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

Developing efficient heterostructured photo-catalysts 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.