Transition of Schottky to Ohmic Contact via P Doping Promotes Efficient H2 Evolution of g-C3N4

Utilizing photocatalysis to split water is a highly prospective technique for H-2 evolution. However, carrier recombination in photocatalysts results in poor photocatalytic H-2 evolution performance. The introduction of metallic substances as cocatalysts has found extensive application in enhancing photocatalytic performance. However, the existence of Schottky barriers remains a hindrance to the separation of photogenerated carriers. In this work, the electronic structure of g-C3N4 was modulated and optimized by P doping, changing the contact mode from the Schottky contact to the Ohmic contact, greatly promoting photogenerated charge separation and transfer. Under xenon lamp illumination, the H-2 production rate of the prepared Ohmic contact photocatalyst is nearly 5 times that of the original Schottky contact one. This work gives new insights into the rational design of an efficient water-splitting photocatalyst.