Photocatalysts are essential in photoenergy transduction systems, and their promising use for photocatalytic hydrogen evolution from water has been intensively studied for decades. Covalent organic frameworks (COFs) are emerging crystalline materials that are featured with highly ordered skeletons with intrinsic uniform pores, conferring a predesignable platform for exploring novel photocatalysts. In this review, the rapid progress of two-dimensional (2D) COFs on visible photocatalytic H₂ production from water is delineated. This review summarizes the design principles of building blocks, linkages, and reactions for constructing photocatalytic active 2D COFs with desirable electronic properties. This review introduces different strategies for enhancing photocatalytic performances by extending π-conjugation, establishing donor–acceptor (D–A) configuration, functionalizing layered structures, and incorporating heteroatoms, or metal complexes. This review details the unique synergy between 2D COFs and various functional materials, such as inorganic–organic semiconductors, emphasizing on the structure-to-performance relationship. This review further concludes with the current challenges and promising opportunities for developing COF-based photocatalysts.

中文翻译：

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用于光催化析氢的共价有机框架：设计、策略和结构与性能的关系

光催化剂在光能转换系统中是必不可少的，几十年来，人们对它们在光催化从水中析出氢方面的前景进行了深入研究。共价有机框架 (COF) 是新兴的晶体材料，具有高度有序的骨架和固有的均匀孔隙，为探索新型光催化剂提供了一个可预先设计的平台。在这篇综述中，描述了二维 (2D) COF 在可见光催化水中生产H _{2方面的快速进展。}本综述总结了用于构建具有理想电子特性的光催化活性二维 COF 的构件、连接和反应的设计原则。本综述介绍了通过扩展π来增强光催化性能的不同策略-共轭、建立供体-受体 (D-A) 配置、功能化层状结构以及掺入杂原子或金属配合物。这篇综述详细介绍了二维 COF 与各种功能材料（如无机-有机半导体）之间的独特协同作用，强调了结构与性能的关系。这篇综述进一步总结了当前开发基于 COF 的光催化剂的挑战和有希望的机会。