在二甲亚砜中La-Ni-Co合金膜的电化学制备

Electrochemical preparation of La-Ni-Co alloy films in DMSO

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 2 98K时 ,利用循环伏安法测定 0 .0 1mol·L-1NiCl2 0 .1mol·L-1LiCl DMSO溶液中Ni2 +的扩散系数、传递系数分别为 3.6× 10 -6cm2 ·s-1和 0 .16 ;利用计时电流法测定 0 .0 1mol·L-1LaCl3 0 .1mol·L-1LiCl DMSO溶液中La3 +的扩散系数为 3.1× 10 -6cm2 ·s-1。在铜电极上于 - 2 .2 5 0～ - 2 .6 5 0V (vsSCE)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%～ 2 4.10 %。在铜电极上于 0 .5～ 0 .8A·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

The cyclic voltemmetry and potential step methods were used to investigate the electrochemical behavior of Ni 2+ and La 3+ in NiCl 2 LiCl DMSO and LaCl 3 LiCl DMSO systems on Pt, Cu and Ni cathodes.Experimental results indicate that the electroreduction of Ni 2+ to Ni is irreversible in one step, the electroreduction of La 3+ to La is quasi reversible.The diffusion coefficient of La 3+ in LaCl 3 LiCl DMSO system at 298?K was 3.1×10 -6 ?cm 2·s -1 .The diffusion coefficient and transfer coefficient of Ni 2+ in NiCl 2 LiCl DMSO system at 298?K were 3.6×10 -6 ?cm 2·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 containing La 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. [