纳米TiO_2薄膜在不同陶瓷表面的负载及其光催化性能研究

Preparation and photo-catalytic properties of nanostructured TiO_2 thin films coated on different ceramics

利用2种不同表面处理的陶瓷作为载体,用溶胶凝胶法在其表面进行了纳米TiO2光催化薄膜的负载。采用X射线衍射法(XRD)、X射线光电子能谱仪(XPS)和扫描电镜(SEM)对薄膜的粒径、横断面及表面组成进行了表征和分析,结果表明,TiO2的平均粒径约为15 nm,釉面陶瓷TiO2薄膜分布均匀,膜厚约为300 nm;无釉陶瓷TiO2薄膜分布不均,膜层不明显;2种载体中的一些基质离子在TiO2薄膜有渗透。苯酚的降解实验表明,以2种不同表面处理的陶瓷为载体的TiO2薄膜对苯酚的降解均符合一级反应动力学,就催化活性而言,TiO2/釉面陶瓷>TiO2/无釉陶瓷,分析认为基质渗透的Ca2+有降低TiO2光催化活性的作用;该薄膜对实际生产多菌灵废水具有催化降解作用。重复降解实验20次,TiO2/釉面陶瓷和TiO2/无釉陶瓷对苯酚的去除率仅分别降低9%和6%。

In the research, titanium dioxide films were coated on two kinds of ceramics by using sol-gel method. XRD, XPS and SEM were used to investigate their photo-catalytic property. The results indicated that the average grainsize of TiO2 was about 15 nm, the TiO2 thin film coated on the vitreous enamel was uniform and continuous, which thickness was about 300 nm, and the films coated on the stoneware were nonuniform ; some ions from the two substrates were observed to permeated to the films by XPS. Photocatatytic degradation experiment showed that phenol can be degraded by the TiO2 thin films coated on the two kinds of ceramics, its kinetics was the first order, the photocatalytic activity followed the decreasing order： TiO2/vitreous enamel 〉 TiO2/stoneware; it was considered that Ca^2＋ permeated from substrates could reduce the photocatalytic activity, and the TiO2 thin films could degrade Badistan wastewater. When the degradation experiments were repeated 20 times for the same film, the removal ration of TiO2/vitreous enamel and TiO2/stoneware were decreased 9% and 6% respectively.