纳米二氧化钛粉末离子掺杂研究

Research on the metal ions doping for nanometer TiO_2 powders

采用溶胶-凝胶法制备了13种离子掺杂的纳米TiO2光催化剂.系统的考察了它们光催化降解甲基橙的催化活性,并且对其可能的光催化活性的影响因素进行了全面的分析.发现其催化活性的变化与这些离子的掺杂浓度、离子半径、离子的电子亲和势、离子的电子构型、离子掺杂对TiO2造成的晶格畸变以及离子在TiO2晶体中的能级位置等因素有关.其中,掺杂V5+、Ag+、Ni2+、La3+、Fe3+及W6+能够有效提高光催化降解甲基橙的脱色率;而对于Cr3+以及闭壳型的Zn2+、Al3+等对TiO2光催化活性的影响较小,甚至有所降低.

A series of nanometer TiO_2 photocatalysts doped 13 metal ions are prepared by sol-gel.Their photocatalytic activities in photodegradation of methyl-orange have been tested systemically,and the possible factors influenced the photocatalytic activities were analysed.It was found that the catalytic activities of TiO_2 are related with the concentration of dopants,ion radius,ion electronic affinity,ion electronic conformation,crystal lattice aberrance of ion doped TiO_2 and energy levels of impurity ions in TiO_2 crystal,and so on.doping with V^(5+),Ag^+,Ni^(2+),La^(3+),Fe^(3+) and W^(6+) can significantly increase the photoreactivity of TiO_2 powders while Cr^(3+) and the dopants with a closed-shell electronic configuration(Zn^(2+),Al^(3+)) have little influence on the photoreactivity,even decrease it.