Recent Advances in Donor–Acceptor Covalent Organic Frameworks for Photocatalytic H2O2 Production

Hydrogen peroxide (H2O2), as a green oxidant and an emerging energy carrier, has attracted considerable attention for its photocatalytic synthesis. Covalent organic frameworks (COFs) have emerged as ideal photocatalyst platforms owing to their structurally designable nature and tunable optoelectronic properties. In particular, the construction of donor–acceptor (D-A) structures has proven to be a key strategy for enhancing the photocatalytic H2O2 production efficiency of COFs. This review systematically summarizes the recent advances in D-A-type COFs for photocatalytic H2O2 production. We first elucidate the intrinsic mechanism by which D-A structures enhance photocatalytic performance, namely the promotion of exciton dissociation and charge separation via intramolecular charge transfer effects. Subsequently, we provide a comprehensive assessment of strategies for optimizing the photocatalytic performance of D-A COFs, including D-A architecture design (encompassing D-A, D-π-A, A-D-A variants, and others), linkage engineering, functional group modification, dimensionality and topology modulation, and heterojunction construction. Finally, we critically analyze the current shortcomings in stability, mechanistic understanding, scalable synthesis, and practical applications, and offer perspectives on future research directions. This review aims to provide a systematic reference for the rational design of high-performance D-A-type COF photocatalysts.