High-efficient charge separation in novel Zn0.5Cd0.5S/Bi4V2O11 heterostructure for boosting photocatalytic Cr (VI) reduction and degradation of tetracycline hydrochloride

Photocatalysis is a green and sustainable technology for the efficient removal of harmful pollutants in water, however, due to the coexistence of multiple pollutants in water system, it is a great challenge to develop multifunctional and efficient photocatalytic systems. Herein, a novel bifunctional Zn0.5Cd0.5S/Bi4V2O11 (ZCS/BVO) heterostructrue photocatalyst was designed and prepared by growing Zn0.5Cd0.5S nanospheres on the surfaces of Bi4V2O11 disc-like nanoflowers through a facial in-situ hydrothermal method. The as-prepared ZCS/BVO heterostructure showed much more enhanced bifunctional visible-light catalytic activity for Cr (VI) reduction and TCH degradation compared with pure Zn0.5Cd0.5S and Bi4V2O11. Among ZCS/BVO samples, ZCS/BVO-10 possessed the best Cr (VI) reduction performance of 86.7 % in 60 min, which was 1.38 and 9.96 times of Zn0.5Cd0.5S and Bi4V2O11. Moreover, ZCS/BVO-10 heterostructure also showed excellent TCH degradation ability of 80.3 % in 48 min, about 2.38 and 3.20 times as high as those of Zn0.5Cd0.5S and Bi4V2O11. The synergistic effect between Zn0.5Cd0.5S and Bi4V2O11 and the close contacted ZCS/BVO heterostructure greatly favored TCH degradation and Cr (VI) reduction reactions due to the increased surface area, enhanced light absorption and boosted charge separation. From the cyclic experiment, ZCS/BVO exhibited high stability and reusability. This work undoubtedly provided a multi-functional and effective photocatalyst for treating various pollutants in water bodies.