玻碳电极表面复合配位银电结晶机理研究  

Complex Coordination Silver Electrocrystallization Mechanism on Glassy Carbon Electrode Surface

作　　者：黄帅帅[1] 刘诚 金磊 杨防祖[1] 田中群[1] 周绍民[1] HUANG Shuai-shuai;LIU Cheng;JIN Lei;YANG Fang-zu;TIAN Zhong-qun;ZHOU Shao-min(State Key Laboratory of Physical Chemistry of Solid Sufaces,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,Fujian,China)

机构地区：[1]固体表面物理化学国家重点实验室厦门大学化学化工学院,福建厦门361005

出　　处：《电化学》2018年第4期344-350,共7页Journal of Electrochemistry

基　　金：国家自然科学基金项目(No.21621091)资助

摘　　要：以具有实际应用价值的复合配位体系无氰镀银电解液为研究对象,运用循环伏安和电位阶跃等实验方法,结合Scharifker-Hill经典理论模型分析,成功获得了Ag在玻碳电极(GCE)表面电沉积的成核机理及成核动力学参数,并分析了温度对成核方式及成核动力学参数的影响.结果表明,该体系下Ag在GCE表面的电沉积是由扩散控制的不可逆过程,遵循三维瞬时成核生长机理.随着阶跃电位从-750 m V负移至-825 m V,峰值还原电流Im逐渐增大,达到峰值还原电流所需时间tm逐渐缩短,扩散系数D变化不大,基本稳定在(7.61±0.34)×10-5cm2·s-1,成核密度数N0则从3.26×105cm-2提高至10.2×105cm-2.银沉积初期的形貌观察,验证了其三维瞬时成核生长机理.提高温度可以显著改善电解液中具备活性的银配位离子的扩散能力,缩短成核时间,提升成核密度数N0.Cyclic voltammetry and potential step methods were successfully used to study the electrochemical crystallization mechanism of silver deposition on glassy carbon electrode（GCE） in the practical cyanide-free silver plating electrolyte containing composite complexing agents. Scharifker-Hill（SH） theory was used to fitting the experimental data. The results showed that the electrodeposition of silver is a diffusion controlled irreversible electrode process according to three-dimensional instantaneous nucleation mechanism. When the step potential shifted from-750 m V to-825 m V, the peak deposition current Im was increased,while the induced nucleation time tm shortened. The calculated kinetic parameters showed that the diffusion coefficient（D） was basically constant, ranged（7.31 ± 0.34） × 10^5 cm2·s-1, and the active nucleation sites density（N0） increased from 3.26 × 105 cm-2 to10.2×10^5 cm2. The morphologies for the initial deposition of Ag verified the three-dimensional instantaneous nucleation mechanism.Increasing the temperature could significantly improve the diffusion ability of the active silver coordination ions in the electrolyte,which shortened the nucleation time and enhanced the active nucleation sites density N0.

关 键 词：银 复合配位 无氰体系 成核机理 循环伏安 计时电流 

分 类 号：O646[理学—物理化学]