胺类添加剂对制备纳米TiO2颗粒形貌影响研究

Effects of amines additives on the shapes of TiO_2 nanoparticles

用凝胶-溶胶法制备锐钛型纳米TiO2,采用透射电镜和X射线衍射对产物进行了表征,考察了不同胺类添加剂对TiO2形貌的影响。结果表明:产物为锐钛型TiO2;胺类添加剂可改变TiO2形貌,取决于添加剂浓度和pH值。吸附试验表明,椭球形TiO2比立方形TiO2更容易吸附三乙醇胺(TEOA)和二乙三胺(DETA),且DETA的吸附量大于TEOA,对TiO2形貌变化的影响更为明显。胺类添加剂由于在TiO2不同晶面的选择性吸附,使晶体不同晶面的晶体生长速率存在差别,从而导致TiO2形貌变化。

Anatase TiO2 nanoparticles were prepared using a gel-sol method and characterized by transmission electron microscopy and X-ray diffraction patterns. The effects of amines as additives on the shapes of TiO2 nanoparticles were investigated. The results show that the synthesized products are anatase TiO2. The shape changes of TiO2 by amines are related to the concentration of additives and pH values. The results of the adsorption experiments reveal that triethanolamine （TEOA） and diethylenetriamine （DETA） are more easily adsorbed onto spheroidal TiO2 than cuboidal TiO2. The morphology of TiO2 is more easily changed by DETA than by TEOA, this may be related to the greater adsorption amount for DETA than that for TEOA. The shape control by amines as additives can be explained in terms of the selective adsorption of these additives onto different crystal planes of TiO2, leading to the different crystal growth rates of these planes.