影像科学与光化学 ›› 2009, Vol. 27 ›› Issue (1): 38-47.DOI: 10.7517/j.issn.1674-0475.2009.01.38

• 研究简报 • 上一篇    下一篇

低量La3+掺杂S-TiO2光催化剂的制备、表征及其光催化活性

李慧泉1,2, 范以宁1, 董昆明2, 金凤2, 陈水生2   

  1. 1. 南京大学, 化学化工学院, 化学系, 介观化学教育部重点实验室, 江苏南京210093;
    2. 阜阳师范学院, 化学系, 安徽阜阳236041
  • 收稿日期:2008-03-24 修回日期:2008-09-03 出版日期:2009-01-23 发布日期:2009-01-23
  • 通讯作者: 范以宁,Tel:025 83592909;E-mail:chem612@nju.edu.cn.
  • 基金资助:
    安徽省自然科学基金项目(070416240);安徽省教育厅自然科学研究项目(KJ2007B231);安徽省高等学校青年教师科研项目(2007jq1143,2006jq1224);阜阳师范学院教学研究项目(FJY200741)

Preparation、Characterization and Photocatalytic Activities of Low Amount La3+-doped S-TiO2 Photocatalysts

LI Hui-quan1,2, FAN Yi-ning1, DONG Kun-ming2, JIN Feng2, CHEN Shui-sheng2   

  1. 1. Laboratory of Mesoscopic Materials Science, Department of Chemistry, Nanjing University, Nanjing 210093, Jiangsu, P. R. China;
    2. Chemistry Department, Fuyang Normal College, Fuyang 236041, Anhui, P. R. China
  • Received:2008-03-24 Revised:2008-09-03 Online:2009-01-23 Published:2009-01-23

摘要: 采用溶胶-凝胶-浸渍法制备了La3+/S-TiO2纳米光催化剂,通过XRD、BET、XPS、UV-Vis等手段进行了表征.以甲基橙溶液为光催化降解反应的模型化合物,考察了光催化剂的活性,探讨了低量La3+掺杂对TiO2纳米粒子光催化活性的影响机制.实验结果表明:S改性TiO2后明显提高了TiO2纳米粒子的光催化活性,而La3+掺杂S-TiO2后,进一步提高了TiO2纳米粒子的光催化活性,La3+的最佳掺杂量(相对于TiO2的质量分数)为0.369%;La3+/S-TiO2(ω(La3+)=0.369%)为纳米光催化剂时,甲基橙的脱色率达到92.4%(光照120min);XRD和BET分析表明,低量La3+掺杂抑制了TiO2由锐钛矿向金红石的转变,阻碍了TiO2晶粒的生长,提高了TiO2的比表面积;XPS分析表明,S、La3+掺杂可以导致粉体的表面羟基含量增加,掺杂S以S6+形式置换TiO2晶格中的Ti4+;UV-Vis分析表明,光催化剂La3+/S-TiO2比纯TiO2具有较强的紫外光吸收性能.与纯TiO2相比,La3+掺杂TiO2纳米粒子光催化氧化活性的提高应归因于La3+掺杂增加了表面羟基含量,增大了比表面积,增强了样品表面的紫外光吸收能力.

关键词: 光催化, 二氧化钛, La3+掺杂, 甲基橙

Abstract: La3+/S-TiO2 were prepared by sol-gel-impregnation method and characterized by means of XRD、BET、XPS and UV-Vis.Activities of prepared nano-photocatalysts were evaluated by decolorizing methyl orange solution as model compound to photocatalytic degradation.The mechanisms of effects of low amount La3+-doping on the photocatalytic activity of TiO2 nano-particles were discussed.The results show that S-doping can significantly enhance the photocatalytic activity of TiO2 nano-particles and La3+doped S-TiO2 can further enhance the photocatalytic activity of TiO2 nanoparticles.Under optimal addition amount of La3+ into TiO2 0.369%(mass fraction),decolorizing rate of methyl orange on La3+/S-TiO2 nano-photocatalyst was 92.4% after 120 min irradiation.The analytical results of XRD show that the presence of low amount of La3+in TiO2 can inhibit the phase transformation from anatase to rutile,suppress the growth of TiO2 grains and raise the specific surface area.The analytical results of XPS indicate that S、La3+ doping can result in the increase in the density of the surface hydroxyl,and cationic S6+ is incorporated into TiO2 lattice and substitutes a part of Ti4+.The analytical results of UV-Vis indicate that the La3+/S-TiO2 catalyst has stronger absorption in the ultraviolet region than the pure TiO2.Compared with pure TiO2,the enhanced photocatalytic activity of the La3+ doped TiO2 nano-powders can be due to the increase of the density of the surface hydroxyl and the specific surface area,and the improvement of the ultraviolet light absorption properties of the particle surface.

Key words: photocatalysis, TiO2, La3+-doping, methyl orange

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