Rationally designed Bi@BiOCl/g-C3N4 heterostructure with exceptional solar-driven photocatalytic activity

Abstract

Bi@BiOCl/g-C3N4 was prepared via a solvothermal method followed by a surface oxidation treatment. In this hybrid structure, Bi spheres were deposited on p-g-C3N4, and BiOCl was coated on the surface of Bi spheres except for the interfaces between g-C3N4 and metallic Bi. A series of characterization techniques proved its successful preparation. It exhibited high photocatalytic activities in RhB and 2,4-DCP degradation and Cr(VI) reduction under simulated solar light illumination. Besides, it exhibited efficient photo-mineralization of 2,4-DCP. Its efficient photocatalysis was attributed to its high separation efficiency of charge carriers and high redox potential of its photo-generated electrons and holes, which resulted from the Z-scheme photo-induced charges transfer in Bi@BiOCl/g-C3N4. Besides, the metallic Bi was served as Z-scheme bridge in Bi@BiOCl/g-C3N4, which would accelerate the Z-scheme photo-induced charges transfer. Meanwhile, its core–shell structure led to high stability during photocatalysis. Afterwards, its photocatalytic mechanisms for organic pollutants degradation and Cr(VI) reduction were illustrated. The Z-scheme core–shell structured photocatalyst in our work is a promising candidate for the degradation of organic pollutants and reduction of heavy metal ions.