Abstract
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•A novel Z-scheme heterojunction photocatalyts Ag/g-C3N4/NaTaO3 was fabricated via wet-impregnation and photo-deposition method.•The composite exhibited superior photocatalytic activity under wide-spectrum light.•Z-scheme charge separation protected the highly active photogenerated electrons and holes.•The photocatalytic mechanism was discussed under different light conditions.•A possible photocatalytic degradation pathway of tetracycline (TC) was proposed.
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 photocatalytic 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.