Novel Cu₃P/g-C₃N₄ p-n heterojunction photocatalysts for solar hydrogen generation

Developing efficient heterostructured photocatalysts to accelerate charge separation and transfer is crucial to improving photocatalytic hydrogen generation using solar energy. Herein, we report for the first time that p-type copper phosphide (Cu₃P) coupled with n-type graphitic carbon nitride (g-C₃N₄) forms a p-n junction to accelerate charge separation and transfer for enhanced photocatalytic activity. The optimized Cu₃P/g-C₃N₄ p-n heterojunction photocatalyst exhibits 95 times higher activity than bare g-C₃N₄, with an apparent quantum efficiency of 2.6% at 420 nm. A detail analysis of the reaction mechanism by photoluminescence, surface photovoltaics and electrochemical measurements revealed that the improved photocatalytic activity can be ascribed to efficient separation of photo-induced charge carriers. This work demonstrates that p-n junction structure is a useful strategy for developing efficient heterostructured photocatalysts.