氟掺杂纳米二氧化钛制备及其光催化性能研究进展

Preparation and Photocatalytic Properties of Nanometer Titania Loaded with Fluorine:A Review

氟离子掺杂能够改变TiO2的光生载流子传输、比表面积、孔道结构、表面酸度等本征性质,从而影响光生电子-空穴派对的复合和对母体化合物的吸附,因此氟离子掺杂能够显著提高TiO2的光催化活性,尤其是紫外光下的光催化活性。氟掺杂纳米TiO2在制备过程中,容易受到制备技术、热处理温度、前躯体种类和化学计量等的影响,而使纳米TiO2的晶体结构和表面性质发生变化,这些变化主要体现在如金红石相形成、生成Ti3+、量子产率增加以及改变吸附性(如表面极性)等方面。本文综述了氟修饰TiO2的制备及光活性,主要包括催化剂制备方法、相变过程和母体化合物的矿化。

The intrinsic properties of titanium dioxide could be modified by fluorine doping into crystal lattice, including the photocurrent charge carrier immigration property, the specific surface area, the channel structure, the surface acidity, and others.These changes could influence the recombination of photoinduced electron-hole pairs and the absorption of the parent compound, and thus greatly improve the photocatalysis activity of titanium dioxide, especiallly, under irradiation of ultraviolet light.Although fluorine doping of titanium dioxide was prepared in the laboratory scale, some factors may influence the nano-particle＇s crystal structure and surface properties, such as the preparation method, the annealing temperature, the precursors, the stoichiometric equivalent, etc.Under these influences, the nanometer photocatalyzer may show different photocatalysis activities, which would be embodied in the rutile phase transformation, the formation of Ti3＋, the increase of quantum yield, the change of absorbability（such as surface polarity）, and so forth.Thus the photocatalysis efficiency depends strongly on the methods of fluorine doping , the dosage level and the light source.This paper presents a general review of preparation and photocatalysis activity of fluorine doped titanium dioxide with respect to catalyst preparation;phase transformation process and the mineralization of parent compounds.