2008/08/08 by Simone Casolo, Ole Martin Løvvik, Ole Martin Lovvik +2 · 2 citations
Materials Science · Physics and Astronomy · #Adsorption #Atom (system on chip) #Binding energy #Boron and Carbon Nanomaterials Research #Density functional theory #Graphene #Graphene research and applications #Graphite #Hydrogen #Hydrogen Storage and Materials #Hydrogen atom #Range (aeronautics) #cond-mat.mtrl-sci
paper · pdf · doi:10.1063/1.3072333
12 pages, 8 figures and 4 tables
arxiv created 2008/08/08 · openalex publication_date 2009/02/04 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Adsorption of hydrogen atoms on a single graphite sheet (graphene) has been investigated by first-principles electronic structure means, employing plane-wave based periodic density functional theory. A 5 x 5 surface unit cell has been adopted to study single and multiple adsorptions of H atoms. Binding and barrier energies for sequential sticking have been computed for a number of configurations involving adsorption on top of carbon atoms. We find that binding energies per atom range from approximately 0.8 to approximately 1.9 eV, with barriers to sticking in the range 0.0-0.15 eV. In addition, depending on the number and location of adsorbed hydrogen atoms, we find that magnetic structures may form in which spin density localizes on a square root(3) x square root(3)R30 degrees sublattice and that binding (barrier) energies for sequential adsorption increase (decrease) linearly with the site-integrated magnetization. These results can be rationalized with the help of the valence-bond resonance theory of planar pi conjugated systems and suggest that preferential sticking due to barrierless adsorption is limited to formation of hydrogen pairs.