Oxidation of monovacancies in graphene by oxygen molecules

Abstract

CitationKaloni TP, Cheng YC, Faccio R, Schwingenschlögl U We study the oxidation of monovacancies in graphene by oxygen molecules using first principles calculations. In particular, we address the local magnetic moments which develop at monovacancies and show that they remain intact when a molecule is adsorbed such that the dangling carbon bonds are not fully saturated. However, the lowest energy configuration does not maintain dangling bonds and is found to be semiconducting. Our data can explain the experimentally observed behavior of graphene under exposure to an oxygen plasma.

Oxidation of graphene in ozone under ultraviolet light

“…This is consistent with previous theoretical calculations. 10,13 The pseudogaps visible in Figs. 3(a)-3(c) and 3(e) amount to about 0.2 eV, suggesting that the Dirac cone is maintained but a small band gap is opened for the atoms around the defect.…”

“…A detailed analysis of the resulting configuration can be found in Ref. 13. Continuation of the oxidation process can lead to the release of another CO molecule, see Fig.…”

“…9,14 In addition, the fact that the energy gap can be tuned in a wide range from 0 to 4 eV demonstrates that functionalization of graphene by oxidation has serious effects on the electronic states. 10,13 However, there exists little knowledge about the oxidation process itself.…”

“…Recently, various studies have dealt with the oxidation of graphene by ozone and O ions. [5][6][7][8][9][10][11][12][13][14] In an ozone generator, C atoms are removed from the graphene lattice and vacancies are formed. The morphology of exposed singlelayer and multilayer graphene samples reflects a highly disordered nature, which varies with the thickness.…”

Strong Coupling between Nanofluidic Transport and Interfacial Chemistry: How Defect Reactivity Controls Liquid–Solid Friction through Hydrogen Bonding

“…[25][26][27][28] Defects can even be desirable for nanofluidic energy conversion, since the efficiency of the conversion is directly related to the surface charge, 11,20,29 usually found in the form of charged defects. Defects can be reactive, [30][31][32][33] and although previous work has investigated how reactive defects modify the structure of the water-solid interface, 34-37 the consequences of this reactivity on nanofluidic transport remains an open question. Indeed, up to now only the direct, mechanical effect of defects on liquid-solid friction has been explored using simulation approaches based on force field molecular dynamics.…”