Center for Correlated Electron Systems, Institute for Basic Science (IBS) , Seoul 151-747, Korea.
Nano Lett. 2015 Feb 11;15(2):1062-9. doi: 10.1021/nl5040286. Epub 2015 Jan 9.
Scanning probe microscopy (SPM) is a powerful tool to investigate electrochemistry in nanoscale volumes. While most SPM-based studies have focused on reactions at the tip-surface junction, charge and mass conservation requires coupled and intrinsically nonlocal cathodic and anodic processes that can be significantly affected by ambient humidity. Here, we explore the role of water in both cathodic and anodic processes, associated charge transport, and topographic volume changes depending on the polarity of tip bias. The first-order reversal curve current-voltage technique combined with simultaneous detection of the sample topography, referred to as FORC-IVz, was applied to a silver solid ion conductor. We found that the protons generated from water affect silver ionic conduction, silver particle formation and dissolution, and mechanical integrity of the material. This work highlights the dual nature (simultaneously local and nonlocal) of electrochemical SPM studies, which should be considered for comprehensive understanding of nanoscale electrochemistry.
扫描探针显微镜（SPM）是一种强大的工具，可用于研究纳米级体积中的电化学。虽然大多数基于 SPM 的研究都集中在尖端-表面结处的反应上，但电荷和质量守恒要求耦合且固有地非局部的阴极和阳极过程，而环境湿度会显著影响这些过程。在这里，我们探索了水在阴极和阳极过程、相关电荷输运以及根据尖端偏压极性的形貌体积变化中的作用。首次反转曲线电流-电压技术（称为 FORC-IVz）与样品形貌的同时检测相结合，应用于银固体离子导体。我们发现，来自水的质子会影响银离子传导、银颗粒的形成和溶解以及材料的机械完整性。这项工作强调了电化学 SPM 研究的双重性质（同时具有局部和非局部性），这对于全面理解纳米级电化学应该加以考虑。
