Structural Distortion of g‐C₃N₄ Induced by a Schiff Base Reaction for Efficient Photocatalytic H₂ Evolution

Abstract

Photocatalytic H2 evolution by water splitting is a promising approach to address the challenges of environmental pollution and energy scarcity. Graphitic carbon nitride (g‐C3N4) has emerged as a star photocatalyst because of its numerous advantages. To address the limitations of traditional g‐C3N4, namely its inadequate visible light response and rapid recombination of photogenerated carriers, we employed a schiff base reaction to synthesize ‐C=N‐ doped g‐C3N4. The introduction of ‐C=N‐ groups at the bridging nitrogen sites induced structural distortion in g‐C3N4, facilitating n‐π* electronic transitions from the lone pair electrons of nitrogen atom and extending light absorption up to 600 nm. Moreover, the presence of heterogeneous π‐conjugated electron distribution effectively traps photogenerated electrons and enhances charge carrier separation. Benefiting from its expanded spectral response range, unique electronic properties, increased specific surface area, the doped g‐C3N4 exhibited outstanding photocatalytic H2 evolution performance of 1050.13 μmol/g/h. The value was 5.9 times greater than the pristine g‐C3N4.