Tailoring the structural design of covalent organic frameworks for enhanced photocatalytic carbon dioxide reduction: a review

Covalent organic frameworks (COFs) exhibit distinct advantages such as extensive specific surface areas, chemical versatility, and sustainability, render them superb candidates for applications in the field of photocatalytic CO₂ reduction. In recent years, numerous COFs with remarkable photocatalytic CO₂ reduction activity have been reported, and extensive studies have been conducted to understand the mechanisms underlying the enhancement of their photocatalytic activity. This review delves into three pivotal areas: COF design, post-synthetic modifications, and composite photocatalyst construction. It uniquely examines the intricate structure-performance relationship at the molecular level, emphasizing topology, donor-acceptor interactions, crystallinity, functional groups, and heteroatom doping, thereby refining the design framework for COF-based photocatalysts. Moreover, the review offers a profound mechanistic analysis of CO₂ reduction, encompassing charge transfer, reaction intermediates, and surface kinetics, providing fresh insights into the efficient development of COF-based photocatalysts.