Hydrothermal synthesis of type II ZnIn2S4/BiPO4 heterojunction photocatalyst with dandelion-like microflower structure for enhanced photocatalytic degradation of tetracycline under simulated solar light

In this work, the type II ZnIn2S4/BiPO4 heterojunction solar -light driven photocatalysts were synthesized via a facile hydrothermal method, which possessed the unique dandelion-like microflower heterostructure. Among all the ZnIn2S4/BiPO4 with different mass ratios, 70 wt% ZnIn2S4/BiPO(4 )heterojunction displayed the highest photocatalytic activity, which can degrade 84% tetracycline (TC, 40 mg/L) in 90 min and the rate constant is 0.02017 min(-1). It is about 1.89 and 3.14 times that of ZnIn2S4 and BiPO4, respectively. The enhanced photocatalytic activity mainly derives from the formed type II heterojunction between ZnIn2S4/BiPO4 thereby effectively improving the separation efficiency of electron-hole pairs during the photocatalytic reaction. On the basis of the results of active species capturing and ESR experiments, center dot OH and center dot OH2- were proven two predominant species in the photocatalytic system. This work is expected to provide a design opportunity to construct highly efficient BiPO4-based type II heterojunction photocatalysts for photocatalytic applications of degradation on organic pollutants in aqueous environment. (C) 2019 Elsevier B.V. All rights reserved.