{
  "id": "1606.02870",
  "version": "v1",
  "published": "2016-06-09T08:42:48.000Z",
  "updated": "2016-06-09T08:42:48.000Z",
  "title": "Charge transfer and weak bonding between molecular oxygen and graphene zigzag edges at low temperatures",
  "authors": [
    "D. W. Boukhvalov",
    "V. Yu. Osipov",
    "A. I. Shames",
    "K. Takai",
    "T. Hayashi",
    "T. Enoki"
  ],
  "comment": "28 pages, 8 figures, 2 tables, accepted in Carbon journal",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.mtrl-sci",
    "physics.chem-ph",
    "physics.comp-ph"
  ],
  "abstract": "Electron paramagnetic resonance (EPR) study of air-physisorbed defective carbon nano-onions evidences in favor of microwave assisted formation of weakly-bound paramagnetic complexes comprising negatively-charged O2- ions and edge carbon atoms carrying pi-electronic spins. These complexes being located on the graphene edges are stable at low temperatures but irreversibly dissociate at temperatures above 50-60 K. These EPR findings are justified by density functional theory (DFT) calculations demonstrating transfer of an electron from the zigzag edge of graphene-like material to oxygen molecule physisorbed on the graphene sheet edge. This charge transfer causes changing the spin state of the adsorbed oxygen molecule from S = 1 to S = 1/2 one. DFT calculations show significant changes of adsorption energy of oxygen molecule and robustness of the charge transfer to variations of the graphene-like substrate morphology (flat and corrugated mono- and bi-layered graphene) as well as edges passivation. The presence of H- and COOH- terminated edge carbon sites with such corrugated substrate morphology allows formation of ZE-O2- paramagnetic complexes characterized by small (<50 meV) binding energies and also explains their irreversible dissociation as revealed by EPR.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-06-09T08:42:48.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "charge transfer",
      "graphene zigzag edges",
      "low temperatures",
      "molecular oxygen",
      "carbon atoms carrying pi-electronic"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 28,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}