Adsorption of the astatine species on gold surface: a relativistic density functional theory study

TL;DR

This study uses relativistic density functional theory to investigate how astatine species adsorb on gold surfaces, providing insights relevant for experiments with superheavy elements like tennessine and nihonium.

Contribution

It offers the first-principles calculation of adsorption energies of astatine and its hydroxide on gold surfaces, aiding interpretation of experimental data involving superheavy elements.

Findings

Adsorption energy of At on gold: 130 ± 10 kJ/mol

Adsorption energy of AtOH on gold: 90 ± 10 kJ/mol

Relativistic DFT effectively models superheavy element interactions.

Abstract

We report on first-principle based studies of the adsorption interaction of astatine species on a gold surface. These studies are aimed primarily at the support and interpretation of gas chromatographic experiments with Superheavy Elements, tennessine (Ts, $Z=117$) as the heavier homologue of At and possibly nihonium (Nh, $Z=113$) as its pseudo-homologue. The adsorption energies of elemental astatine or the corresponding monohydroxide on a stable gold (111) surface are estimated using gold clusters with up to 69 atoms in order to simulate the adsorption site. To simulate the electronic structure of $\rm At-Au_n$ and $\rm AtOH-Au_n$ complexes, we combine accurate shape-consistent relativistic pseudopotentials and non-collinear two-component relativistic density functional theory. The predicted adsorption energies for At and AtOH on gold are $\rm 130 \pm 10$ kJ/mol and $\rm 90 \pm 10$ kJ/mol, respectively.