水热晶化法合成TiO_2晶须

SYNTHESIS OF TITANIA WHISKERS BY HYDROTHERMAL CRYSTALLIZING PROCESS

以TiCl4为原料 ,KOH为矿化剂 ,采用水热晶化法合成了金红石结构的TiO2 晶须 .采用X射线衍射 (XRD)、透射电镜 (TEM )等对所得产物进行了表征 .实验考察了前驱物粉体Ti(OH) 4用量、反应温度、反应时间及pH值等条件对产物结构和形貌的影响 ,并探讨了金红石结构TiO2 晶须的形成机理 .研究结果表明 ,增大 pH值、提高反应温度及延长反应时间 ,都有利于金红石结构的TiO2 的形成并取向于 ( 110 )面方向生长 ;在本文所建立的强碱性介质中氨分子对TiO2 晶须的生长无显著的影响 .在优化的水热反应条件下 ,即原粉用量为 2 0～ 6 0 g/L ,反应介质pH为 12～ 14 ,反应温度为 14 0～ 180℃ ,反应时间为 6～ 10h ,可获得尺寸均匀、形貌规则、结晶性好的金红石结构TiO2 晶须 .

Titanium oxide whiskers of rutile phase structure were synthesized by means of hydrothermal crystallizing process using titanium tetrachloride as raw materials and potassium hydroxide as mineralizing reagent, respectively. The as_prepared powders were characterized by XRD, TEM. The influences of amorphous titanium tetra_hydroxide precipitates content, hydrothermal processing temperature, reaction time duration and the value of pH on the structure and morphology of the synthesized powders were investigated. It is revealed that raising the processing temperature and the value of pH and to prolonging the reaction time duration are favorable for the formation of rutile phase structure growing selectively in the plane (110) direction. It is also found that there are not marked effects of ammonia on the growth of titanium oxide whiskers in the proposed high alkalinity reaction system. The optimum hydrothermal processing conditions for titanium oxide whiskers of rutile phase structure characterized by even size and morphology and well crystallization are: the titanium tetra_hydroxide precipitates contents of 20-60 g/L, the values of pH of 12-14, the processing temperatures of 140-180 ℃ and the reaction time duration of 6-10 h.