掺杂Ce4+对溶胶-凝胶法制备二氧化钛薄膜的结构和光催化特性的影响

Effect of Ce4+-doping on Structural and Photocatalytic Properties of Sol-gel Prepared Titanium Dioxide Thin-Films

摘要:

采用溶胶-凝胶浸渍提拉法分别在氧化硅和石英衬底上制备了Ce4+掺杂的二氧化钛(TiO2)薄膜,在800℃的退火温度下保温30min。采用X射线衍射仪(XRD)、扫描电镜(SEM)及紫外-可见分光光度计,对TiO2薄膜的结构和光催化性能进行了详细分析,并且进行了对甲基橙的降解实验。研究结果表明:掺杂后的薄膜由锐钛矿向金红石的相转变温度升高。随着掺杂浓度的升高,薄膜经历了由颗粒粒度分明转变到薄膜形成好、未出现明显颗粒的过程,且Ce4+掺杂摩尔百分数为10%的薄膜形成较好。随着Ce4+掺杂浓度升高,TiO2薄膜的光吸收峰先红移再蓝移,紫外区吸收范围先增大后降低。掺杂后薄膜对甲基橙降解率均得到提高,而掺杂10%降解率最大。

Abstract:

Ce-doped titanium dioxide (TiO2) films were prepared on silica and quartz substrates by sol-gel dip-coating. These films were subsequently thermally annealed at 800℃ for 30min, and the structural and photocataytic properties of as-prepared titanium dioxide films were analyzed by X-ray diffraction( XRD), scanning electron microscopy (SEM) and UV-visible spectrophotometer, respectively. The ability to degrade methyl orange of these films was also studied. It is found that the transition temperature of Anatase to Rutile phases increases after doping process. With the increase in Ce4+ doping concentration, TiO2 films experience a procedure from a clear particle-sized morphology to a well-formed film. And the film with 10% mole-percentage doping shows the best film formation. With the increase in Ce4+ doping concentration, the absorption peak of TiO2 films has a blue-shift then a red-shift, resulting in the expansion and then decreasing of absorption in the range of UV area. TiO2 films doped with Ce prepared by this method and annealed at 800℃ for 30min show higher degradation ratio of methyl orange, and the films with 10% mole-percentage Ce4+ doping show the highest photocatalytic properties.