Sacrificial‐Agent‐Triggered Mass Transfer Gating in Covalent Organic Framework for Hydrogen Peroxide Photocatalysis

Abstract Covalent organic framework (COF) photocatalysts for H 2 O 2 production remain challenging by mass transport limitations and poor charge separation efficiency. Herein, a sacrificial agent‐triggered mass‐transfer gating (MTG) strategy is developed to reconfigure interfacial reaction for photocatalytic H 2 O 2 generation via synthesized benzothiazole‐COFs. This enables precise switching of the dominant photocatalytic mechanism between surface‐confined directional charge transfer pathways and diffusion‐dominated redox processes. Notably, benzyl alcohol (BA) enhances the mass transport and the catalytic site accessibility, scavenges photogenerated holes, and supplies protons for coupling reactions, thereby increasing the H 2 O 2 yield of Tp‐BTz COF to 100.9 mmol g −1 h −1 and achieving the outstanding photocatalytic performance reported to date. Both Tp‐BTz COF and Tp‐TTz COF demonstrate durably high H 2 O 2 production efficiency even in the high‐salinity seawater and municipal tap water systems. The generated H 2 O 2 effectively degrades organic pollutants such as methyl orange (MO) and rhodamine B (RhB), demonstrating practical potential for wastewater treatment. The proposed gating strategy by introducing BA enables three synergistic functions: i) modulating interfacial reactions, ii) acting as a sacrificial agent to scavenge holes, and iii) supplying abundant protons (H + ) for the oxygen reduction reaction (ORR) to facilitate the proton‐coupled electron transfer. This approach establishes a generalizable paradigm for designing high‐performance photocatalytic systems toward sustainable energy and environmental applications.