四氯化钛水解法制备二氧化钛纳米晶的影响因素

摘要

研究了四氯化钛水解法制备的二氧化钛纳米晶工艺中水解温度和硫酸根离子对粉体rn性能的影响．室温下的水解产物为无定形结构，这种粉体有着很大的比表面积，其孔为介孔尺度；添加少量的硫酸根离子使粉体的孔径在2～5nm，最可几孔径为3．8nm．提高水解温度能得到金红石与锐钛矿相的混晶，同样的水解温度下，添加少量的硫酸根离子则为纯锐钛矿相．用 XRD、TEM、DRS和BET等方法对粉体的性能进行了表征，混晶紫外 -可见漫反射光谱不同于两种纳米晶机械混合物．%Effects of sulfate ions and hydrolytic temperature on the TiCl4-derived TiO2 powders properties were investigated in detail. At 20℃, as-prepared powder is amorphous and with huge specific surface area, its average pore diameter is in the mesoporous range. In the presence of a small amount of SO42-, pore diameter distribution is in more narrow range from 2nm to 5nm.Nanocrystalline TiO2 powders can be prepared by raising the hydrolytic temperature, at 70℃ and in the presence of SO42-, the as-prepared powder is pure anatase, however, in the absence of SO4 2-,as-prepared powder is a mixture in both phases. These nanocrystalline TiO2 powders have high specific surface area (as high as 380 m2/g) and also are in ultrafine size (3.5nm) compared with alkoxide-derived TiO2 powders. The properties of these powders were characterized by XRD,TEM,DRS and BET techniques.