空心钛酸钡的制备及其形成机理

以二氧化钛（TiO₂）和八水合氢氧化钡Ba（OH）₂·8H₂O]为原料,采用水热合成法,成功制备出具有四方相晶型和空心形貌结构的钛酸钡粉体。利用透射式电子显微镜（TEM）和X射线衍射（XRD）对样品的形貌结构和晶型做了表征,通过研究反应过程中钛酸钡粉体的结构和晶型随时间的变化过程,对空心钛酸钡的形成机理做了详细的探讨,并考察了不同反应温度和钡浓度对钛酸钡粉体结晶和生长的影响。研究结果表明：反应温度和钡浓度会影响钛酸钡粉体的晶型和形貌,并以此提出了一种空心钛酸钡的形成机理;当反应温度为180 ℃、钡浓度为3.0 mmol/L时,能获得粒径分布均匀的四方相晶型的空心钛酸钡粉体。

Preparation and formation mechanism of hollow barium titanate

Barium titanate powders with tetragonal phase polymorph and hollow morphology were successfully synthesized by hydrothermal synthesis using titanium dioxide(TiO2)and eight hydrated barium hydroxideBa(OH)2·8 H2O]as raw materials.The morphologies,structure and polymorph of the products were characterized by transmission electron microscopy(TEM)and X-ray diffraction(XRD),and the formation mechanism of hollow barium titanate were discussed in detail through the study of the dynamic change of the structure and polymorph of barium titanate powders with time in the reaction process.Effects of different reaction temperature and barium concentration on the crystallization and growth of barium titanate were also investigated.Results showed that the reaction temperature and the barium concentration affected the crystal structure and morphology of barium titanate powders,and then the formation mechanism of hollow barium titanate was proposed.Under the conditions of reaction temperature of 180℃and barium concentration of 3.0 mmol/L,uniform particle size distribution of hollow barium titanate powders with tetragonal phase polymorph could be obtained.