Title: On the Fundamentals of Interfacial Solvation: Molecular Imaging, Atomistic Simulations, and Statistical Mechanics Models
When: Tuesday, June 13, (2023), 12:00
Place: Department of Theoretical Condensed Matter Physics, Faculty of Sciences, Module 5, Seminar Room (5th Floor).
Speaker: Yingjie Zhang, University of Illinois Urbana-Champaign, USA.
Solvation layers, also called electric double layers (EDLs), exist ubiquitously at all types of solid-liquid interfaces, and serve crucial roles in a large range of natural and engineered processes ranging from biological signal transduction to electrochemical energy conversion and storage. However, the molecular structure of EDLs is still elusive. In this talk, I will discuss our efforts on in situ imaging of EDLs at electrochemical solid-liquid interfaces. In particular, we have developed a technique, electrochemical 3D atomic force microscopy (EC-3D-AFM), to image the electrode surface and EDLs with atomic-scale resolution. We have determined the EDL structure of a large range of electrolytes (ionic liquids, aqueous solutions, and organic electrolytes) on carbon-based electrodes. At heterogeneous electrodes, we find the EDL to be strongly modulated by the local atomic configurations of the electrode surface. To explain and predict the EDL configuration on arbitrary electrode morphologies, we have performed molecular dynamics simulations, and proposed a statistical mechanics model. The latter successfully reproduces and predicts the overall EDL configuration near both the flat, crystalline electrodes and various electrode heterogeneities.