Ag负载WO_3/TiO_2光催化剂的合成及其催化性能

Preparation of Ag Loaded WO_3/TiO_2 Photocatalyst and Its Photocatalytic Performance

以钛酸丁酯、无水乙醇、钨酸铵为原料,采用溶胶-凝胶法合成了WO3/TiO2复合光催化剂;采用光还原技术制备了Ag负载WO3/TiO2光催化剂,借助X射线粉末衍射(XRD)和UV-Vis光谱等技术对样品的组成和光吸收性能进行了表征,并以罗丹明B为模型污染物考察样品的光催化活性。XRD分析表明,所得粉体均为锐钛矿型纳米TiO2,且与WO3复合后,纳米TiO2特征衍射峰宽化,强度降低;UV-Vis光谱分析表明,载银使得催化剂在400—700nm的可见光区域对光响应,且在紫外光区吸收显著增强,对光具有更高的利用率;以罗丹明B为降解物的光催化实验表明,WO3复合对纳米TiO2光催化活性有显著的影响,而载Ag后其光催化活性进一步提高,将该光催化剂用于炼油厂废水的处理,效果较好。

With tetrabutyl titanate,absolute ethyl alcohol and ammonium tungstate as raw materials,WO3/TiO2 composite photocatalyst was synthesized by sol-gel method.Ag loaded WO3/TiO2 photocatalyst was prepared by pohto-reduction technology.The composition and photo-absorption property of the sample were investigated by X-ray powder diffraction（XRD） and UV-Vis spectrum techniques.Rhodamine B was chosen as model pollutant to investigate photocatalytic activity of the sample.The results of XRD analysis indicated that the synthesized powder was anatase nanometer TiO2,and after WO3 was compounded,the characteristic diffraction peaks of nanometer TiO2 were widened while the intensity was reduced.UV-Vis absorption spectrum indicated that Ag doped catalyst had the respond effect on light in visible light region 400—700nm,and the absorbance in UV-light region was observably strengthened,and the photocatalyst had a higher utilization of the light.The photocatalysis experiment results indicated that WO3/TiO2 showed a better photocatalytic activity than that of pure TiO2 with rhodamine B as degradation product,the photocatalytic activity of WO3/TiO2 was further improved when Ag nanoparticles were loaded on the surface of WO3/TiO2.Ag loaded WO3/TiO2 photocatalyst was used to treat the wastewater of oil refinery with satisfactory result.