纳米复合Sb_2O_3/TiO_2的光催化性能研究

The Enhanced Photo-Catalytic Behavior of Sb2O3/TiO2 Semiconductor Nanopowder

采用溶胶-凝胶法制备复合纳米 Sb2O3/TiO2。 Sb2O3掺入浓度越大，催化剂中锐钛矿相含量越高，晶粒直径与颗粒直径越小，比表面积越大。在 380～ 460nm范围内， Sb2O3/TiO2的反射率则减弱，表明光吸收增强。 XPS分析表明：掺入 2％ Sb2O3，出现新的 Ti2p3/2峰，对应于 Ti3＋，占 9.13％；锑以 Sb3＋、 Sb5＋两种形式存在， Sb5＋占 84.42％、 Sb3＋占 17.58％。以亚甲基蓝溶液光催化降解为模型反应，掺入 2％、 5％ Sb2O3，亚甲基蓝溶液的光催化脱色降解一级动力学常数与总有机炭（ TOC）去除率增大。发射光谱证明： Sb2O3的最佳比例为 2％，当其比例大于 2％时，其电子空穴对的复合率升高，光催化活性下降。

Sb2O/TiO2 samples were prepared by sol-gel process and characterized by means of XRD, TEM, DRS, BET, XPS, photoluminescence (PL) spectra; It had been showed that the mean crystal diameter and mean particle diameter of Sb2O3/TiO2 samples decreased while specific surface area and the percent of anatase increased owing to doping Sb2O3 . The reflectance percent of Sb2O3/TiO2 samples was less than that of pure TiO2 in the range of 380 similar to 460nm. Being a model reaction, the photo-catalytic degradation of methylene blue was investigated in TiO2, and Sb2O3/TiO2 nanopowder suspension irradiated by high-pressure mercury lamp. As a result, the first-order kinetic constant and TOC removal all increased owing to addition of 2% or 5% Sb2O3 to TiO2. XPS analyses showed that a new Ti2p3/2 peak presented at 457. 94eV, corresponding to Ti3+, and the valence state of antimony is Sb3+ (17. 58%) and Sb5+ (82. 42%). The optimum dosage of Sb2O3 was 2%. The PL results showed that the increase of the recombination rate of electron/hole pairs read to the decrease of photo-activity of samples when the dosage of Sb2O3 was more than 2%.