(中山大學 化學與化學工程學院， 廣州 510275)
摘 要: 研究了二甲亞砜(DMSO)中La3+和Ni2+在Pt，Cu和Ni電極上的電化學行為。結果表明，Ni2+在Pt電極上一步不可逆還原為Ni(0)，La3+在Pt電極上表現為準可逆電極過程。在298 K時，利用循環(huán)伏安法測定0.01 mol·L-1 NiCl20.1 mol·L-1 LiClDMSO溶液中Ni2+的擴散系數、 傳遞系數分別為3.6×10-6 cm2·s-1和0.16；利用計時電流法測定0.01 mol·L-1 LaCl30.1 mol·L-1 LiClDMSO溶液中La3+的擴散系數為3.1×10-6 cm2·s-1 。在銅電極上于-2.250～-2.650 V (vs SCE)下恒電位電解，可獲得粘附性好、有金屬光澤的LaNiCo合金均勻沉積膜， 其中La的含量可達10.19%～24.10%。在銅電極上于0.5～0.8 A·dm-2下恒電流電解，同樣可獲得粘附性較好、呈深黑色的LaNiCo合金均勻沉積膜。
關鍵字: 鑭； 電沉積； DMSO； LaNiCo合金； 擴散系數； 傳遞系數
（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
