ZnCl_2-EMIC离子液体中电沉积锌

Electrodeposition of zinc from zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt

采用ZnCl2-EMIC离子液体,用电化学方法对体系在镍电极和钨电极上的反应阴极过程进行研究,分析锌沉积机制,并用直流和脉冲电源进行电沉积实验,研究电流密度、温度和脉冲参数等因素对镀层的影响。结果表明:阴极反应为准可逆反应,锌离子在镍电极和钨电极上形核是三维瞬时形核半球形扩散长大过程,直流电流密度为4 mA/cm2,温度为80℃时,镀层质量最好;脉冲电沉积得到的镀层要优于直流电沉积得到的镀层,尤其在脉冲宽度为2 ms,脉冲间隔为8 ms,电流密度为8 mA/cm2时,得到的镀层光滑而均匀,颗粒大小接近0.3μm。

The electrodeposition of zinc from zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt was adopt to study the process of the cathode reaction. The electrodeposition was carried out with direct current and impulse current, The factors influencing the coating were studied, The result indicate that： the electrodeposition of zinc on nickel and tungsten substrates involves instantaneous three-dimensional nucleation. The coating is the best when the current density is 4 mA/cm2 and the temperature is 80℃. The coating by the method of the impulse electrodeposition is better than the direct current electrodeposition. Especially whenfis 100 Hz, ton/toff is 2/8 and J is 8 mA/cm2, the coating is clean and uniformity. The crystal size is nearly 0.3 μm.