Ce/TiO_2纳米复合粉体的制备及其性能评价

Preparation and evaluation of Ce/TiO_2 nanocomposite photocatalyst

以锐钛矿型纳米TiO2和硫酸铈为主要原料,采用浸渍法制备了Ce/TiO2纳米复合材料。采用滴定法研究TiO2对Ce4+的吸附,结果表明,在pH值为2-7的范围内TiO2对铈离子的吸附量接近100%。采用X射线衍射(XRD)进行物相结构分析,发现在700℃下焙烧仍保持锐钛型结构,而在800℃下焙烧出现了金红石型TiO2和CeO2,说明铈离子的存在减缓了TiO2的晶型转变。最后以甲基橙为目标降解物评价了Ce4+/TiO2复合粉体的光催化反应活性。

The nanocomposite photocatalysts, titanium oxide （TiO2） doped by Ce^4＋ , were prepared by impregnation method. The photoeatalysts were investigated by X-ray diffraction （XRD） , transmission electron microscope （TEM） and UV-Vis transmittance spectra. The adsorbing ability of TiO2 for Ce^4＋ was studied by titration method. The results show that the adsorbing rate nearly reaches 100% in the range of pH=2.0-7.0. It is found that the presence of the Ce^4＋ ions in the TiO2 elevates the phase transforming temperature. The photoeatalysts remain anatase calcined at 600℃ and 700℃, and the rutile TiO2 and CeO2 begin to appeare when it is calcined at 800℃. The photoeatalytie activity is evaluated by photodegradation of methyl orange （MO） in solution. The results indicate that TiO2 doped by Ce^4＋ extend absorption edge and show much higher photoeatalytie activity compared to pure TiO2 particles.