掺杂锡离子对纳米二氧化钛薄膜光催化性能的影响

Effect of Sn^(4+) Dopant on Photocatalytic Performances of Nanocrystalline Titanium Dioxide Thin Films

采用溶胶一凝胶法在玻璃上制备了透明锐钛矿型纳米TiO2薄膜和金属锡离子掺杂的锐钛矿与金红石混晶型纳米TiO2薄膜,并利用X射线衍射(XRD)、原子力显微镜(AFM)、紫外一可见分光光度计对合成的薄膜进行表征。研究了掺杂锡离子对TiO2薄膜吸收光谱及光催化活性的影响,结果表明掺杂锡离子使得TiO2薄膜对入射光的吸收带边发生红移;适量掺杂锡离子能够显著的提高TiO2薄膜的光催化活性。并探讨了镀膜层数对薄膜光催化活性的影响,发现对于掺杂不同浓度锡离子的TiO2薄膜均有其对应的最佳膜层数。

The uniform and transparent nanocrystalline thin film photocatalysts of pure and Sn^4＋ doped titanium dioxide were prepared via sol-gel dip-coating process on the glass substrates. The thin films were characterized by X- ray diffraction （XRD）,atomic force microssopy （AFM） and ultraviolet-visible （UV-VIS） spectrophotometer. It was noted that pure titanium dioxide thin film only had an atase structure, but Sn^4＋ doped ones had a coexistence of anatase and rutile. The effects of different amount of Sn^4＋ dopant on absorption spectra and photocatalyytic activity of TiO2 thin films were studied. It was shown that doping Sn^4＋ caused the red movement of the optical absorption edge for the incoming light, and the doping of Sn^4＋ could grealy improve the photocatalytic activity of titaium dioxide thin films. Besides, the effect of the number of layers on photocatalytic performance was discussed. It was founded that the defferent concentrations of Sn^4＋ doped TiO2 thin films had the optimal layer number,respectively.