Ce掺杂纳米TiO_2/硅藻土复合材料的光催化性能

Photocatalytic Performance of Cerium Doped Nano Titanium Oxide/Diatomite Composites

以提纯硅藻土和钛酸四丁酯为原料,采用溶胶–凝胶法在硅藻土载体表面均匀负载了纳米TiO_2颗粒,并以硝酸铈为掺杂剂。制备了铈掺杂纳米TiO_2/硅藻土复合粉体,对其光催化性能和掺杂机理进行了研究。结果表明:与未掺杂样品相比,铈掺杂量为1.5%(摩尔分数)的复合光催化材料在模拟太阳光照射5 h,对罗丹明B的脱色率达到72.03%,其禁带宽度由3.17 e V减小到2.75 eV。Ce 4f能级在提高可见光吸收、界面间电荷转移及抑制电子–空穴复合方面具有重要的作用。

A composite photocatalyst consisting of nanoparticles of TiO2 immobilized on the diatomite was prepared by a sol-gel method with diatomite and tetrabutyl titanate as raw materials. In order to improve its visible-light photocatalytic activity, cerium nitrate was used as a dopant. The activity of the Ce doped TiO2/diatomite composite photocatalyst was investigated. The results show that the decolorization rate of rhodamine B of the doped photocatalyst is 72.03% under the irradiation of stimulated solar light for 5 h. The band gap energy of Ce doped TiO2/diatomite decreases to 2.75 eV from 3.17 eV of undoped sample. It was indicated that Ce 4f level plays an important role in the improvement of visible light absorption, the interface charge transfer and the suppression of the recombination of electron and hole.