How does an external electrical field affect adsorption patterns of thiol and thiolate on the gold substrate ?

TL;DR

This study investigates how external electric fields influence the adsorption behavior of methanethiol and methylthiolate on gold surfaces, revealing changes in adsorption sites, bond orientations, and interaction energies.

Contribution

It provides new insights into the effects of electric fields on thiol and thiolate adsorption patterns and energetics on gold, using computational analysis.

Findings

Electric fields alter sulfur adsorption sites and S-H bond orientations.

The interaction energy for intact methanethiol is higher than for dissociative adsorption.

External electric fields do not induce hydrogen dissociation from sulfur.

Abstract

The responsive behavior of methanethiol and methylthiolate molecules on the Au(111) surface with an applied electrical potential is studied, and it is shown how the sulfur adsorption site, the S-H bond orientation and the interacting energy change with an external electric field strength. The electron charge density corresponding to an electric field minus that obtained in zero field, with zero-field optimal geometry, is calculated to explain the responsive behavior. The interacting energy for the intact methanethiol adsorption is larger than that for the dissociative one, showing that an external electric field can not make the hydrogen dissociate from the sulfur.