熔盐电解法制备CaB_6及其表征

PREPARATION AND CHARACTERIZATION OF CaB_6 BY MOLTEN SALT ELECTROLYSIS

研究了熔盐电解法制备CaB_6的合成工艺,确定了制备CaB_6粉末的合成温度、电解电压和电解时间.同时,对电解所生成的阴极产物的相组成、颗粒尺寸与形貌进行了表征.结果表明,CaCl_2熔盐体系制备CaB_6粉末的基本工艺条件是:Ar气环境保护,电解电压3.0 V,900℃电解30 h.所合成的CaB_6晶体粉末粒径范围为2—8μm,颗粒形态规整,为规则的长方体.对电解过程中阴极进行循环伏安扫描分析,确定硼酸盐向阴极的扩散速率为控制电解过程的重要环节.

CaB6 powder was synthesized by molten salt electrolysis method, and the effects of synthesis temperature, electrolysis voltage and time on the phase composition, particle size and shape of cathode products were analyzed by XRD and SEM. The experimental results show that the best synthesis conditions of CaB6 powder in CaC12 molten salt system are： environment of argon, voltage of 3.0 V, temperature of 900℃ for 30 h, under which the range of CaB6 crystal size is 2--8 μm and the morphology of particles is cuboid massive shape. Using cyclic voltammetry in cathode process, it is Droved that the electrolysis Process is controlled by the diffusion rate of borate to the cathode.