A thioether-decorated triazine-based covalent organic framework towards overall H2O2 photosynthesis without sacrificial agents

Covalent organic frameworks (COFs) have been rapidly applied in photocatalytic H2O2 production owing to their strong light absorption, suitable band structure, etc. However, sluggish water oxidation reaction (WOR) with low selectivity restricts the H2O2 photosynthesis efficiency of COFs. Herein, a thioether-decorated triazine-based COF (TDB-COF) was designed and developed for efficient overall H2O2 photosynthesis. TDB-COF achieves a photocatalytic H2O2 production rate of 723.5 μmol g−1 h−1 without any sacrificial agents and exhibits remarkable cyclic stability. The modification of thioether groups broadens the visible light absorption of TDB-COF and narrows its optical band gap. Such a strategy can not only effectively regulate the band structure suitable for two-electron two-steps WOR but also promote the photogenerated carriers transfer and accelerate a two-electron two-steps oxygen reduction process to generate H2O2, thus ultimately boosting the overall H2O2 photosynthesis. This work provides valuable suggestions for the development of the functional COFs towards overall H2O2 photosynthesis.