Rational Design of Covalent Organic Frameworks as Photocatalysts for Water Splitting

Abstract Photocatalytic water splitting for hydrogen production represents a crucial approach for obtaining green energy through artificial solar energy utilization, offering a sustainable method for energy generation that helps mitigate energy shortages and protect the environment. Among the numerous photocatalytic materials, covalent organic frameworks (COFs) have garnered significant attention and intensive study from researchers due to their distinctive benefits, such as porosity, pre‐design capability, and tunability at the atomic level. Significant advancements are made in the development of materials, enhancement of performance, and comprehension of mechanisms. In this review, recent advancements in COF‐based photocatalytic water splitting are spotlighted, both in half‐reactions and overall reactions, with a particular emphasis on the rational design of COF structures to regulate the materials' optical and electrical properties, as well as the fundamental processes of photocatalysis. Drawing from current research in this field, the existing challenges, and potential opportunities are also discussed for future development.