Facile Construction of Fully Conjugated Benzotristhiazole‐Based Covalent Organic Frameworks for Efficient Photocatalytic H ₂ O ₂ Production

Abstract Vinylene‐linked covalent organic frameworks (COFs) have garnered significant attention owing to their extensive π‐electron delocalization and inherent stability. However, the synthesis difficulty and lack of functional monomers available for Aldol reaction greatly restrict the structural diversity and application. Herein, a novel benzotristhiazole‐based monomer (BTZ) featuring a rigid and π‐conjugated structure is synthesized. Using this monomer, three highly crystalline vinylene‐linked COFs are successfully synthesized via a trace solvent‐assisted synthesis strategy. Benefiting from the stable and N, S‐codoped conjugated structures, these COFs exhibited excellent photocatalytic performance for H ₂ O ₂ generation. The incorporation of triazine units is found to significantly improve photocatalytic activity, with the styryl‐substituted triazine unit demonstrating superior efficiency in promoting H ₂ O ₂ production compared to the phenyl‐substituted counterpart. Notably, BTZ‐3 exhibit a hydrogen peroxide generation rate of 3267 µmol h ⁻¹ g ⁻¹ when benzyl alcohol (BA) is employed as a sacrificial agent. This research provides a new functional monomer and synthetic strategy and will facilitate the structural diversities and photocatalytic applications of vinylene‐linked COFs.