Fabrication of ternary NaTaO3/g-C3N4/G heterojunction photocatalyst with enhanced activity for Rhodamine B degradation

Heterojunction photocatalyst with highly efficient photocatalytic activity can enhance the separation efficiency of photogenerated electrons and holes. In this study, in-situ calcination and photochemical reduction self-assembly methods have been proposed to prepare highly efficient ternary NaTaO3 nanocube/g-C3N4 nanosheet/graphene oxide photocatalyst (NaTaO3/g-C3N4/G). In this hybrid structure, NaTaO3 as a kind of stable perovskite with highly positive valance band can form a heterojunction with g-C3N4, leading to the high separation efficiency of electrons and holes. In addition, it is found that the introduction of graphene can further improve the transportation of electrons and extend the light-response spectrum. The optimized ternary composite NaTaO3/g-C3N4/G shows significant enhanced photocatalytic activity with more than 99% removal of Rh B (20 mg/L, 80 mL) within 70 min under visible light, which is 3.1 times faster than that of pure g-C3N4 and 2.1 times faster than NaTaO3/g-C3N4. The photocatalytic mechanism is identified through the free radical quenching experiment.