Photo‐Driven Quasi‐Topological Transformation Exposing Highly Active Nitrogen Cation Sites for Enhanced Photocatalytic H2O2 Production

Abstract Herein, the exposure of highly‐active nitrogen cation sites has been accomplished by photo‐driven quasi‐topological transformation of a 1,10‐phenanthroline‐5,6‐dione‐based covalent organic framework (COF), which contributes to hydrogen peroxide (H 2 O 2 ) synthesis during the 2‐electron O 2 photoreduction. The exposed nitrogen cation sites with photo‐enhanced Lewis acidity not only act as the electron‐transfer motor to adjust the inherent charge distribution, powering continuous and stable charge separation, and broadening visible‐light adsorption, but also providing a large number of active sites for O 2 adsorption. The optimal catalyst shows a high H 2 O 2 production rate of 11965 μmol g −1 h −1 under visible light irradiation and a remarkable apparent quantum yield of 12.9 % at 400 nm, better than most of the previously reported COF photocatalysts. This work provides new insights for designing photo‐switchable nitrogen cation sites as catalytic centers toward efficient solar to chemical energy conversion.