TiO2/BiVO4复合光催化剂的微波辅助水热法合成及催化性能研究

摘要

以硝酸铋和偏钒酸铵为原料,采用微波-辅助水热法合成了BiVO4和TiO2/BiVO4复合光催化剂,借助XRD、UV-Vis和FE-SEM等测试手段对样品进行表征.XRD分析表明,所得BiVO4粉体为单斜晶系,且与TiO2复合后,特征衍射峰宽化,强度降低；FE-SEM显示,所得样品为具有多级结构的球状纳米结构体系；UV-Vis吸收光谱表明,BiVO4粉体和TiO2/BiVO4在400 ～ 600 nm的可见光区域对光响应.根据光吸收特性,选择罗丹明B为模型污染物,考察了样品可见光催化活性.结果表明,TiO2/BiVO4相比BiVO4,具有更高的可见光催化活性.%Using Bi(NO3)3 · 5H2O and NH4VO, as starting materials, photocatalyst BiVO4 was synthesized via hydrothermal process assisted with microwave irradiation, and characterized by the X-ray diffraction (XRD) , field emission scanning electron microscope (FE-SEM) and UV-Vis techniques. Rhodamine B was selected as model pollutant to investigate the photocatalytic activity of BiVO4. The XRD results indicated that the as-synthesized belonged to monoclinic crystal system BiVO4 and after compounding with TiO2 the characteristic diffraction peaks were widened while the intensity reduced. FE-SEM images showed that the as-prepared had sphere morphlogies. UV-Vis absorption spectrum indicated that BiVO4 and TiO2/BiVO4 respond to visible light at 400 ~ 600 nm region. Based on the photo-absorption properties, the photocatalytic experiment was carried out under the Xeon lamp irradiation and TiO2/BiVO4 showed a better visible-light driven photocatalytic activity than that of pure BiVO4.