Preparation Of Bismuth Tungstate-based Photocatalyst And Study On Its Photocatalytic Performance

Environmental pollution caused by organic pollutants such as printing and dyeing wastewater is seriously threat to the ecological environment and human health.Photocatalytic oxidation technology,which can convert light energy into chemical energy,has mild reaction conditions and simple operation,and has become a research hotspot for scientists from various countries.Bi₂WO₆ is an excellent semiconductor photocatalyst that can be used to degrade organic pollutants due to its unique layered structure and good visible light response.In this paper,Bi metal is loaded on the surface of Bi₂WO₆,and then BiOBr and Bi/Bi₂WO₆ are compounded together by constructing a heterojunction to improve the photocatalytic performance of the semiconductor photocatalyst.XRD,SEM,FT-IR,Uv-vis,XPS and PL were used to analyze the phase structure,micro-morphology,surface characteristics and light absorption properties,and the photocatalytic activity was evaluated by the degradation of rhodamine B experiment.The main research contents and results of this article are as follows:1. Bi/Bi₂WO₆ composite photocatalyst was prepared by a simple hydrothermal method,and its shape was a layered microsphere structure of 2-3?m.The effects of different factors on the photocatalytic performance were investigated by adjusting the composite mass ratio of Bi and Bi₂WO₆ and the p H value of the precursor solution.The results show that the photocatalytic activity of the as-prepared sample is the highest when the loading of Bi metal is 7%.After 100 minutes of visible light irradiation,the degradation rate of rhodamine B is as high as 100%.When the p H value of the precursor solution is 2.08,the photocatalytic activity and light absorption properties of the composite are optimal.2. BiOBr/Bi/Bi₂WO₆ ternary composite photocatalyst was prepared by hydrothermal method.The effects of different factors on the performance of the ternary composite photocatalyst were investigated by changing the composite mass ratio,reaction temperature and p H value of the precursor solution.The results show that the photocatalytic activity of the as-prepared sample is optimal when the composite mass ratio of BiOBr and Bi/Bi₂WO₆ is 20%,the reaction temperature is 140°C,and the p H value of the precursor solution is 2.07.The cyclic experiments show that the ternary complex is stable and durable during the degradation of organic pollutants.3. The 20%BiOBr/Bi?7%?/Bi₂WO₆ photocatalyst was used in the degradation experiment of rhodamine B to study the effect of process parameters on photocatalytic activity.The analysis results show that when the concentration of rhodamine B is 10 mg/L,the reaction p H is the original rhodamine B solution,and the dosage of the catalyst is 0.1 g/100 m L,the degradation rate of the photocatalytic sample can be maximized.