Construction of ternary AuPt/Bi2WO6/ZnIn2S4 heterostructures for photocatalytic degradation of tetrabromobisphenol A

How to fascinate the separation of the photogenerated electrons and holes is very crucial to enhance the photocatalysis of semiconductors. Herein we have prepared AuPt/BWO/ZIS heterostructured photocatalysts by decorating Bi2WO6 (BWO) nanoflakes and AuPt nanoparticles on the surface of ZnIn2S4 (ZIS) hierarchical microspheres. The photocatalysis of the samples was evaluated by degrading tetrabromobisphenol A under simulated-sunlight illumination. It is demonstrated that the ternary AuPt/BWO/ZIS photocatalysts exhibit obviously enhanced photocatalysis in comparison with bare BWO and ZIS as well as the binary BWO/ZIS photocatalysts. The highest photocatalysis is observed for 3%AuPt/40%BWO/ZIS, whose photodegradation performance is improved by 3.9 and 6.2 times over that of single BWO and ZIS, respectively. This phenomenon can be explained due to several reasons: the photocarriers are efficiently separated due to the charge transfer across the BWO/ZIS and AuPt/ZIS interfaces, surface plasmon resonance of AuPt nanoparticles stimulate ZIS to produce additional electron/hole pairs, and the SPR-induced electrons in the AuPt nanoparticles could also take part in the photocatalysis. Additionally, the effect of various factors on the tetrabromobisphenol A degradation was investigated; the degradation pathways of tetrabromobisphenol A and the potential toxicity of the degradation by-products were evaluated.