二甲基甲酰胺中Y-Mg-Co合金膜的电化学制备

Electrochemical Preparation of Y-Mg-Co Alloy Film from Dimethylformam ide Bath

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301K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2.95×10-6cm2·s-1和0.11;CoCl2-LiClO4-DMF中Co(Ⅱ)的扩散系数和传递系数为1.34×10-5cm2·s-1和0.24;Y(NO3)3-LiClO4-DMF中Y(Ⅲ)的扩散系数和传递系数为1.68×10-5cm2·s-1和0.10.在铜电极上于-1.50～-3.00V(vsSCE)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%.

The cyclic voltemmetry method was used to investigate the electrochemic al behaviors of Y(Ⅲ),Mg (Ⅱ)and Co (Ⅱ)in Y(NO 3 ) 3 -LiClO 4 -DMF,Mg (ClO 4 ) 2 -LiClO 4 -DMF and CoCl 2 -LiClO 4 -DMF systems on Pt cath-ode.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.T he diffusion coefficient and transfer coefficient of Y(Ⅲ)in Y(NO 3 ) 3 -LiClO 4 -DMF system at 301K are 1.68×10 -5 cm 2 ·s -1 ,0.10;Mg (Ⅱ)in Mg (ClO 4 ) 2 -LiClO 4 -DMF system at 301K are 2.95×10 -6 cm 2 ·s -1 ,0.11;Co (Ⅱ)in CoCl 2 -LiClO 4 -DMF system at 301K are 1.34×10 -5 cm 2 ·s -1 and 0.24respec-tively.Y-Mg-Co alloy films contain ing Y from 3.88%to 58.66%and Mg from 4.51%to 17.52%were prepared by potentiostatic electrodepositi on on Cu substrate with deposition potential ranging from -1.50V to -3.00V(vs SCE).Their surface morphologies were sm ooth,adhesive,uniform and of metallic luster.