微波-凝胶法合成NdCoO3纳米粒子

以硝酸钴、硝酸钕为原料,柠檬酸为络合剂,氨水作反应介质,在微波辐照下,加速溶胶的形成,并采用远红外辐射干燥箱制得复合氧化物的前驱体。采用热重及差热分析法对前驱体进行分析,用马弗炉分别在不同温度下煅烧得黑色粉体。采用X射线衍射和红外光谱等现代分析测试手段对粉体的结构、粒径进行了分析和表征。并将溶胶-凝胶法在800℃制得样品的X射线衍射谱图与微波-凝胶法在相同温度下制得样品的X射线衍射谱图相比较。结果表明,微波-凝胶法在较短的时间(10min)内即生成了钙钛矿型稀土复合氧化物NdCoO3纳米粒子,而溶胶-凝胶法生成相同的复合氧化物则需要2h,体现了微波加热能促进化学反应速率,提高热能利用率。

Synthesis of NdCoO3 Nanopartical by Microwave - Gel Method

The precursors of composite oxides were synthesized by microwave radiation and far infrared radiation heating, in which Co(NO_3)_2·6H_2O and Nd(NO_3)_3·nH_2O were used as starting material, citric acid as complexing agent and NH_3·H_2O as medium. The microwave radioactive heating can accelerate the formation of sol. The precursors were analyzed by TGA-DTA. Black powders were successfully prepared by heating at different temperature in muffle furnace. The structure and crystal size of the powders were characterized by means of physical techniques, including XRD and IR. The XRD chart of sample prepared at 800 ℃ by sol-gel method and the sample prepared by microwave-gel method were compared. The results show that perofskite rare earth compounded oxide NdCoO_3 nanoparticles are formed in 10 minutes, while it is required 2 hours for the sol-gel method. Microwave heating can accelerate chemical reaction rate, utilization ratio of heat energy is enhanced.