LAUSR

Photocatalysts are essential in photo-energy transduction systems, and their promising utilization 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 pre-designable platform for exploring novel photocatalysts. In this review, we delineate the rapid progress of two-dimensional (2D) COFs on visible photocatalytic H2 production from water. We summarize the design principles of building blocks, linkages, and reactions for constructing photocatalytic active 2D COFs with desirable electronic properties. We introduce different strategies for enhancing photocatalytic performances by extending π-conjugation, establishing donor-acceptor configuration, functionalizing layered structures, and incorporating heteroatoms or metal complexes. We detail the unique synergy between 2D COFs and various functional materials, such as inorganic/organic semiconductors, emphasizing on the structure-to-performance relationship. We further conclude with the current challenges and promising opportunities for developing COF-based photocatalysts. This article is protected by copyright. All rights reserved.