Pt/TiO2-xNx光催化剂的制备及其产氢活性研究

以四氯化钛(TiCl4)为原料,用溶胶凝胶法制备了纳米氮杂二氧化钛光催化剂(TiO2 xNx),并利用化学还原法在纳米TiO2 xNx 的表面负载了铂单质(Pt/TiO2 xNx).X射线衍射(XRD)结果表明,Pt/TiO2 xNx光催化剂为锐钛矿型结构,由紫外可见漫反射光谱显示催化剂的能隙与纯TiO2 不同,而与TiO2 xNx 相一致.产氢实验结果表明,Pt的负载可以明显提高光催化剂的产氢活性,并且催化剂的产氢活性与Pt的质量分数之间呈现双峰现象,当Pt的质量分数为0 05%和0 35%时,产氢活性分别达到极大值.研究结果表明,当Pt的质量分数为0 05%时,表面Pt粒子的大小约为10 nm且分布均匀,显示该尺度的Pt粒子对于催化剂的产氢活性有较大的促进作用.

Preparation of Pt/TiO2-xNx and Its Photocatalytic Activity of Hydrogen Production

Nanostructured nitrogen-doped titania was prepared by using TiCl_4 as the precursor with sol-gel method, and platinum was loaded on the surface of TiO_(2-x)N_x with chemical reduction method. The (structure) of TiO_(2-x)N_x was demonstrated to be anatase by the means of X-ray diffraction. The ultraviolet visible reflectance spectrum of the catalyst is different from that of TiO_2 but it is consistent with that of (TiO_(2-x)N_x).The activity of hydrogen production raises markedly by loading platinum and shows dual maxima with the increasing of Pt content. When Pt content was 0.05% and 0.35%, the hydrogen production (activity) of Pt/TiO_(2-x)N_x catalysts reaches to the maxima. Scan electronic microscope photos presented that Pt particles agglomerate partially with the increasing Pt contents, and the particle sizes are within 10 and 100 nm. When the content of Pt is 0.05%, the Pt particles distribute uniformly on the TiO_(2-x)N_x surface with an approached size of 10 nm to lead to the maximum photocatalytic activity of hydrogen production.