When a potential is applied to an electrode immersed in an electrolyte solution, ions with opposite charges accumulate around the electrode, forming an electrical double layer (EDL). Unlike flat electrodes, nanoporous electrodes with pore sizes comparable to the EDL thickness experience overlapping EDLs, altering the electrochemically effective surface area. Although previous research has primarily examined the ion charging dynamics and EDL formation in nanoporous electrodes, the impact of EDL overlap on Faraday reactions remains underexplored. In this study, we examined the influence of EDL overlap on electrochemical reactions within nanoporous electrodes using chronoamperometry and DC and AC voltammetry. We used the electrolyte concentration, measurement duration, overpotential, and electrode material as variables to determine the relationship between the extent of EDL overlap and the electrochemical reaction. The electrolyte concentration-dependent electrochemical reaction due to the EDL overlap was more pronounced for electrodes with faster potential changes, shorter measurement times, lower overpotentials, and slower catalytic activity. This is a unique nanoporous electrochemical phenomenon that is not observed on flat electrodes. These findings provide insight into the utilization of nanoporous electrodes in catalytic and sensor applications.

中文翻译：

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导电纳米孔中受双电层重叠影响的电化学反应


当电位施加到浸入电解质溶液中的电极上时，带相反电荷的离子会在电极周围积聚，形成双电层 （EDL）。与扁平电极不同，孔径与 EDL 厚度相当的纳米多孔电极会与 EDL 重叠，从而改变电化学有效表面积。尽管以前的研究主要检查了纳米多孔电极中的离子充电动力学和 EDL 形成，但 EDL 重叠对法拉第反应的影响仍未得到充分探索。在这项研究中，我们使用计时安培法以及直流和交流伏安法检查了 EDL 重叠对纳米多孔电极内电化学反应的影响。我们使用电解质浓度、测量持续时间、过电位和电极材料作为变量来确定 EDL 重叠程度与电化学反应之间的关系。对于电位变化更快、测量时间更短、过电位较低和催化活性较慢的电极，由于 EDL 重叠导致的电解质浓度依赖性电化学反应更为明显。这是一种独特的纳米多孔电化学现象，在扁平电极上没有观察到。这些发现为纳米多孔电极在催化和传感器应用中的利用提供了见解。