First-principles calculations for the adsorption of water molecules on the Cu(100) surface

TL;DR

This study uses first-principles density-functional theory to investigate water molecule adsorption on Cu(100), revealing preferred bonding sites, diffusion behaviors, and tendencies for water clustering on the surface.

Contribution

It provides detailed computational insights into water adsorption geometry, diffusion rates, and clustering tendencies on Cu(100), aligning with experimental observations.

Findings

Water prefers on-top bonding at T1 site with a tilted geometry.

Rotational diffusion occurs faster than lateral diffusion at low temperatures.

Adsorption energy is lower than sublimation energy, favoring water cluster formation.

Abstract

First-principles density-functional theory and supercell models are employed to calculate the adsorption of water molecules on the Cu(100) surface. In agreement with the experimental observations, the calculations show that a H2O molecule prefers to bond at a one-fold on-top (T1) surface site with a tilted geometry. At low temperatures, rotational diffusion of the molecular axis of the water molecules around the surface normal is predicted to occur at much higher rates than lateral diffusion of the molecules. In addition, the calculated binding energy of an adsorbed water molecule on the surfaces is significantly smaller than the water sublimation energy, indicating a tendency for the formation of water clusters on the Cu(100) surface.