TiO_2/BiVO_4复合光催化剂的水热法合成及其光催化性能研究

Synthesis of Composite Photocatalyst TiO_2/BiVO_4 by Hydrothermal Method and Its Photocatalytic Property

以Bi（NO3）3·5H2O和NH4 VO3为原料,采用水热法合成了BiVO4和TiO2/BiVO4复合光催化剂,借助XRD、SEM、UV-Vis、IR等测试手段对样品进行了表征。XRD分析表明,所得BiVO4为单斜晶系结构,与TiO2复合后,特征衍射峰窄化,强度略增;SEM显示,BiVO4样品呈现规整的多边立方体形貌,TiO2/BiVO4粉体为规整球状形貌。UV-Vis紫外可见光谱表明,BiVO4和TiO2/BiVO4在400～700nm的可见光区域对光响应。根据光吸收特性,选择亚甲基蓝为模拟污染物,考察了样品的光催化活性。结果表明,与BiVO4相比,TiO2/BiVO4具有更高的可见光催化降解活性,催化降解亚甲基蓝的降解率达到95.9％。

Using Bi（NO3） 3 · 5 H2O and NH4 VO3 as raw materials,photocatalyst BiVO4 and TiO2/BiVO4 were synthesized by hydrothermal method,and characterized by X-ray diffraction （XRD）,scanning electron microscope （SEM）,UV-Vis techniques and infrared spectroscopy （IR）.The XRD result indicated that the as-synthesized belonged to monoclinic crystal system BiVO4 and after compounding with TiO2 the characteristic diffraction peaks were narrowed while the intensity increased.The SEM images displayed that BiVO4 were presented regular multilateral cube morphology,TiO2/BiVO4 as-prepared had regular globular structure system.UV-Vis absorption spectrum indicated that BiVO4 and TiO2/BiVO4 responsed to visible light 400-700 nm region.Based on the properties of optical absorption,selecting methylene blue as a model pollutant,the photocatalytic activity of samples were investigated.The results showed that TiO2/BiVO4 had a better visible light photocatalytic activity than that of pure BiVO4,the degradation rate of methylene blue reached 95.9％.