Berlin 2015 – scientific programme
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O: Fachverband Oberflächenphysik
O 21: Graphene: Growth & Intercalation
O 21.8: Talk
Tuesday, March 17, 2015, 12:15–12:30, MA 041
Reversible Hydrogenation of Graphene on Ni(111) - Synthesis of ’Graphone’ — •Julian Gebhardt1, Wei Zhao2, Florian Späth2, Karin Gotterbarm2, Christoph Gleichweit2, Hans-Peter Steinrück2, and Andreas Görling1 — 1Lehrstuhl für Theoretische Chemie, Universität Erlangen-Nürnberg, 91058 Erlangen, Germany — 2Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
Understanding the adsorption and reaction between hydrogen and graphene is of fundamental importance for developing graphene-based concepts for hydrogen storage and for the chemical functionalization of graphene by hydrogenation. Recently, theoretical studies of single-sided hydrogenated graphene, so called graphone, predicted it to be a promising semiconductor for applications in graphene-based electronics. Here, we report on the synthesis of graphone bound to a Ni(111) surface. We investigate the formation process by X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption (TPD), and density-functional theory calculations, showing that the hydrogenation of graphene with atomic hydrogen indeed leads to graphone, i.e., a hydrogen coverage of 1 ML (4.2 wt%). In addition, the dehydrogenation of graphone was shown to be possible by XPS and TPD measurements. The complex desorption process was attributed to coverage-dependent changes in the activation energies for the associative desorption of hydrogen as molecular H2.