Selective Hydrogen Adsorption in Graphene Rotated Bilayers

Abstract

The absorption energy of atomic hydrogen at rotated graphene bilayers is studied using ab initio methods based on the density functional theory including van der Waals interactions. We find that, due to the surface corrugation induced by the underneath rotated layer and the perturbation of the electronic density of states near the Fermi energy, the atoms with an almost AA stacking are the preferential ones for hydrogen chemisorption. The adsorption energy difference between different atoms can be as large as 80 meV. In addition, we find that, due to the logarithmic van Hove singularities in the electronic density of states at energies close to the Dirac point, the adsorption energy of either electron or hole doped samples is substantially increased. We also find that the adsorption energy increases with the decrease of the rotated angle between the layers.Finally, the large zero point energy of the C-H bond (∼ 0.3eV ) suggests adsorption and desorption of atomic hydrogen and deuterium should behave differently.

Untwisted restacking of two-dimensional metal-organic framework nanosheets for highly selective isomer separations

“…2a–d), which matched well with the widely accepted Zr-BTB structures 30,31 . By checking the stacking fashion between adjacent layers in the HAADF patterns carefully, we first found distinct Moiré patterns 32,33 across the ambient-dried 2-D Zr-BTB-FA samples (Fig. 2a–c and Supplementary Fig.…”

Defect-induced magnetism and Yu-Shiba-Rusinov states in twisted bilayer graphene

“…The highly localized nature of the defect, together with the location of its electronic states in the band diagram is expected to yield a greatly enhanced signal in a scanning tunnel microscope experiment. 23,25 Removing one electron out of the system barely changes the shape of the electronic bands, but empties completely the spin-↑ band, leaving the other partially filled (see Fig.3c). A total magnetic moment of 0.9 µ B is obtained, similarly to the case of monolayer graphene 25 .…”

Electrical band flattening, valley flux, and superconductivity in twisted trilayer graphene

“…From a theoretical point of view, electronic structure calculations of a twisted graphene bilayer conducted with real-space tight-binding models [10] or continuum Dirac descriptions [9] capture the fundamental features of the electronic dispersion. Nevertheless, internal coordinate optimization can quantitatively modify the electronic dispersion [27][28][29][30][31][32][33][34]. Well known examples of this are the growth of AB/BA regions in twisted bilayers [29,35].…”