铁、镧共掺杂介孔TiO2微球的制备及光催化性能研究

Preparation and Photocatalytic Activity of La,Fe Co-doped Mesoporous TiO_2 Microspheres

以钛酸异丙酯为钛源,利用三嵌段共聚物EO_(106)PO_(70)EO_(106)(F127)修饰的溶胶-凝胶法合成了La、Fe共掺杂的单分散TiO_2介孔微球。并通过X射线衍射(XRD)、场发射扫描电镜(FESEM)、能谱分析(EDX)、透射电镜(TEM)、BET、X射线光电子能谱(XPS)、紫外-可见光漫反射技术对样品的物相组成及微观结构进行了表征,利用紫外光照射降解亚甲基蓝溶液的方法测定其光催化性能。结果表明:与纯TiO_2介孔微球相比,La3+的掺入抑制了TiO_2晶粒的长大,La3+和Fe3+共掺入TiO_2介孔微球的紫外-可见光的吸收带边发生红移,禁带宽度减小;在紫外光照射下,1at%La3+掺杂以及Fe3+、La3+共掺TiO_2介孔微球的光催化活性均高于纯TiO_2,其中1at%Fe/1at%La-TiO_2的光催化性能最好。

The La/Fe co-doped monodisperse mesoporous TiO2 microspheres were prepared by a triblock copolymer （ EO106 POT0 EO106 （ F127 ） ） modified sol-gel method with titanium （ 1V ） isopropoxide as a titanium source. The prepared sample was characterized by X-ray diffraction, field emission scanning electron microscopy equipped with an energy-dispersive X-ray spectrum, TEM, BET, X-ray photoelectron spectroscopy and UV-visible diffuse reflectance spectroscopy, respectively. The photoeatalytic activities of La/Fe co-doped mesoporous TiO2 microspheres were characterized with methylene blue （MB） solution as a target pollutant under ultraviolet light. The results show that La3＋- doping restrains the increase of grain size, the UV- visible light absorption band of La^3＋/Fe^3＋ co-doped TiO2 exhibited red-shift and the optical band gap of mesoporous TiO2 microspheres is decreased. The photocatalytic activity of La3 ＋ （ 1 at% ） doped, La^3＋ and Fe^3＋ co-doped TiO2 mesoporous microspheres is higher than that of pure TiO2, and the photocatalytic activity of TiO2 co-doped with Fe^3＋ （ 1 at% ） and La^3＋ （ 1 at% ） is notably improved due to the cooperative actions of the two dopants.