An Improved Metal-to-Ligand Charge Transfer Mechanism for Photocatalytic Hydrogen Evolution.

It is of great significance to fabricate a full-spectrum-active photocatalysts for more efficient utilization of solar energy. An improved metal-to-ligand charge transfer (MLCT) mechanism is proposed for a photocatalyst based on graphitic carbon nitride (g-C3 N4 ). UV/Vis spectroscopy indicates that the as-prepared photocatalyst absorbs light at λ<1100 nm. The rather stable photocatalyst is found to be 26.1 times more active in photocatalytic hydrogen evolution (868.9 μmol h-1  g-1 ) than bulk g-C3 N4 (B-CN) under visible light. The material exhibits high activity under near-infrared (NIR) irradiation (49.1 μmol h-1  g-1 ). The mechanism of photocatalytic activity and stability are investigated by both experiment and theory. This proposed mechanism may have great potential for engineering renewable photocatalysts in the future.