Inhomogeneous distribution of electrolyte ions at solid–solution interfaces at the nanometer scale is known to contribute to several emerging transport phenomena discovered from various nanopores or nanochannels. The topic has attracted extensive research effort, aiming to achieve better energy harvesting, storage, conversion, desalination and separation, sample concentration, stochastic sensing, and so on. In this report, dynamic ion concentration polarization inside charged conical nanopores, one of the two characteristics to describe the electrical double layer (EDL) structure (charge distribution and potential profile), is quantified. The hysteresis in the ion transport or redistribution in single nanopores is determined from the pinched current–potential loops by time‐dependent electrokinetic measurements. The extent of polarization in ion concentrations over different timescales, or residual charges during the transition from one ion distribution/EDL structure to another, is quantitated from the area enclosed in the hysteresis current loops. The ratio of the residual charges during the high/low conductivity states is correlated with the current ratio at the threshold potentials (rectification factor), which, in turn, serves as a convenient parameter to estimate the charge transport hysteresis. By adjusting the solution pH and ionic strength, and under different potential sweeping rates, the dynamics of ion enrichment or depletion is elucidated, respectively, and successfully described with a simple capacitive charging model. Taken together with our previous reports of the memristive ion transport in conical nanopores/nanopipettes and the physical meaning of the unique non‐zero cross‐point potential, a comprehensive view of the charge redistribution and EDL dynamics at nanoscale interfaces is offered.

中文翻译：

---

单个锥形纳米孔中离子的动态富集和耗尽中的磁滞电荷

已知在纳米级的固溶界面上，电解质离子的不均匀分布会导致从各种纳米孔或纳米通道中发现的几种新兴的传输现象。该主题吸引了广泛的研究工作，旨在实现更好的能量收集，存储，转换，淡化和分离，样品浓缩，随机感测等。在此报告中，对带电圆锥形纳米孔内部的动态离子浓度极化进行了量化，这是描述双电层（EDL）结构（电荷分布和电势分布）的两个特征之一。在单个纳米孔中，离子迁移或重新分布中的磁滞是通过与时间相关的电动学测量从夹紧的电流-势环中确定的。离子浓度在不同时间范围内的极化程度，或从一种离子分布/ EDL结构过渡到另一种离子分布/ EDL结构过程中的残留电荷，是根据磁滞电流回路中封闭的区域进行量化的。高/低电导率状态下的剩余电荷比率与阈值电势下的电流比率（整流因子）相关，而后者又可以用作估算电荷传输滞后的方便参数。通过调节溶液的pH值和离子强度，并在不同的电势扫描速率下，分别阐明了离子富集或耗尽的动力学，并通过简单的电容充电模型成功地进行了描述。