An Oxazine-Locked Covalent Organic Framework by a Tandem Pinner/Schiff Base Reaction for Hydrogen Peroxide Photosynthesis

Linkage design is a decisive factor in determining the stability and function of covalent organic frameworks (COFs). Herein, we report oxazine-locked two-dimensional COFs constructed via an irreversible cascade reaction integrating consecutive Pinner and Schiff base reactions. This design couples framework crystallization with permanent linkage formation, yielding COFs with high chemical robustness under acidic and basic conditions. These frameworks act as efficient photocatalysts for H 2 O 2 generation, illustrating a general synthetic route for stable COF-based photocatalysts in artificial photosynthesis.