球形Bi2WO6光催化剂的合成与性能

摘要

以Bi(NO)3∙5H2O、Na2WO4∙2H2O为原料，采用水热合成法成功制备出纳米片组成的球形Bi2WO6，并采用X射线衍射(XRD)、扫描电子显微镜(SEM)和紫外-可见漫反射(UV­Vis)技术对其进行分析表征，研究水热温度和反应时间对催化剂合成的影响。通过在紫外及可见光(λ＞420 nm)照射下，降解罗丹明B(RhB、5 mg/L)溶液来评估其光催化活性，并且考察了催化剂投加量、RhB的初始浓度、光源对罗丹明B降解率的影响。结果表明，在180℃水热7 h为最佳制备工艺；催化剂的投加量为2 g/L时，以紫外光为光源，照射120 min对RhB的降解率可达到99.8%。%Spherical Bi2WO6 photocatalysts were synthesized by hydrothermal method with different hydrothermal temperature and reaction time using Bi(NO)3∙5H2O and Na2WO4∙2H2O as raw materials, which were further characterized by X­ray diffraction (XRD), scanning electron microscopy (SEM) and UV­Vis diffusion reflectance spectra techniques. The photocatalytic activity of Bi2WO6 photocatalysts was evaluated by degrading Rhodamine B (RhB, 5 mg/L) under ultraviolet and visible light irradiation (λ>420 nm). The influence of dosage of catalyst, initial concentration of RhB and light source on degradation rate was also investigated. The results indicate that 180 ℃ and 7 h are the proper conditions for preparing Bi2WO6 powders. When the dosage of Bi2WO6 catalyst is 2 g/L and the ultraviolet irradiate time is 120 min, the degradation rate of RhB is up to 99.8%.