Structure and interactions at the Mg(0001)/water interface: An ab initio study
File(s)mg_water_interface_paper_resub_final.pdf (1.74 MB)
Accepted version
Author(s)
Fogarty, Richard
Li, bingxin
Harrison, Nicholas
Horsfield, Andrew
Type
Journal Article
Abstract
A molecular level understanding of metal/bulk water interface structure is key for a wide range of processes including aqueous corrosion, our focus, but their buried nature makes experimental investigation difficult and means we must mainly rely on simulations. We investigate the Mg(0001)/water interface using second generation Car-Parrinello molecular dynamics (MD) to gain structural information, combined with static density functional theory calculations to probe the atomic interactions and electronic structure (e.g calculating the potential of zero charge). By performing detailed structural analyses of both metal-surface atoms and the near-surface water we find, amongst other insights: i) water adsorption causes significant surface roughening, ii) strongly adsorbed water covers only one quarter of available surface sites and iii) adsorbed water avoids clustering on the surface. Static calculations are used to gain a deeper understanding of the structuring observed in MD. For example, we use an energy decomposition analysis combined with calculated atomic charges to show adsorbate clustering is unfavorable due to Coulombic repulsion between adsorption site surface atoms. Results are discussed in the context of previous simulations of metal/water interfaces. The largest differences for the Mg(0001)/water system appear to be the high degree of surface distortion and minimal difference between the metal work function and metal/water potential of zero charge. The structural information in this paper is important for understanding aqueous Mg corrosion, as the Mg(0001)/water interface is the starting point for key reactions. Furthermore, our focus on understanding the driving forces behind this structuring leads to important insights for general metal/water interfaces.
Date Issued
2022-06-28
Date Acceptance
2022-06-02
Citation
Journal of Chemical Physics, 2022, 156 (24)
ISSN
0021-9606
Publisher
American Institute of Physics
Journal / Book Title
Journal of Chemical Physics
Volume
156
Issue
24
Copyright Statement
© 2022 The Author(s). This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in J. Chem. Phys. (in press) (2022); https://doi.org/10.1063/5.0093562
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://aip.scitation.org/doi/10.1063/5.0093562
Grant Number
EP/R005419/1
Subjects
Science & Technology
Physical Sciences
Chemistry, Physical
Physics, Atomic, Molecular & Chemical
Chemistry
Physics
MOLECULAR-DYNAMICS SIMULATIONS
DENSITY-FUNCTIONAL THEORY
TOTAL-ENERGY CALCULATIONS
HYDROGEN EVOLUTION
WATER DISSOCIATION
ZERO CHARGE
SURFACE
METAL
PSEUDOPOTENTIALS
POTENTIALS
02 Physical Sciences
03 Chemical Sciences
09 Engineering
Chemical Physics
Publication Status
Published
Article Number
ARTN 244702
Date Publish Online
2022-06-23