Constructing built-in electric field in graphitic carbon nitride hollow nanospheres by co-doping and modified in-situ Ni2P for broad spectrum photocatalytic activity

Abstract The construction of built-in electric field is generally considered as an effective strategy to enhance photocatalytic performance due to its significant role in charge separation. Herein, a built-in electric field within g-C3N4 hollow nanospheres co-doped with sulfur and oxygen and modified in-situ Ni2P is proposed. Ni2P/SO HC3N4 exhibits significantly enhanced board spectrum photocatalytic properties for hydrogen precipitation (5.21 mmol h−1 g−1) and photocatalytic Cr(VI) reduction without the use of noble metal. It also achieves high photocatalytic sterilization activity and remarkable stability when used to completely inactivate E. coli (107) in 60 min under Vis-NIR light irradiation. The enhanced performance is attributed to the formation of a curved hollow sphere structure, which promotes the electron transfer between the inner and outer layers. In addition, co-doping inhibits the recombination of photogenerated carriers, and the built-in electric field recombined with Ni2P facilitates the electron transfer between the composite interfaces. This design strategy demonstrates an original method of devising multifunctional photocatalysts with enhanced activity and stability.