二甲基甲酰胺中Y-Mg-Co合金膜的电化学制备

研究了二甲基甲酰胺（DMF）中Y(Ⅲ) 和Mg(Ⅱ) 及Co(Ⅱ)在Pt电极上的电化学行为.结果表明,Y(Ⅲ)、Mg(Ⅱ)及Co(Ⅱ)在Pt电极上一步不可逆还原为Y(0)、Co(0)和Mg(0).在301 K时,利用循环伏安法分别测定出Mg(ClO4)2-LiClO4-DMF中Mg(Ⅱ)的扩散系数和传递系数为2.95×10－6 cm2•s－1和0.11；CoCl2-LiClO4-DMF中Co(Ⅱ)的扩散系数和传递系数为1.34×10－5 cm2•s－1和0.24；Y(NO3)3-LiClO4-DMF中Y(Ⅲ)的扩散系数和传递系数为1.68×10－5 cm2•s－1和0.10.在铜电极上于－1.50～－3.00 V(vs SCE)下恒电位电沉积,得到黑色、光滑致密、粘附性好的Y-Mg-Co合金膜,其中Y含量为3.88％～58.66％;Mg含量为4.51％～17.52％.

Electrochemical Preparation of Y-Mg-Co Alloy Film from Dimethylformamide Bath

The cyclic voltemmetry method was used to investigate the electrochemical behaviors of Y（Ⅲ）,Mg（Ⅱ）and Co（Ⅱ） in Y(NO3)3-LiClO4-DMF,Mg(ClO4)2-LiClO4-DMF and CoCl2-LiClO4-DMF systems on Pt cathode. Experimental results indicate that the electro-reduction of Y（Ⅲ）,Mg（Ⅱ）and Co（Ⅱ） to Y、Mg and Co is an one-step irreversible in process. The diffusion coefficient and transfer coefficient of Y（Ⅲ）in Y(NO3)3-LiClO4-DMF system at 301 K are 1.68×10－5 cm2•s－1,0.10; Mg(Ⅱ)in Mg(ClO4)2-LiClO4-DMF system at 301 K are 2.95×10－6 cm2•s－1,0.11; Co(Ⅱ) in CoCl2-LiClO4-DMF system at 301 K are 1.34×10－5 cm2•s－1 and 0.24 respectively. Y-Mg-Co alloy films containing Y from 3.88％ to 58.66％ and Mg from 4.51％ to 17.52％ were prepared by potentiostatic electrodeposition on Cu substrate with deposition potential ranging from －1.50 V to －3.00 V(vs SCE).Their surface morphologies were smooth, adhesive, uniform and have metallic luster.