Synthesis and Characterization of Z-Scheme Heterojunction CoWO4/RGO/g-C₃N₄ as a Visible Light-Driven Photocatalyst for Novel Removal of Organic Pollutant

In this study, novel Z-scheme heterojunction photocatalyst CoWO4/RGO/g-C3N4 was successfully fabricated by a facial hydrothermal. Obtained morphology and topography studies indicated that deposition of reduced graphene oxide (RGO) and CoWO4 nanoparticles did not affect the structure of g-C3N4 sheets. However, optical results showed that visible light absorption of the material was significantly improved. The synthesized heterojunction photocatalyst exhibited improved photocatalytic performance in the novel degradation of rhodamine B, even upon visible irradiation. The improved photocatalytic performance was ascribed to interfacial contact between g-C3N4 and CoWO4 in a Z-scheme heterojunction in which RGO served as electron mediator accelerating its transfer between g-C3N4 and CoWO4 to minimize recombination of photogenerated electron-hole pairs. Therefore, rhodamine B degradation by CoWO4/RGO/g-C3N4 was 1.87 times higher than pristine g-C3N4. The synthesized heterojunction was relatively stable with no distinct reduction in photocatalytic activity after three recycling runs. The fabrication of heterojunction CoWO4/RGO/g-C3N4 is an efficient strategy to develop high-performance photocatalysts for various photocatalytic applications.