Donor–Acceptor Modification of Carbon Nitride for Enhanced Photocatalytic Hydrogen Evolution

Abstract The construction of conjugated copolymers with a donor–acceptor (D–A) system has emerged as a promising strategy for improving photocatalytic activity. Herein, a donor–acceptor modified carbon nitride (CN) conjugated copolymer is fabricated via facile thermal copolymerization of 2‐aminobenzimidazole (abIM) and urea. The experimental results demonstrate that the abIM units are successfully incorporated into the framework of CN and the main chemical structure of CN is still preserved. These abIM units can serve as electron acceptors, extending the π‐conjugated system and inducing the intramolecular charge transfer via an internal electric field. As a result, the construction of D–A structure not only improves the optical utilization efficiency but also facilitates the intramolecular migration of electrons and holes, leading to enhanced photocatalytic hydrogen evolution (2566 µmol g⁻¹ h⁻¹) as compared to pristine CN. This work provides a simple but effective method for preparing high‐performance carbon nitride photocatalysts.