostructured photocatalysts can be classified into conventional type-II, Z-scheme, and S-scheme heterojunctions. This paper reviews the recent research progress in the design of PDI-based heterojunction photocatalysts and their photogenerated carrier transfer mechanisms. Subsequently, the enhanced photocatalytic activity of PDI-based heterojunctions with respect to environmental remediation and energy conversion in terms of pollutant degradation, CO 2 reduction, and photocatalytic H 2 evolution have been thoroughly reviewed. Moreover, the typical mechanism of the photocatalytic reaction of PDI-based composites is described in detail. Lastly, the unresolved challenges and potential applications of PDI-based heterojunction photocatalysts are presented to guide the future development direction. [Display omitted] • The charge transfer mechanism and design of PDI-based heterojunction are deeply discussed. • Various methods for the preparation of PDI-based heterojunction photocatalysts are presented. • The applications of PDI-based heterojunction photocatalysts in energy production and environmental remediation are reviewed. • Prospects and challenges for the development of PDI-based photocatalytic systems are pointed. [ABSTRACT FROM AUTHOR]