Ab initio studies of hydrogen adatoms on bilayer graphene
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Date
Authors
Mapasha, Refilwe Edwin
Ukpong, Aniekan M.
Chetty, Nithaya
Journal Title
Journal ISSN
Volume Title
Publisher
American Physical Society
Abstract
We present a comparative density functional study of the adsorption of hydrogen on bilayer graphene. Six different exchange-correlation functionals are employed to explore the possible configurations of hydrogen ad- sorption at 50% coverage. Using the four variants of the non-local van derWaals density functional, we identify three distinct competing configurations that retain the coupled bilayer structure at 0 K. One of the configurations undergoes a spontaneous transformation from hexagonal to tetrahedral structure, under hydrogenation, with heat of formation ranging between -0.03 eV (vdW-DF) and -0.37 eV (vdW-DFC09x). This configuration has a finite band gap of around 3 eV, whereas all other competing configurations are either semi-metallic or metallic. We also find two unique low-energy competing configurations of decoupled bilayer graphene, and therefore suggest the possibility of graphene exfoliation by hydrogen intercalation.
Description
Keywords
Hydrogen adatoms, Bilayer graphene
Sustainable Development Goals
Citation
Mapasha, RE, Ukpong, AM & Chetty, N 2012, 'Ab initio studies of hydrogen adatoms on bilayer graphene', Physical Review B, vol. 85, no. 20.