Mo掺杂TiO2薄膜的表面润湿行为和光催化性质研究

The Surface Wettability and Photocatalytic Property of Mo-Doped TiO2 Thin Films

采用溶胶-凝胶法并结合薄膜旋涂工艺研究制备Mo掺杂TiO2纳米薄膜。利用X射线衍射分析检测薄膜结构、场发射扫描电镜表征薄膜形貌、X射线光电子能谱分析薄膜表面化学成分,研究结果表明Mo6+以替位离子的形式占据TiO2晶格,引发一定的晶格畸变,但因掺杂量较低,未对薄膜晶粒尺寸及形貌产生较大影响;但是,因掺杂导致表面氧空位和羟基数量的显著增加。我们应用接触角测量仪表征薄膜表面润湿性,证实表面羟基等亲水基团的增加有效促进薄膜表面的亲水性质。通过紫外-可见分光光度计采集薄膜试样的透射光谱,研究发现掺杂导致薄膜吸收边缘蓝移。最后利用自搭建光催化性能测试系统检测薄膜的光催化活性,说明Mo掺杂有助于光催化活性的提高,并且原子数分数为2.0%Mo掺杂的TiO2纳米薄膜具有最佳的光催化效率。

In this work,Mo-doped TiO2 thin films were prepared by sol-gel method and thin film spin coating.The surface morphology of the films was characterized by X-ray photoelectron spectroscopy.The results showed that Mo6+occupied TiO2 lattice in the form of substitutional ions,and caused some lattice distortion.But the doping content is low,which does not have a great effect on the grain size and morphology of the films.However,the surface oxygen vacancy and the number of hydroxyl groups increase significantly due to doping.We used the contact angle meter to characterize the surface wettability of the film,and it was confirmed that the increase of hydrophilic groups such as hydroxyl groups on the surface effectively promoted the hydrophilic properties of the films.The light transmittance spectra of the films were collected by UV-Vis spectrophotometer.It was found that the doping resulted in a blue-shift of absorption edge.Finally,the photocatalytic activity of the films was measured by self-supporting photocatalytic performance test system,which indicated that Mo doping could improve the photocatalytic activity and 2.0 at%Mo-doped TiO2 thin films had the best photocatalytic efficiency.