Artemov V G, Uykur E, Kapralov P O, Kiselev A, Stevenson K, Ouerdane H, Dressel M
Center for Energy Science and Technology, Skolkovo Institute of Science and Technology, 121205 Moscow, Russia.
1. Physikalisches Institut, Universität Stuttgart, 70569 Stuttgart, Germany.
J Phys Chem Lett. 2020 May 7;11(9):3623-3628. doi: 10.1021/acs.jpclett.0c00910. Epub 2020 Apr 24.
Water at the solid-liquid interface exhibits an anomalous ionic conductivity and dielectric constant compared to bulk water. Both phenomena still lack a detailed understanding. Here, we report radio-frequency measurements and analyses of the electrodynamic properties of interfacial water confined in nanoporous matrices formed by diamond grains of various sizes, ranging from 5 nm to 0.5 μm in diameter. Contrary to bulk water, the charge-carrying protons/holes in interfacial water are not mutually screened, allowing for higher mobility in the external electric field. Thus, the protonic conductivity reaches a maximum value, which can be 5 orders of magnitude higher than that of bulk water. Our results aid in the understanding of physical and chemical properties of water confined in porous materials and pave the way to the development of new type of highly efficient proton-conductive materials for applications in electrochemical energy systems, membrane separations science, and nanofluidics.
与体相水相比，固液界面处的水表现出反常的离子电导率和介电常数。这两种现象仍缺乏详细的理解。在此，我们报告了对限制在由直径从5纳米到0.5微米不等的各种尺寸金刚石颗粒形成的纳米多孔基质中的界面水的电动性质进行的射频测量和分析。与体相水相反，界面水中携带电荷的质子/空穴不会相互屏蔽，从而在外部电场中具有更高的迁移率。因此，质子电导率达到最大值，可比体相水高出5个数量级。我们的结果有助于理解限制在多孔材料中的水的物理和化学性质，并为开发用于电化学能量系统、膜分离科学和纳米流体学的新型高效质子传导材料铺平道路。
