Enhancing Mass Transport and Charge Transfer in Carbon Nitride Photocatalysts for Efficient Benzylamine Oxidation Coupled With Hydrogen Evolution

Polymeric carbon nitride is a promising photocatalyst for coupling benzylamine (BA) oxidation with hydrogen evolution. However, its efficiency is often limited by a low specific surface area, high defect density, inefficient charge separation, and poor mass transport. To address these challenges, we developed a hybrid template‐molten salt strategy to synthesize crystalline mesoporous carbon nitride nanospheres (C‐MCNs). The resulting C‐MCNs architecture not only enhances mass transport but also reduces charge transfer losses, outperforming crystalline bulk carbon nitride (C‐BCN) in mass transfer capability and exhibiting lower charge loss than amorphous mesoporous carbon nitride nanospheres (A‐MCNs). The optimized C‐MCNs exhibit exceptional photocatalytic performance, achieving N ‐benzylidenebenzylamine (NBI) production from BA with high selectivity (>99%) at a rate of 15.6 mmol g −1 h −1 , alongside H 2 generation at 15.9 mmol g −1 h −1 . The hydrogen evolution rate with C‐MCNs is 3.6 times and 8.2 times higher than that of C‐BCN and A‐MCNs, respectively. This work opens a pathway for the rational design of high‐performance photocatalysts by introducing a hybrid template‐molten salt strategy that enables synergistic control over crystallinity and nanostructure in carbon nitride.