在二甲亚砜中La-Ni-Co合金膜的电化学制备
来源期刊：中国有色金属学报2000年第6期
论文作者：袁定胜 刘冠昆 童叶翔
文章页码：919 - 925
关键词：镧； 电沉积； DMSO； La-Ni-Co合金； 扩散系数； 传递系数
Key words：lanthanum; electrodeposition; DMSO; La-Ni-Co alloy films; diffusion coefficient; transfer coefficient
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 NiCl2-0.1 mol·L-1 LiCl-DMSO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 LaCl3-0.1 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La-Ni-Co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La-Ni-Co合金均匀沉积膜。
Abstract:
The cyclic voltemmetry and potential step methods were used to investigate the electrochemical behavior of Ni2+ and La3+ in NiCl2-LiCl-DMSO and LaCl3-LiCl-DMSO 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 LaCl3-LiCl-DMSO system at 298 K was 3.1×10-6 cm2·s-1．The diffusion coefficient and transfer coefficient of Ni2+ in NiCl2-LiCl-DMSO 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 La-Ni-Co alloy films. La-Ni-Co 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．
