水热-热解法合成不同形貌的α-Al_2O_3粉体

Controlled Synthesis of α-Al_2O_3 of Different Shapes via the Hydrothermal-Pyrolysis Method

以Al2(SO4)3·18H2O、尿素为原料,采用水热-热解法制备α-Al2O3粉体。用XRD、SEM对产物进行表征,研究了水热反应时间、表面活性剂PEG2000、添加剂AlF3等因素对产物形貌的影响。结果表明:120℃水热反应6 h,前驱体经1200℃煅烧,用Al2(SO4)3·18H2O/尿素体系得到球形α-Al2O3;分别以表面活性剂PEG2000和AlF3为添加剂,得到纤维状及片状α-Al2O3。讨论了不同形貌α-Al2O3的形成机制。

α-AI203 powders with different shapes were prepared from the reaction of aluminum sulfate octadecahydrate and urea by hydrothermal pyrolysis method. The as-prepared products were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The effects of reaction time and additives such as PEG 2000 and AIF3 on the morphologies of the products were evaluated. Without additives, spherical α-AI203 powders were obtained at 120 ℃for 6 h followed by calcination at 1200 ℃. When using PEG 2000 and AIF3 as additives, fiber- and tabular-shaped α-AI203 powders were obtained under the same reaction conditions respectively. In addition, the reaction mechanisms of the formation of α-AI203 powders with different shapes were discussed.