Chen Chuhongxu, Wang Ziwei, Chen Guilin, Zhang Zhijia, Bedran Zakhar, Tipper Stephen, Diaz-Núñez Pablo, Timokhin Ivan, Mishchenko Artem, Yang Qian
Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, U.K.
National Graphene Institute, University of Manchester, Manchester, M13 9PL, U.K.
Nano Lett. 2025 Jun 11;25(23):9427-9432. doi: 10.1021/acs.nanolett.5c01929. Epub 2025 May 28.
With the advancement of nanoscience, silver/silver chloride (Ag/AgCl) electrodes have become widely utilized in microscale and nanoscale fluidic experiments, because of their stability. However, our findings reveal that the dissolution of AgCl from the electrode in Cl-rich solutions can lead to significant silver contamination, through the formation of silver complexes, . We demonstrate the electrodeposition of silver particles on graphene in KCl aqueous solution, with AgCl dissolution from the electrode as the sole source of silver. This unexpected electrodeposition process offers a more plausible interpretation of the recently reported "ionic flow-induced current in graphene." That is, the measured electronic current in graphene is due to the electrodeposition of silver, challenging the previously claimed "ionic Coulomb drag". More caution is called for when using Ag/AgCl electrodes in microfluidic, and especially nanofluidic, systems because AgCl dissolution should not be neglected.
随着纳米科学的发展，银/氯化银（Ag/AgCl）电极因其稳定性已在微尺度和纳尺度流体实验中得到广泛应用。然而，我们的研究结果表明，在富含氯离子的溶液中，电极上的氯化银溶解会通过形成银络合物导致严重的银污染。我们证明了在氯化钾水溶液中，以电极上氯化银的溶解作为银的唯一来源，银颗粒会在石墨烯上电沉积。这种意外的电沉积过程为最近报道的“石墨烯中离子流诱导电流”提供了更合理的解释。也就是说，在石墨烯中测得的电子电流是由于银的电沉积，这对先前声称的“离子库仑拖拽”提出了挑战。在微流体系统，尤其是纳米流体系统中使用Ag/AgCl电极时需要更加谨慎，因为氯化银的溶解不容忽视。
