Regensburg 2019 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 9: Graphene I: Structure and Growth (joint session O/TT)
TT 9.7: Vortrag
Montag, 1. April 2019, 12:15–12:30, H24
The role of the curvature of graphitic materials in the oxygen adoption reaction — Jakob Hauns, Julian Wüst, Jürgen Weippert, Regina Fischer, Frank Hennrich, Dmitry Strelnikov, •Artur Böttcher, and Manfred M. Kappes — Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany
The capability of graphitic materials to bind atomic oxygen has been studied under ultrahigh vacuum conditions by monitoring the oxygen-induced evolution of the XPS-O1s, -C1s and the valence band states, UPS-VB. Three groups of solid films were investigated: HOPG (planar graphene sheet), felts of metallicity-sorted single walled carbon nanotubes S-, M-SWCNTs and solid C60 films. The monodispersed materials chosen here differ by the curvature C of the graphene layers. In order to quantify the role of strained C-C-C bonds in the oxidation pathway exactly the same oxidation procedure has been applied to all graphitic materials. The VB-DOS profiles measured for oxidized films differ clearly by their oxygen-derived bands and the work functions. The evolution of the XPS-O1s and -C1s states indicate that whereas the oxidation of planar graphene sheets proceeds via epoxy species [1], ether functionalities dominate the oxidative scenario of the curved surfaces of SWCNT and C60. The yield for the initial oxygen-adoption reaction for all curved surfaces is significantly higher than that measured for planar graphene sheets. This finding stresses the unique role of the strained -C-C-C- bonds which facilitate the formation of ether functionalities. [1] A. Barinov, et al. J. Phys. Chem. C 2009, 113, 9009.