Dynamic covalent organic framework linkages unlock efficient H ₂ O ₂ photosynthesis

Photocatalytic synthesis of H2O2 from H2O and O2 using solar energy has attracted increasing attention as a sustainable alternative to the industrial anthraquinone process, which suffers from safety concerns, a high energy consumption, and the use of organic solvents. 1, 2Although semiconductor photocatalysts have been extensively studied [3][4][5] , achieving efficient H2O2 production remains challenging due to insufficient visible-light utilization and rapid recombination of photogenerated charge carriers.Among emerging photocatalysts, covalent organic frameworks (COFs) have recently gained considerable interest because their ordered structures, tunable building blocks, and extended -conjugation provide unique opportunities to engineer photocatalytic properties. 6,7 evertheless, many COF-based systems still suffer from a poor charge separation efficiency, motivating the development of new COF architectures capable of facilitating directional charge transport while being catalytically active and selective.Azole-linked COFs have recently emerged as a promising class of materials for photocatalytic H2O2 production owing to their superior chemical stability and the strong electron affinity of the azole rings. 8These rings have been proposed to serve as electron-accepting sites for oxygen activation.However, a practical limitation lies in their synthetic complexity.In contrast to imine-, vinyl-, or azine-linked COFs, which can be obtained in a one-step synthesis, azole-linked frameworks typically require post-synthetic oxidation or cyclization of preformed imine COFs. 9-11Such multistep transformations inevitably increase synthetic complexity, limit scalability, and restrict the structural diversity of azole-linked COFs.Consequently, the development of J u s t A c c e p t e dCarbon Future (1-x)Carbon Future, 2026, 3, 9200073strategies that facilitate the direct or in-situ formation of azole linkages during catalytic operation would signify a substantial advancement in the field of highperformance COF photocatalysts.