氟、锌共掺杂TiO_2纳米晶的制备与光催化性能

Preparation and photocatalytic properties of F-Zn-codoped nanocrystalline TiO_2

采用溶胶-凝胶法制备了氟、锌共掺杂TiO2纳米晶光催化剂,分别利用X射线衍射(XRD)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)和紫外-可见(UV-Vis)漫反射光谱对样品进行表征,并通过降解亚甲基蓝实验评估了样品的光催化性能。XRD与TEM表征结果表明,样品为锐钛矿相,平均粒径约16nm。掺杂后,样品光吸收性能未得到显著改善,但其光催化活性却得到显著提高。掺杂离子F-有利于光催化反应过程中羟基自由基的形成,样品光催化活性因而得到显著提高;共掺杂样品中,随着Zn掺杂量的增加,样品光催化活性呈现先增加后减小的变化趋势,Zn掺杂量为2%时,共掺杂样品的光催化性能最佳。

Fluorine and zinc co-doped nanocrystalline TiO2 were prepared by the sol-gel method and investigated by X-ray diffraction (XRD),transmission electron microscopy (TEM),X-ray photoelectron spectroscopy (XPS)and ultraviolet-visible (UV-Vis)diffuse reflectance spectroscopy,respectively.The photocatalytic per-formances of the samples were evaluated by photocatalytic degrading methylene blue.The XRD and TEM re-sults show that all the samples are compose of the anatase phase and the average grain sizes are about 1 6 nm. After the dopings,the absorption properties of the samples can not be obviously enhanced,but the photocata-lytic properties of the samples are all improved.The introduction of F- was beneficial to formation of hydroxyl radicals,resulting in the obvious photocatalytic activity enhancement of the sample.With the increase of Zn do-ping level,the photocatalytic activities of the codoped samples increase and then decrease,gradually.The best photocatalytic property was presented in the codoped sample with 2% Zn doping level.