Graphene to Graphane: The Role of H Frustration in Lattice Contraction

TL;DR

This study investigates how hydrogen atom frustration affects the lattice contraction in graphane, revealing that H frustration significantly influences structural properties and the graphene-to-graphane conversion process.

Contribution

It provides the first detailed analysis of H frustration's impact on graphane's lattice contraction using ab initio and molecular dynamics methods.

Findings

H frustration causes notable lattice contraction in graphane.

H frustration plays a key role in the graphene to graphane transformation.

Dynamical processes of hydrogenation are characterized.

Abstract

Graphane is a two-dimensional system consisting of a single planar layer of fully saturated (sp$^3$ hybridization) carbon atoms with H atoms attached to them in an alternating pattern (up and down with relation to the plane defined by the carbon atoms). Stable graphane structures were theoretically predicted to exist some years ago and just experimentally realized through hydrogenation of graphene membranes. In this work we have investigated using \textit{ab initio} and reactive molecular dynamics the role of H frustration (breaking the H atoms up and down alternating pattern) in graphane-like structures. Our results show that H frustration significantly contributes to lattice contraction. The dynamical aspects of converting graphene to graphane is also addressed.