Halide adsorption on single-crystal silver substrates: dynamic simulations and ab initio density functional theory.

Area of Science:

• Surface Science
• Electrochemistry
• Computational Materials Science

Background:

• Electrochemical deposition of adlayers is crucial for materials science.
• Previous models, like lattice-gas, have limitations in representing adparticle positions.
• Understanding adlayer behavior on single-crystal substrates is key for controlling surface properties.

Purpose of the Study:

• To investigate the static and dynamic properties of a bromine adlayer on a single-crystal silver surface (Ag(100)).
• To develop and utilize an off-lattice model for a more realistic simulation of adlayer behavior.
• To compare the off-lattice model's predictions with experimental observations and previous lattice-gas models.

Main Methods:

• Development of an off-lattice model for adlayer simulation, allowing continuous particle positions.
• Approximation of substrate interactions using a corrugation potential derived from density functional theory (DFT) calculations.
• Application of Monte Carlo and Langevin simulations to study adlayer dynamics and thermodynamics.

Main Results:

• Calculation of surface binding energies using DFT to construct the corrugation potential.
• Presentation of lateral root-mean-square (rms) deviation of adparticles from binding sites.
• Analysis of equilibrium coverage isotherms and testing of the Arrhenius barrier-hopping model.

Conclusions:

• The off-lattice model provides a more nuanced understanding of adlayer behavior compared to lattice-gas models.
• Simulations offer insights into the static and dynamic properties of bromine adlayers on Ag(100).
• This approach enhances the predictive power for electrochemical deposition processes and surface phenomena.