Constructing photocatalytically active and stable covalent organic frameworks containing both oxidative and reductive reaction centers remain a challenge. In this study, benzotrithiophene-based covalent organic frameworks with spatially separated redox centers are rationally designed for the photocatalytic production of hydrogen peroxide from water and oxygen without sacrificial agents. The triazine-containing framework demonstrates high selectivity for H₂O₂photogeneration, with a yield rate of 2111 μM h⁻¹(21.11 μmol h⁻¹and 1407 μmol g⁻¹h⁻¹) and a solar-to-chemical conversion efficiency of 0.296%. Codirectional charge transfer and large energetic differences between linkages and linkers are verified in the double donor-acceptor structures of periodic frameworks. The active sites are mainly concentrated on the electron-acceptor fragments near the imine bond, which regulate the electron distribution of adjacent carbon atoms to optimally reduce the Gibbs free energy of O₂* and OOH* intermediates during the formation of H₂O₂.

This review analyzes advanced catalysts and C ₂₊ synthesis mechanisms based on theoretical explorations and in situ / operando characterizations. Triphasic interface optimization is discussed for the potential of industry-compatible stability.

Hierarchical Co₃O₄@CdIn₂S₄ p–n heterojunction photocatalysts have been constructed by an in situ surface growth method for CO₂ reduction with visible light.

All-solid-state direct NiTiO ₃ /Cd _0.5 Zn _0.5 S Z-scheme heterostructures enabled the visible-light hydrogen evolution at an optimal H ₂ -releasing rate of 26.45 mmol h ⁻¹ g ⁻¹ .