(中山大学 化学与化学工程学院， 广州 510275)
摘 要: 研究了二甲亚砜(DMSO)中La3+和Ni2+在Pt，Cu和Ni电极上的电化学行为。结果表明，Ni2+在Pt电极上一步不可逆还原为Ni(0)，La3+在Pt电极上表现为准可逆电极过程。在298 K时，利用循环伏安法测定0.01 mol·L-1 NiCl20.1 mol·L-1 LiClDMSO溶液中Ni2+的扩散系数、 传递系数分别为3.6×10-6 cm2·s-1和0.16；利用计时电流法测定0.01 mol·L-1 LaCl30.1 mol·L-1 LiClDMSO溶液中La3+的扩散系数为3.1×10-6 cm2·s-1 。在铜电极上于-2.250～-2.650 V (vs SCE)下恒电位电解，可获得粘附性好、有金属光泽的LaNiCo合金均匀沉积膜， 其中La的含量可达10.19%～24.10%。在铜电极上于0.5～0.8 A·dm-2下恒电流电解，同样可获得粘附性较好、呈深黑色的LaNiCo合金均匀沉积膜。
关键字: 镧； 电沉积； DMSO； LaNiCo合金； 扩散系数； 传递系数
（School of Chemistry and Chemical Engineering, Zhongshan University, Guangzhou 510275, P.R.China）
Abstract: The cyclic voltemmetry and potential step methods were used to investigate the electrochemical behavior of Ni2+ and La3+ in NiCl2LiClDMSO and LaCl3LiClDMSO systems on Pt, Cu and Ni cathodes．Experimental results indicate thatthe electroreduction of Ni2+ to Ni is irreversible in one step， the electroreduction of La3+ to La is quasireversible．The diffusion coefficient of La3+ in LaCl3LiClDMSO system at 298 K was 3.1×10-6 cm2·s-1．The diffusion coefficient and transfer coefficient of Ni2+ in NiCl2LiClDMSO system at 298*!K were 3.6×10-6 cm2·s-1 and 0.16, respectively．Potentiostatic and current constant electrolysis were used to prepare LaNiCo alloy films. LaNiCo alloy films containingLa from 10.19% to 24.10% were prepared by potentiostatic electrolysis on Cu substrate at deposition potential from -2.250 V to -2.650 V(vs SCE)．Their surfaces were smooth， adhesive， uniform and metallic luster．It is believed that potentiostatic electrolysis is superior to current constant electrolysis．
Key words: lanthanum; electrodeposition; DMSO; LaNiCo alloy films; diffusion coefficient; transfer coefficient
