催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (2): 286-292.DOI: 10.3724/SP.J.1088.2010.00819

• 研究论文 • 上一篇    下一篇

Si 掺杂对 TiO2 空心微球微结构和光催化性能的影响

李纲, 刘昉, 阳启华, 张昭   

  1. 四川大学化学工程学院, 四川成都 610065
  • 收稿日期:2010-08-16 修回日期:2010-09-25 出版日期:2011-01-26 发布日期:2014-06-25

Effect of Si Doping on the Microstructure and Photocatalytic Performance of TiO2 Hollow Microspheres

LI Gang, LIU Fang, YANG Qihua, ZHANG Zhao*   

  1. College of Chemical Engineering, Sichuan University, Chengdu 610065, Sichuan, China
  • Received:2010-08-16 Revised:2010-09-25 Online:2011-01-26 Published:2014-06-25

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摘要： 以葡萄糖、氟钛酸铵和氟硅酸铵为原料, 采用一锅水热合成法在葡萄糖聚合形成的胶体碳球表面原位生成了含有 Ti/Si 物种的前驱物实心微球, 再经高温焙烧脱除碳球模板, 制得 Si 掺杂的 TiO2 空心微球. 应用高分辨透射电镜、X 射线衍射、X 射线光电子能谱和 N2 吸附-脱附等手段对样品进行了表征. 结果表明, Si 进入到 TiO2 的晶格, 形成的 Si–O–Ti 键不仅可有效抑制 TiO2 物相从锐钛矿向金红石转变, 而且还能阻碍 TiO2 纳米晶在焙烧过程中快速长大. 随着 Si 掺杂量的增加, 组成空心微球壳层的 TiO2 纳米晶的平均晶粒度逐渐减小, 而空心微球的比表面积和孔体积逐渐增大. 以亚甲基蓝 (MB) 溶液为模拟污染物, 考察了紫外光下 Si 掺杂 TiO2 空心微球的光催化性能. 结果表明, 随着 Si 掺杂量的增加, TiO2 空心微球对 MB 溶液的降解效率显著升高; 当 Si 的摩尔分数为 0.5 时, 空心微球的光催化效率最高, 是 P25 的 1.25 倍.

关键词: 硅掺杂, 二氧化钛, 碳球模板, 水热合成, 空心微球, 光催化

Abstract: Solid precursory microspheres composed of Ti/Si species were in situ formed on the surface of a colloid carbon microsphere template derived from glucose polymerization and carbonization by a one-pot hydrothermal method using ammonium fluorotitanate, ammonium fluorosilicate, and glucose as source materials. Si-doped TiO2 hollow microspheres were then obtained after calcination and removal of the carbon microsphere template at high temperature. High-resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and N2 adsorption-desorption were used to characterize the samples. The effect of Si doping on the microstructure and photocatalytic performance of the TiO2 hollow microspheres was investigated. The results confirmed that the Si element entered into the lattice of TiO2 and formed Si–O–Ti bond, which could not only effectively suppress the phase transformation from anatase to rutile, but also restrain the rapid growth of TiO2 nanocrystallites during the calcination process. The average grain size of the nanocrystallites constituting the shell of the microspheres decreased gradually and the specific surface area and pore volume of the hollow microspheres increased progressively with the increase in the amount of Si doping. The photocatalytic activity of the Si-doped TiO2 hollow microspheres was measured under ultraviolet light using methylene blue solution as a simulated degradation model. The results demonstrated that the degradation efficiency of TiO2 hollow microspheres enhanced gradually with increasing Si doping in its mol fraction range of 0–0.5. Especially, the degradation efficiency of TiO2 hollow microspheres is 1.25 times that of P25 when the Si mol fraction is 0.5.

Key words: silicon doping, titania, carbon microsphere template, hydrothermal synthesis, hollow microsphere, photocatalysis