La^(3+)离子在EMIMBF_4离子液体中的电化学行为研究

Electrochemical Study on Electrodeposition of La^(3+) in EMIMBF_4 Ionic Liquid

采用三电极体系对La3+离子在0.01mol/LLaCl3-0.1mol/LLiCl-EMIMBF4离子液体电化学还原制备金属镧的电极过程进行了研究。循环伏安法结合恒电位电解法研究结果表明:La3+离子的电化学还原是不可逆过程,还原步骤为一次完成La3++3e-→La。计时电流法结合恒电位电解法研究表明:La3+离子的还原过程受到扩散控制,传递系数和扩散系数分别为0.0492和(1.07～1.19)×10-6cm2/s。

The electrodeposition of lanthanum on a Pt electrode was investigated in 0.01 mol/L LaCl3-0.1 mol/L LiCl-EMIMBF4 ionic liquid.The cyclic voltammetry,chronoamperometry and constant voltage electrolysis techniques were employed.The results of the cyclic voltammogram and the XRD pattern of deposits after electrolysis under constant voltage have supported a one step electrodeposition mechanism of lanthanum,La^3＋ ＋ 3e-→La.The results also indicate that the reduction of La^3＋ ion is irreversible.The transfer coefficient and the diffusion coefficient of La^3＋ ion in 0.01 mol/L LaCl3-0.1 mol/L LiCl-EMIMBF4 ionic liquid are 0.0492 and（1.07-1.19）×10^-6 cm^2/s,respectively.