Correlative angstrom-scale microscopy and spectroscopy of graphite-water interfaces
Abstract
Water at solid surfaces is key for many processes ranging from biological signal transduction to membrane separation and renewable energy conversion. However, under realistic conditions, which often include environmental and surface charge variations, the interfacial water structure remains elusive. Here we overcome this limit by combining three-dimensional atomic force microscopy and interface-sensitive Raman spectroscopy to characterize the graphite-water interfacial structure in situ. Through correlative analysis of the spatial liquid density maps and vibrational peaks within ~2 nm of the graphite surface, we find the existence of two interfacial configurations at open circuit potential, a transient state where pristine water exhibits strong hydrogen bond (HB) breaking effects, and a steady state with hydrocarbons dominating the interface and weak HB breaking in the surrounding water. At sufficiently negative potentials, both states transition into a stable structure featuring pristine water with a broader distribution of HB configurations. Our three-state model resolves many long-standing controversies on interfacial water structure.
Keywords
Cite
@article{arxiv.2506.09908,
title = {Correlative angstrom-scale microscopy and spectroscopy of graphite-water interfaces},
author = {Lalith Krishna Samanth Bonagiri and Diana M. Arvelo and Fujia Zhao and Jaehyeon Kim and Qian Ai and Shan Zhou and Kaustubh S. Panse and Ricardo Garcia and Yingjie Zhang},
journal= {arXiv preprint arXiv:2506.09908},
year = {2025}
}