镧系离子掺杂TiO2的制备及其对咪唑降解反应的光催化活性

 以TiCl4和镧系元素的氯化盐溶液为前驱体,采用溶胶-凝胶法制备了不同含量镧系离子掺杂的TiO2光催化剂,用X射线衍射(XRD)、 光致发光光谱(PLS)、 表面光电压谱(SPS)和X射线光电子能谱(XPS)对催化剂进行了表征. XRD结果表明,样品为锐钛矿和金红石的混晶相,镧系离子未进入到TiO2晶格中. PLS和SPS测定结果表明,随着掺杂离子的不同和掺杂含量的不同,样品的谱强度呈现有规律的变化. 在紫外光照射下,以咪唑为目标降解物比较了催化剂的光催化活性. 结果表明,适当含量的镧系离子掺杂可有效促进TiO2表面光生载流子的分离,从而显著提高其光催化活性.

Preparation of Lanthanide Ions-Doped TiO2 and Its Photocatalytic Activity for Imidazole Degradation

The lanthanide ions-doped TiO_2 samples with different content were prepared by the sol-gel method using titanium tetrachloride and lanthanide chloride as the raw materials.The samples were characterized by(X-ray) diffraction(XRD), photoluminescence spectroscopy(PLS),surface photovoltage spectroscopy(SPS),and (X-ray) photoelectron spectroscopy(XPS).The XRD result indicated that the lanthanide ions did not enter the crystal lattices of TiO_2.The intensity of PLS and SPS related to the surface oxygen vacancies and defects as well as the separation and recombination of photoinduced charge carriers changed with the kinds of lanthanide ions and the dopant content.The photocatalytic activity of the samples for the degradation of aqueous imidazole was tested under UV light.The result showed that the appropriate content of lanthanide dopants could effectively promote the separation effect of surface photoinduced charge carriers on TiO_2,which was responsible for the remarkable increase in photocatalytic activity.