Fabrication of a zinc tungstate-based a p-n heterojunction photocatalysts towards refractory pollutants degradation under visible light irradiation

The exploitation of new photocatalysts based p-n heterojunction is attracting the attention of the researchers due to its high photocatalytic performance. In this study, ZnWO4/BiOBr heterojunction were successfully prepared via a hydrothermal and a simple deposition method. The obtained ZnWO4/BiOBr composite exhibited superior photocatalytic activity towards refractory pollutants tetracycline (TC) degradation. Among, the samples of ZB-2 (Zn/Bi molar ratios is 0.2) exhibited the best photocatalytic performance. Based on the LC-MS analysis, a possible degradation pathway of TC is also suggested. The optical and electrical properties of the obtained materials demonstrated that the fast transfer of electron-hole pairs was achieved in ZnWO4/BiOBr hybrid though constructing a p-n junction. Furthermore, the activity of the catalyst is still high level without significant loss up to four successive cycles. This work provided a new thought for enhanced visible light photocatalytic performance of zinc tungstate.