Mapping electrostatic potential in electrolyte solution
Abstract
Mapping the electrostatic potential (ESP) distribution around ions in electrolyte solution is crucial for the establishment of a microscopic understanding of electrolyte solution properties. For solutions in the bulk phase, it has not been possible to measure the ESP distribution on Angstrom scale. Here we show that liquid electron scattering experiment using state-of-the-art relativistic electron beam can be used to measure the Debye screening length of aqueous LiCl, KCl, and KI solutions across a wide range of concentrations. We observe that the Debye screening length is long-ranged at low concentration and short-ranged at high concentration, providing key insight into the decades-long debate over whether the impact of ions in water is long-ranged or short-ranged. In addition, we show that the measured ESP can be used to retrieve the non-local dielectric function of electrolyte solution, which can serve as a promising route to investigate the electrostatic origin of special ion effects. Our observations show that, interaction, as one of the two fundamental perspectives for understanding electrolyte solution, can provide much richer information than structure.
Cite
@article{arxiv.2311.00387,
title = {Mapping electrostatic potential in electrolyte solution},
author = {Bo Huang and Yining Yang and Ruinong Han and Keke Chen and Zhiyuan Wang and Longteng Yun and Yian Wang and Haowei Chen and Yingchao Du and Yuxia Hao and Peng Lv and Haoran Ma and Pengju Ji and Yuemei Tan and Lianmin Zheng and Lihong Liu and Renkai Li and Jie Yang},
journal= {arXiv preprint arXiv:2311.00387},
year = {2024}
}
Comments
The small-angle signal in Fig. 2 C-H is highly likely to be an experimental artifact, due to that the electron beam is placed too close to the edge of the liquid sheet. This artifact invalidates the main conclusion of the paper