Photocatalytic degradation of trichloroethylene on platinum ion-doped TiO2 under visible light irradiation
Photocatalytic degradation of trichloroethylene on platinum ion-doped TiO2 under visible light irradiation
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DOI：
10.1007/s11164-017-3051-z
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发表时间：
2017-07
影响因子：
3.3
通讯作者：
T. Seyama;Toshifumi Tanimura;Keigo Tashiro;S. Yamazaki
中科院分区：
文献类型：
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作者：
T. Seyama;Toshifumi Tanimura;Keigo Tashiro;S. Yamazaki
采用溶胶-凝胶法制备了多孔铂离子掺杂TiO 2（Pt-TiO 2），并在可见光（VL）照射下对气态三氯乙烯（TCE）上级光催化降解。动力学研究进行澄清的掺杂量，空间时间，VL强度，和摩尔分数的TCE，O2，和H2O上降解TCE的效果。在紫外光照射下，Pt-TiO 2的光催化活性与TiO 2相同，表明掺杂的Pt离子没有作为光生空穴和电子的复合中心。根据动力学数据和反应产物，我们得出结论，Pt-TiO 2光催化降解三氯乙烯VL照射下进行类似的TiO 2在紫外光照射下。在管式反应器中，在7.5 × 107 g s mol-1的时空下，我们还进行了TCE的光催化降解实验。TCE完全降解，即在VL照射下达到100%转化率，但仅形成少量的CO2，形成的[CO2]/降解的[TCE]的化学计量比约为0.001。0.33.通过将含有TCE的气流切换到潮湿空气，形成更多的CO2，表明在VL照射下，Pt-TiO 2表面上积累的二氯乙酸酯可光降解为CO2。
Porous platinum ion-doped TiO2(Pt–TiO2) was prepared by a sol–gel method and demonstrated to have superior photocatalytic activity for the photodegradation of gaseous trichloroethylene (TCE) under visible light (VL) irradiation from a xenon lamp equipped with 422-nm cut-off filter. Kinetic studies were performed to clarify the effect of the doping amounts, space times, VL intensity, and mole fractions of TCE, O2, and H2O on the degradation of TCE. Under ultraviolet (UV) irradiation, the photocatalytic activity of Pt–TiO2was the same as that of TiO2, indicating that the doped Pt ion did not act as a recombination center for the photogenerated holes and electrons. Based on the kinetic data and reaction products, we conclude that the photocatalytic degradation of TCE on Pt–TiO2under VL irradiation proceeds similarly to TiO2under UV irradiation. We also performed the photocatalytic degradation of TCE at the space time of 7.5 × 107g s mol−1in a tubular reactor packed with the Pt–TiO2pellets which are more suitable than the Pt–TiO2powder for the practical remediation of the contaminated gas. TCE was completely degraded, i.e. 100% conversion was achieved under VL irradiation but only a small quantity of CO2was formed with the stoichiometric ratio of [CO2]formed/[TCE]degradedof ca. 0.33. By switching the gas stream containing TCE to humid air, more CO2was formed, indicating that the dichloroacetates accumulated on the Pt–TiO2surface are photodegradable to CO2under VL irradiation.