Regensburg 2019 – wissenschaftliches Programm
MM 22.2: Vortrag
Mittwoch, 3. April 2019, 10:30–10:45, H43
Interaction of the H2 molecule with carbon nanostructures: A DFT study — •Dominik Nöger and David Holec — Department of Materials Science, Montanuniversität Leoben, Franz-Josef-Strasse 18, A-8700 Leoben, Austria
On a long path of finding appropriate materials to store hydrogen, graphene and carbon nanotubes have drawn a lot of attention as potential storage materials. Their advantages lie at hand since those materials provide a large surface area (which can be used for physisorption), are cheap compared to metal hydrides, are abundant nearly everywhere, and most importantly, can increase safety to existing storage solutions. The present Density Functional Theory (DFT) study employs Tkatchenko-Schäffler (TS) van-der-Waals correction. The preferred adsorption site for an H2 molecule is the hollow (centre of hexagon) site of planar graphene, with the molecule orientated parallel to graphene. Next, the influence of vacancy and Stone-Wales defects in graphene was studied. Neither of them provides increased adsorption energies for H2. Interestingly, vacancy shows a capability to capture H2 inside the defect in a metastable state; this configuration is unstable both for pure graphene as well as for the Stone-Wales defect. Finally, the impact of different carbon nanotube diameters and geometries (zigzag & armchair configuration) on physisorption energetics and behaviour is presented.