摘要
主要采用稳态极化曲线来初步探讨镍阴极电沉积的动力学规律。实验结果表明在NH_3·H_2O浓度为1.25~2.75mol·L^(-1)的范围之内,直接在电极上放电的络合离子形式为Ni(NH_3)^(2+)。拟合计算表明Tafel斜率为0.158V,表观传递系数为0.37,交换电流密度为1.57×10^(-7)A·cm^(-2),电极反应表观活化能为15.78kcal·mol^(-1)。在0.700~0.810V的电位范围内,第一电子传递反应为电极反应的速控步骤,而在较高的阴极化电位下,镍电沉积是混合步骤控制。
Kineties law of nickel electrodeposition from a leaching solutioncontaining ammomia and chloride was investigated by means of steady-state po-larization curves. The results indicate that Ni(NH_3)^(2+) is the direct dischargeion within ammonia concentration range from 1.25 to 2.75mol·L(-1).The ki-netics parameters were determined as follows: Tafel slope is 0.158 V, appar-ent transfer coefficien is 0.37, exchange current density is 1.57 ×10^(-7) A·cm^(-2), electrode reaction apparent activation energy is 15.78 kcal·mol^(-l).The first electron transfer reaction is the rate-determining step in the range ofvoltage from 0.700 to 0.810 V, however the electrode reaction is controlledby mixed step when the cathodic electrode polarization potential is made morenegative.
出处
《科学技术与工程》
2003年第1期22-24,共3页
Science Technology and Engineering
基金
国家自然科学基金(50004005)
浙江省教委科研项目(20000054)