Enhanced photocatalytic activity of ternary Ag/g-C3N4/NaTaO3 photocatalysts under wide spectrum light radiation: The high potential band protection mechanism

Constructing heterojunction photocatalyst is an effective method to enhance the separation of photogenerated electron and hole and benefit the wide-bandgap photocatalyst with significant visible light response ability. In this study, a novel and highly efficient ternary photocatalyst was prepared by depositing Ag nanoparticles on the surface of graphitic carbon nitride nanosheets (g-C3N4)/NaTaO3 nanohybrid. It showed an enhanced photo catalytic degradation of tetracycline (TC), rhodamine B (RhB) and phenol under wide-spectrum light irradiation. Compared to pure NaTaO3, g-C3N4 and binary g-C3N4/NaTaO3, Ag/g-C3N4/NaTaO3 displayed enhanced photodegradation efficiency with 95.47% removal of TC (20 mg/L) in 60 min under visible light irradiation. From the free radical quenching experiment and ESR characterization results, the charge transfer process can be identified as a Z-scheme transfer mechanism, which can significantly enhance the charge separation rate and protect the high potential valence band (VB) of NaTaO3 and conduction band (CB) of g-C3N4. This work provides a new promising approach for designing novel Z-scheme photocatalysts.