Hydrogenated grain boundaries in graphene

TL;DR

This study uses first principles calculations to explore how hydrogen atoms interact with grain boundary defects in graphene, revealing stable adsorption sites and potential for localized graphane formation.

Contribution

It provides new insights into hydrogen adsorption preferences at grain boundaries in graphene and suggests these defects can serve as nucleation sites for graphane strip formation.

Findings

Hydrogen prefers to adsorb at grain boundary defects.

Two hydrogen atoms forming a graphane unit are more stable at defect regions.

Defects may act as nucleation sites for graphane in graphene.

Abstract

We have investigated by means of first principles calculations the structural and electronic properties of hydrogenated graphene structures with distinct grain boundary defects. Our total energy results reveal that the adsorption of a single H is more stable at grain boundary defect. The electronic structure of the grains boundaries upon hydrogen adsorption have been examined. Further total energy calculations indicate that the adsorption of two H on two neighbor carbons, forming a basic unit of graphane, is more stable at the defect region. Therefore, we expect that these extended defects would work as a nucleation region for the formation of a narrow graphane strip embedded in graphene region.