Synthesis of Nano CdZnS/SnS2/SnO2 Heterojunction for Photocatalytic Degradation of Rhodamine B

Abstract

AbstractThe accumulation of organic dyes in water and their consequent detrimental effect to ecological environment have attracted worldwide extensive attention. It is urgent to develop rapid and efficient method to degrade organic dyes. In this paper, an efficient CdZnS/SnS2/SnO2 heterojunction is successfully prepared by sequential template approach and hydrothermal method. Comparison with CdZnS and SnS2/SnO2, the heterogeneous structure of CdZnS/SnS2/SnO2 greatly enhances the photocatalytic degradation ability of Rhodamine B (RhB). The apparent reaction rate of CdZnS/SnS2/SnO2 heterostructure is around 12.71 and 16.69 times higher than those of SnS2/SnO2 and CdZnS, respectively, reaching 0.0267 min−1. After CdZnS/SnS2/SnO2 photocatalysis of RhB solution, the BOD/COD ratio increases from 0.168 to 0.725, indicating that the biodegradability is greatly improved. It has been proved that ⋅OH, ⋅O2−, h+ and e− are the main active species involved in the degradation process. In addition, the CdZnS/SnS2/SnO2 exhibits good stability and reusability, with little change in the photocatalytic activity after five cycles. Its superior removal activity is mainly due to the formation of heterojunction improved light harvesting and enhanced separation efficiency. This work provides a new insight for photocatalytic degradation of organic dye wastewater by solar light.