Simulating an electrochemical interface using charge dynamics

Abstract

We present a simple classical method for treating charge mobility in metals adjacent to liquid solutions. The method, known as electrode charge dynamics, effectively bridges the computational gap between ab initio calculations on small metal clusters and large-scale simulations of metal surfaces with arbitrary geometry. We have obtained model parameters for a copper (111) metal surface using high-level quantum-mechanical calculations on a 10-atom copper cluster. We validated the model against the classical image-charge result and ab initio results on an 18-atom copper cluster. The model is used in molecular dynamics simulations to predict the structure of the fluid interface for neat water and for aqueous NaCl solution. We find that water is organized into a two-dimensional ice-like layer on the surface and that both Na + and Cl − are strongly bound to the copper. When charging the metal electrode, most of the electrolyte response occurs in the diffuse part of the double layer.

A molecular dynamics simulation study on trapping ions in a nanoscale Paul trap

“…Water molecules were modeled by the TIP3P potential (Jorgensen et al, 1983) based on previous successful modeling of biomolecules and ions using this model (Cheatham and Young, 2000). The polarization interaction between ion/ water and the gold atoms were calculated by the Electrode Charge Dynamics (ECD) (Guymon et al, 2005). The ECD accounts for the polarization effects of finite size metal surfaces and gives a reasonable representation of ion-metal interactions (Payne et al, 2008).…”

Density Functional Theory Methods for Electrocatalysis

“…The interested reader might consider starting with a consideration of electrode-charge dynamics. 13 Density functional theory studies of electrocatalysis require either an approximate model of the electrolyte structure (static solvent, a continuum dielectric, prescribed ion/charge distributions, applied electric fields) or assumptions as to the importance (or lack thereof) of adsorbate-electrolyte interaction. The specific approaches are reviewed and illustrated in examples below.…”

Mechano-electric Characteristics of the Near-surface Layer of Some Materials

“…We formulate one-dimensional correlations for modeling mechanical stress and redistribution of electric charges (free for metals and related to semiconductor or insulator) with r coordinate, where r -radius vector of a point in a spherical coordinate system.The sphere (Vm area, r  R) is placed in a uniform inert gas environment (Vc area, r  R), which pressure is equal p  100 kPa. The electric double layer generated conduction electrons and metal ions and located on the sphere surface on the spherical ring, which thickness h (R  r  R -h) [1].…”

“…As you know, on the border of metal with inert environment the electric double layers (it's correspond to the gradient of the electron density (20 nm)) exists [1]. It's play a decisive role for formation of chemicalreactive properties of solids and interface interaction with other boundary phases.…”