Voltammetric investigation of anodic and cathodic processes at Au(hkl)|ionic liquid interfaces
Voltammetric investigation of anodic and cathodic processes at Au(hkl)|ionic liquid interfaces
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DOI：
10.1016/j.jelechem.2021.115691
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发表时间：
2021-10-08
影响因子：
4.5
通讯作者：
Yoshimoto, Soichiro
中科院分区：
文献类型：
--
作者：
Ueda, Hiroyuki;Yoshimoto, Soichiro
在这项工作中，通过线性扫描伏安法（LSV）、循环伏安法（CV）和双电位步进计时库仑法（DPSCC）系统地研究了金的晶体取向对六种非卤化物基离子液体（IL）和两种碘化物基离子液体界面过程的影响。 IL 的阳离子和阴离子影响 IL 的电双层 (EDL) 区域 (Edl) 的宽度和电化学势窗口 (Epw)。 EDL 区域中的 CV 曲线形状对于每个 Au(hkl)|IL 界面都是唯一的。 1-烷基-3-甲基咪唑碘化物（[Cnmim][I]，n = 4 或 6）中金上碘吸附原子的还原解吸和再吸附也是表面敏感的。还原峰值电流密度与扫描速率成正比，表明该反应涉及吸附的碘。在初始阴极扫描期间解吸的碘吸附原子的量与金单晶电极上碘的单层覆盖相同。估计还原解吸的峰值电位遵循从负到正的顺序：[C6mim][I] < [C4mim][I] 和 Au(100) < Au(111) < Au(110) 。碘还原解吸后，阳离子部分附着在金表面。 [Cnmim]+ 的吸附强度遵循相同的顺序：Au(100) < Au(111) < Au(110)。
In this work, the effect of the crystallographic orientation of gold on the interfacial processes of six non-halidebased ionic liquids (ILs) and two iodide-based ILs was systematically investigated by linear sweep voltammetry (LSV), cyclic voltammetry (CV), and double potential step chronocoulometry (DPSCC). The cation and anion of the IL affected both the width of the electrical double-layer (EDL) region (Edl) and the electrochemical potential window (Epw) of the ILs. The shape of the CV profile in the EDL region was unique for each Au(hkl)|IL interface. The reductive desorption and re-adsorption of iodine adatoms on gold in 1-alkyl-3-methylimidazolium iodide ([Cnmim][I], n = 4 or 6) were also surface-sensitive. The reduction peak current density was proportional to the scan rate, suggesting that the reaction involves adsorbed iodine. The amount of iodine adatoms desorbed during the initial cathodic scan was identical to the monolayer coverage of iodine on gold single crystal electrodes. The peak potential for reductive desorption was estimated to follow the ensuing order from negative to positive: [C6mim][I] < [C4mim][I] and Au(100) < Au(111) < Au(110) . Following reductive desorption of iodine, the cations were partly attached to the gold surface. The adsorption strength of [Cnmim]+ followed an identical order: Au(100) < Au(111) < Au(110).