| Zn(Ⅱ)在锌电极上的电沉积机理 | |
| Electrodeposition Mechanism of Zn(Ⅱ) on Zinc Electrode | |
| 摘要: 在Zn(Ⅱ)-NH4Cl准中性体系中,采用循环伏安法(CV)研究了Zn2+在锌电极上的反应方式,通过计时电流法(CA)研究了Zn2+沉积的成核方式,利用交流阻抗谱(EIS)考察了不同过电位时Zn2+沉积的阻抗行为.结果表明:Zn2+的电沉积是一个不可逆电极反应,以两步骤单电子串联的方式进行,第一步为速控步;电极反应的电荷传递系数与锌电极的表面结构有关.在恒电位条件下,体系中锌电极上Zn2+的结晶近似于三维瞬时成核方式.Zn2+的沉积经历了覆盖、吸附成膜、大量晶核形成等过程,该过程随着控制电位的负移由电化学极化过渡到电化学极化-浓差极化混合控制阶段.最后给出了Zn2+在锌电极上电沉积过程的机理. | |
| 关键词: Zn(Ⅱ)-NH4Cl准中性体系 电沉积 循环伏安 计时电流 交流阻抗谱 | |
| 基金项目: 国家自然科学基金(No.51304094)资助项目. | |
| Abstract: Reaction method of Zn2+ on the zinc electrode was researched by cyclic voltammetry(CV). Nucleation mode with Zn2+ was studied by chronoammperometry (CA) and impedance's behavior of the Zn2+ in the different overpotential deposition periods was investigated by electrochemical impedance spectroscopy (EIS) in Zn(Ⅱ)-NH4Cl quasi neutral system. The results showed that the electrodeposition of Zn2+ is an irreversible electrode reactions and conducts by continuous two steps of single electron in which the first step is controlled by speed. The electron transfer coefficient of electrode reaction is related to the surface of zinc electrode structure. Under the condition of constant potential, the crystallization of Zn2+ is approximate to three-dimensional instantaneous nucleation on zinc electrode in this system. Depositing of Zn2+ has experienced the process of covering, adsorption film and the formation of large number of nucleation. The process was controlled by electrochemical polarization firstly and then the electrochemical polarization-concentration polarization mixed control with the control potential negatively shifted. Finally the mechanism of electrodeposition process with Zn2+ on the zinc electrode was given. | |
| Keywords: Zn(Ⅱ)-NH4Cl quasi neutral system electrodeposition cyclic voltammetry chronoammperometry electrochemical impedance spectroscopy | |
| 投稿时间：2015-10-14 修订日期：2016-01-19 | |
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| 徐双全,刘春侠,沈庆峰,张涛,倪源,俞小花.Zn(Ⅱ)在锌电极上的电沉积机理[J].无机化学学报,2016,32(3):386-392. | |
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