TiO_2/BiVO_4复合光催化剂的微波辅助水热法合成及催化性能研究

Synthesis and photocatalytic properties of TiO_2/BiVO_4 photocatalyst by microwave-assisted hydrothermal method

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 NH4VO3 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.