以盐酸甜菜碱(Betaine·HCl)、乙二醇(EG)和六水合硫酸镍(NiSO_4·6H_2O)制备的Betaine·HCl-6EG-nNiSO_4·6H_2O低共熔离子液体为电解液,在碳钢(CS)基体上电沉积出平整致密的金属镍镀层.采用旋转黏度计和电导率仪分别测定了其黏度和电导率.在测试条件下,其黏度为3.918~55.19 m Pa·s,电导率为1.109~0.199 S/m.循环伏安测试结果表明Betaine·HCl-6EG-nNiSO_4·6H_2O(n=0.071)低共熔离子液体中Ni^(2+)在CS电极上的电化学还原过程可以描述为Ni^(2+)→Ni^0,其起始还原电位为-0.56 V.对CS基体上的沉积层进行XRD和EDAS测试,分析结果表明镀层为具有面心立方晶型结构的金属镍.SEM结果表明得到的镍镀层晶粒细小致密且均匀.镀层截面组织金相照片和线性扫描能谱图表明沿CS基体各处均得到厚度分布均匀且与基体结合良好的镍镀层,其厚度约为11μm.
The electrodeposition behaviors of nickel on glassy carbon(GC) and carbon steel(CS) electrodes were investigated in the14.3%-85.7%(mole fraction) betaine.HCl ethylene glycol(EG) ionic liquid using cyclic voltammetry and chronoamperometry.The results indicated that the reduction of Ni(Ⅱ) on CS electrode via a diffusion-controlled quasi-reversible process was much more facile and easier than that occurred on GC electrode,which followed a diffusion-controlled three-dimensional instantaneous nucleation and growth.Scanning electron microscopy was used to observe that the deposit was dense and contained fine crystallites with average size of(80±4) nm.Energy dispersive spectrometer analysis showed that the obtained deposit was metallic nickel.X-ray diffraction spectroscopy indicated that(111) plane was the most preferred crystal orientation.The nickel deposit was luminous and bright,and had good adhesion with the CS substrate.