Hydrogen on graphene under stress: Molecular dissociation and gap opening

Abstract

Density functional calculations are employed to study the molecular dissociation of hydrogen on graphene, the diffusion of chemisorbed atomic species, and the electronic properties of the resulting hydrogen on graphene system. Our results show that applying stress to the graphene substrate can lower the barrier to dissociation of molecular hydrogen by a factor of six, and change the process from endothermic to exothermic. These values for the barrier and the heat of reaction, unlike the zero stress values, are compatible with the time scales observed in experiments. Diffusion, on the other hand, is not greatly modified by stress. We analyse the electronic structure for configurations relevant to molecular dissociation and adsorption of atomic hydrogen on a graphene single layer. An absolute band gap of 0.5 eV is found for the equilibrium optimum configuration for a narrow range of coverages ($\theta \approx 0.25$). This value is in good agreement with experiment [Elias et al., Science {\bf 323}, 610 (2009)].

References in corpus (3)

• Electric Field Effect in Atomically Thin Carbon Films
• Control of graphene's properties by reversible hydrogenation
• Ab-initio calculation of the effect of stress on the chemical activity of graphene

Cited by in corpus (10)

• Prospects for hydrogen storage in graphene
• Limits on gas impermeability of graphene
• Unexpected catalytic activity of nanorippled graphene
• Modulation of the thermodynamic, kinetic and magnetic properties of the hydrogen monomer on graphene by charge doping
• Modeling of hydrogen and hydroxyl group migration on graphene
• Stable antiferromagnetic graphone
• Quantitative Chemistry and the Discrete Geometry of Conformal Atom-Thin Crystals
• Enhanced hydrogen-gas permeation through rippled graphene
• Hydrogen dynamics on defective monolayer graphene
• Suppression of diffusion of hydrogen adatoms on graphene by effective adatom interaction