电场对TiO_2光催化降解亚甲蓝的影响研究

Influences of Electronic Field on the Degradation of Methylene Blue under the Photocatalysis of TiO_2

主要研究了电场对纳米TiO2光催化降解亚甲蓝的影响,在透射电镜(TEM)、X射线衍射(XRD)、比表面积(BET)等方法测定纳米TiO2结构的基础上,结合不同结构纳米TiO2在不同电场强度下催化降解亚甲蓝的性能测试,探讨了电场影响纳米TiO2催化降解亚甲蓝反应机理。结果表明:N及F掺杂溶剂热合成法制备的纳米TiO2颗粒尺寸小且粒径均匀,电场的引入降低了纳米TiO2的光催化性能,而且下降程度与电场强度的变化成反比,反应动力学拟合表明,电场下不同结构的纳米TiO2催化降解亚甲蓝反应均为一级反应。

Nano-sized TiO2 prepared by a sol-gel method was used as photoelectrocatalyst and characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD） and Brunaue-Emmett-Teller （BET）. Electric field assisted photocatalytic properties of TiO2 were characterized by the degradation of methylene blue. Results show that TiO2 possesses small particle size and high effective degradation rate on the degradation of methylene blue. But the photo-degradation performance of TiO2 decreases with the synergy of electric field. It should be resulted from the loss of photocarrier that are neutralized with the positive and negative charge of the electric field before forming over oxidation groups. It could be deduced that the electric field inhibits the photocatalytic performance of TiO2 catalyst, k is also found that the degradation of methylene blue are in accordance with the Langmuir-Chinshelwood function mode