Molecular Engineering of Donor‐Acceptor Carbon Nitride Copolymers: Enhanced Carrier Dynamics Toward Efficient Photocatalytic Hydrogen Evolution

ABSTRACT Slow carrier dynamics is the primary impediment for graphitic carbon nitride (g‐C 3 N 4 ) to realize its practical application in photocatalytic hydrogen evolution. In this work, we introduced pyridine groups into g‐C 3 N 4 via Schiff base reaction, targeting a donor‐acceptor (D‐A) system among g‐C 3 N 4 to promote the dissociation and migration of photogenerated charge and hole. The D‐A system induced an internal electric field by delocalizing the π‐conjugated charge distribution. The optimized catalysts achieved an enhanced catalytic activity of 3058 µmol g −1 h −1 . The main reason for this outperformance is attributed to the improved carrier dynamics resulting from the D‐A system. In addition, multiple characterizations and DFT results indicate that the incorporation of pyridine rings could broaden the response range of visible light and selectively break hydrogen bonds to lower the barrier for charge transfer. This work confirms the structure and interaction in intramolecular framework and provides a facile way to accelerate photogenerated carriers’ migration in g‐C 3 N 4 .