Photocatalytic degradation of 2-mercaptobenzothiazole in aqueous La3+-TiO2 suspension for odor control
Photocatalytic degradation of 2-mercaptobenzothiazole in aqueous La3+-TiO2 suspension for odor control
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DOI：
10.1016/j.apcatb.2003.10.003
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发表时间：
2004-03-31
影响因子：
22.1
通讯作者：
Hou, MF
中科院分区：
文献类型：
--
作者：
Li, FB;Li, XZ;Hou, MF
采用溶胶-凝胶法将镧离子掺杂到TiO 2结构中，制备了La 3 +-TiO 2光催化剂。然后通过XRD和XPS分析对催化剂样品进行表征。分析结果表明，La掺杂抑制了TiO 2的相变，提高了TiO 2结构的热稳定性。此外，随着镧掺杂量的增加，催化剂的晶粒尺寸减小，表面Ti 3+含量增加。以2-巯基苯并噻唑（MBT）为模型化合物，研究了La 3 +-TiO 2催化剂的吸附等温线和光催化活性，并以MBT为模型化合物，考察了其在水溶液中的光催化降解性能.实验结果表明，随着La掺杂量的增加，La 3 +-TiO 2催化剂的吸附量和吸附平衡常数均增大。研究了不同La ~（3+）-TiO_2催化剂光降解MBT的动力学。实验结果表明，当镧离子掺杂量为1.2%时，MBT的光降解率最高。结果表明，La 3 +-TiO 2催化剂对MBT光催化降解的促进作用主要是通过提高有机物在催化剂悬浮液中的吸附和Ti 3+的存在促进了电子-空穴对的分离两个方面来实现的。(C)2003 Elsevier B. V.保留所有权利。
The La3+-TiO2 photocatalysts were prepared by doping lanthanum ion into TiO2 structure in a sol-gel process. The catalyst samples were then characterized by XRD and XPS analyses. The analytical results demonstrated that the lanthanum doping could inhibit the phase transformation of TiO2 and enhance the thermal stability of TiO2 structure. In addition, it was found that the lanthanum doping could reduce the crystallite size and increase the Ti3+ content on the surface of the catalysts with the increase of lanthanum doping. With a purpose of odor control, 2-mercaptobenzothiazole (MBT) was used in this study as a model chemical and both the adsorption isotherm and photocatalytic activity of the La3+-TiO2 catalysts were evaluated based on the MBT photodegradation in aqueous solution. The experimental results showed that both the adsorption capacity and adsorption equilibrium constants of the La3+-TiO2 catalysts increased with an increase of lanthanum doping. The kinetics of the MBT photodegradation using different La3+-TiO2 catalysts was also studied. The experiments demonstrated that an optimum doping of lanthanum ion at 1.2% achieved the highest MBT photodegradation rate. It was concluded that the enhancement of MBT photodegradation using the La3+-TiO2 catalysts mainly involved in both the improvement ofthe organic substrate adsorption in catalysts suspension and the enhancement of the separation of electron-hole pairs owing to the presence of Ti3+. (C) 2003 Elsevier B.V. All rights reserved.