低量镱掺杂TiO_2纳米光催化剂的溶胶-溶剂热制备及光活性  

Sol-solvothermal Preparation and Photoactivity of Low Amount Yb-doped TiO_2 Nano-photocatalyst

作　　者：闫盼盼[1] 姜洪泉[1] 卢智宇[1] 李井申[1] 王庆元[1] 

机构地区：[1]哈尔滨师范大学功能材料设计合成与绿色催化黑龙江省高校重点实验室,黑龙江哈尔滨150025

出　　处：《中国稀土学报》2011年第6期681-686,共6页Journal of the Chinese Society of Rare Earths

基　　金：黑龙江省教育厅科学技术研究项目(11551115);哈尔滨师范大学青年学术骨干资助计划项目(08XBSK89)资助

摘　　要：利用溶胶-溶剂热技术制备了锐钛矿型Yb掺杂和未掺杂TiO2纳米粒子,以亚甲基蓝(MB)溶液在紫外光和可见光照射下的光催化脱色率评价其光活性,考察了溶剂热温度、Yb掺杂量和焙烧温度对样品光活性的影响;结合XRD,BET,XPS,FT-IR,DRS和PL表征手段,探讨了Yb掺杂对TiO2光活性的影响机制。结果表明,低量Yb掺杂不仅显著提高TiO2的紫外光活性,也明显提高其可见光活性。Yb掺杂调整TiO2带隙内部电子分布状态,有效抑制光生e-/h+复合,提高量子效率;并且增加表面羟基,增大比表面积,改善表面织构特性,致使紫外光活性提高。然而Yb掺杂并未引起紫外吸收带边红移,其可见光活性的提高应归因于Yb掺杂强化了表面吸附染料的敏化作用。The Yb-doped and un-doped anatase-TiO2 nano-photoeatalysts were successfully synthesized by sol-solvothermal process. Their photoactivities were evaluated by the photocatalytic degradation of methylene blue （MB） in aqueous solution under UV light and visible light irradiation, respectively. The influences of solvothermal temperature, Yb-doping content and calcination temperature on the photoactivities of the samples were investigated. In combination with XRD, BET, XPS, FT-IR, DRS and PL characterization, the effect mechanisms of Yb-doping on the photoactivity were discussed. The results revealed that low content Yb-doping could significantly improve both the UV and visible light photoactivities compared to the un-doped sample. The Yb-doping effectively inhibited the recombination of photogenerated electron-hole pairs, and increased quantum efficiency. In the mean- time, the Yb-doping increased the surface hydroxyl group and the specific area, as well as improved the surface texture properties. All above factors resulted in the enhanced photoactivity of TiO2 under UV light irra- diation. The Yb-doping did not cause red shift of the UV absorption edge of TiO2. Therefore, the increased visible hght photoactivity should be ascribed to the surface dye-sensitization strengthened by Yb-doping.

关 键 词：纳米TIO2 Yb掺杂 溶胶-溶剂热 光活性 染料敏化 稀土 

分 类 号：O643.3[理学—物理化学] O649.4[理学—化学]