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Structure and interactions at the Mg(0001)/water interface: An ab initio study
- Source :
- The Journal of Chemical Physics. 156:244702
- Publication Year :
- 2022
- Publisher :
- AIP Publishing, 2022.
-
Abstract
- A molecular level understanding of metal/bulk water interface structure is key for a wide range of processes, including aqueous corrosion, which is our focus, but their buried nature makes experimental investigation difficult and 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 that, among other insights: (i) water adsorption causes significant surface roughening (the planar distribution for top-layer Mg has two peaks separated by [Formula: see text]), (ii) strongly adsorbed water covers only [Formula: see text] 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 that adsorbate clustering is unfavorable due to Coulombic repulsion between adsorption site surface atoms. Results are discussed in the context of previous simulations carried out on other metal/water interfaces. The largest differences for the Mg(0001)/water system appear to be the high degree of surface distortion and the minimal difference between the metal work function and metal/water potential of zero charge (at least compared to other interfaces with similar metal–water interaction strengths). 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.
- Subjects :
- ZERO CHARGE
Science & Technology
MOLECULAR-DYNAMICS SIMULATIONS
HYDROGEN EVOLUTION
02 Physical Sciences
Chemical Physics
SURFACE
Chemistry, Physical
PSEUDOPOTENTIALS
Physics
TOTAL-ENERGY CALCULATIONS
POTENTIALS
General Physics and Astronomy
Physics, Atomic, Molecular & Chemical
09 Engineering
DENSITY-FUNCTIONAL THEORY
Chemistry
METAL
Physical Sciences
WATER DISSOCIATION
Physical and Theoretical Chemistry
03 Chemical Sciences
Subjects
Details
- ISSN :
- 10897690 and 00219606
- Volume :
- 156
- Database :
- OpenAIRE
- Journal :
- The Journal of Chemical Physics
- Accession number :
- edsair.doi.dedup.....8148ede82c01a819a37df681d8af1296