A First-Principles Investigation of Goldene for Enhanced Hydrogen Evolution Reaction

The recent synthesis of Goldene, a 2D sheet of gold exfoliated from $T{i}_{3}Au{C}_2$, offers high specific surface area (~260 $m^2{g}^{-1}$), roughly twice that of fine nanodots (~100 $m^2{g}^{-1}$), and unique electronic properties due to its dense d-orbital. In this work, we investigate the adsorption of single atom catalyst (SAC) of hydrogen atom on pristine goldene (pG), monovacant goldene (vG), and sulfur-functionalized variants (thiol-pG and thiol-vG) using ab initio calculations. The adsorption energy of a single H atom and $\mathrm{\Delta }{G}_H$, determines the efficiency of the Volmer step of the hydrogen evolution reaction (HER) and is a key descriptor for HER activity. We explore various potential sites for H adsorption and its impact on descriptors such as Bader charges, d-band shift and the exchange current density.