Pt掺杂TiO2纳米粉体的制备及其光催化活性研究

以钛酸丁酯为前驱物,醋酸为酸催化剂,采用溶胶-凝胶法制备掺有不同质量分数Pt的纳米TiO2粉体.通过X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)等现代分析手段对所制备的不同Pt/TiO2纳米粉体的微观结构进行了表征.并以甲基橙染料的光催化降解为模型反应,考察了不同条件下所制备的光催化剂的光催化活性,探讨了纳米粉体中Pt的掺杂量对其光催化活性的影响.实验结果表明,Pt质量分数为0.2%的纳米TiO2粉体的光催化活性最好,过低或者过高的掺Pt量无法提高TiO2的光催化活性,甚至会降低TiO2的光催化活性.

On preparation of nanometer Pt/TiO2 and its photocatalytic activity

The present paper aims at introducing the author's Sol-gel method for preparing Pt/TiO_2.The method is used to produce Pt/TiO_2 at a certain ratio of Ti(OC_4H_9)_4 to CH_3COOH modified by different contents of K_2PtCl_6 through scanning electronic microscopy(SEM),X-ray diffraction(XRD) and X-ray Photoelectron Spectroscopy(XPS),which are used to investigate the texture of prepared catalysts. The author has also studied the photocatalytic performance of prepared catalysts and the influence of the different amounts of Pt content by using methyl orange(MO) as a mode organic pollutant.The results indicate that it is an effective method to add Pt to TiO_2 to enhance the photocatalytic reaction rate.It is proved that Pt can influence the crystal structure,crystal size,surface area,size distribution and bandgap of the catalysts.Moreover,it can also act as a separation center which captures the photogenerated electrons and makes a longer electron-hole pair separation lifetime.It is found that the photocatalytic properties of TiO_2 were enhanced as the contents of Pt were appropriate.The contents which were too low or too high did not enhance it even reduce it.And it is found that the photocatalytic properties of nanometer Pt/TiO_2 were existed as an optimal content of 0.2% Pt.