水热合成金红石型TiO_2纳米晶及形成机理

Hydrothermal Synthesis and Formation Mechanism of Rutile Nanocrystalline TiO_2

以TiCl_4原料加水配制成0.5～2.0mol/L的TiOCl_2溶液,在反应温度为120～180℃时可获得纳米级针形(轴比4～5)及球形8～10nm的金红石粒子。研究了升温速率、搅拌等对金红石型TiO_2纳米晶的粒径及形貌的影响。使用TEM及XRD对产物粒子进行了表征,并初步探讨了金红石纳米晶的形成机理。结果表明:对于一定浓度的TiOCl_2溶液,当反应温度高于140℃时,可生成纯相金红石型TiO_2纳米晶粒,搅拌和提高升温速率有利于生成纳米球形颗粒。

Nanocrystalline TiO2 was prepared at 120-180℃ from TiOCl2 aqueous solution which concentration was 0.5-2. 0mol/L. The obtained TiO2 particles characterized by TEM and XRD were proved to be nanorod (axis ratio 4-5) or sphere(8-10nm) with rutile structure. The influence of the rate of temperature-rising and stirring on the morphology and size of rutile nanocrystalline TiO2 was studied systematically. It is shown that pure rutile nanocrystalline TiO2 can be synthesized from the TiOCl2 aqueous solution when the reaction temperature is above 140℃. Stirring and increasing the rate of temperature-rising can make it easier to form sphere TiO2 nano-particles. On the basis of the analysis of experimental results, the formation mechanism of nanocrystalline TiO2 was discussed.