离子对纳米TiO_2粉体晶型转化的影响

以水解钛酸丁酯沉淀制备纳米 Ti O2 粉体 ,通过对比实验发现 :在同样的处理和煅烧条件下 ,反应系统中 PO4 3-,SO32 -,Si O32 -,Al3+ ,Ca2 +和 K+等离子有利于锐钛矿型 Ti O2 稳定 ,并可保持到较高温区 ;而 CO32 -,NH4 + 等离子是 Ti O2 的金红石晶型促进剂 ,在 70 0℃煅烧 2 h,可使金红石晶型的质量分数由 2 5 %分别提高到 6 6 %和 82 % ,且以 NH4 +为晶型转化促进剂产品中无固溶体为好

Effects of Ions on the Crystal Form Transition of Nanometer TiO2 Particles

Nanometer powder of TiO 2 was prepared from hydrolysis of titanium alkoxide. The effects of cations or anions on the crystal form transition of the TiO 2 particles obtained are studied by adding different salts. From parallel experimental results, it is found that ions, such as PO 4 3- , SO 3 2- , SiO 3 2- Al 3+ , Ca 2+ , and K 1+ , promote anatase crystal form of TiO 2 and keep this form to high temperature, and CO 3 2 and NH 4 1+ might be the accelerators of crystal form transition of TiO 2 from anatase to rutile. The latter two ions change the mass percents of rutile crystal form in the particles of TiO 2 from 25% to 66% and 82% respectively after the calcination of 2 hours at 700℃.