溶剂热与晶核生长法.ppt

——水热分解 水热合成中主要反应类型 ——水热结晶 比如： Al(OH)3 ? Al2O3. H2O 用新配置的Al(OH)3胶体为前驱物，以水为反应介质，经水热反应和相应的后处理，可得到长针状的Al2O3晶粒；但以醇水混合溶液为反应介质，得到的是板状Al2O3晶粒。 水热合成中主要反应类型 水热合成的主要仪器设备 一、反应釜 1）等静压外热内压容器 2）等静压冷封自紧式高压容器 3）等静压锥封内压容器 4）等静压外热外压容器 二、反应控制系统 三、合成程序 水热合成纳米材料举例 一、介稳材料的合成 二、人工水晶的合成 三、特殊结构、凝聚态与聚集态的制备 四、低维化合物的合成 水热合成纳米材料举例 水热法制备NaFe4P12纳米线 About 0.6 g of FeCl3.6H2O, 1 g of NaOH, and 1 g of white phosphorus were added to 12ml of distilled water in a stainless steel autoclave with a Teflon liner of 16 ml capacity. The autoclave was heated at 165oC for 24 h. The pH values of all the product solutions was about 8, which is much lower than that of the reactant solution (pH12). The dark gray product powder obtained was washed by using HCl (pH=12) and distilled water carefully, then washed with CS2 to eliminate the excess white phosphorus, and finally dried at 60oC in a vacuum drier. 水热法制备纳米线 XRD pattern of the product powder obtained at 165oC for 24h. TEM image of the nanowires. 纳米材料的溶剂热法制备 中国科技大学的钱逸泰等发明了苯热法代替水热法 ——GaN粒子的合成 在真空中Li3N和GaCl3在苯溶液中进行热反应，于280oC制备出30纳米的GaN粒子，这个温度比传统方法的温度低的多，GaN的产率得到80％。 GaN的TEM和XRD图 J. Am. Chem. Soc., 122 (49), 12383 -12384, 2000. 溶剂热法合成多壁碳纳米管 15 mL of benzene was placed into a stainless steel autoclave with 30 mL capacity, and then 2 g hexachorobenzene and 3 g potassium were added. After that, 2 mL of benzene was added until about 80% of the autoclaves capacity was filled. Finally, 100 mg of catalyzer precursor was added. The sealed autoclave was heated at 350o?C for 8 h, and then cooled to room temperature in the furnace naturally. The obtained sample was sequentially washed with absolute ethanol, dilute acid, and distilled water to remove residual impurities, such as chlorides and remaining catalyzer, and then vacuum-dried at 70oC for 6 h. TEM images of multiwall carbon nanotubes (a, b, c, d) obtained. Most nanotubes have straight-line morphology; several nanotubes are shown with a bamboo-like structure (b), and some have open ends (a,