First‐principles study of oxidized BC2N nanotubes

Abstract

AbstractSpin‐polarized density functional theory and norm conserving fully separable pseudopotentials are used to study the structural and electronic properties of atomic oxygen defects (substitution and adsorbed) as well as the O2 adsorption in (3,3) and (5,0) BC2N nanotubes. For the adsorbed molecules, detailed calculations are performed by introducing the van der Waals interactions through the B97‐D functional proposed by Grimme. The most stable configuration for the adsorbed oxygen atom is in the interstitial site binding with boron and carbon atoms (BOCI configuration), and for the substitutional doping, the most stable configuration occurs when the oxygen substitutes the nitrogen atom (ON). For these two defects, the calculated formation energies are −1.67 and 0.62 eV, respectively. The calculated electronic band structures show that the ON defect leads the system to exhibit a p‐type semiconductor character, whereas the interstitial oxygen atom does not introduce any significant changes in the electronic states near the band gap region. The interaction between the nanotubes and the O2 molecule is investigated by the adsorption of the molecule in the inner and outer surfaces of the nanotubes. The calculated binding energies show that the molecule in the triplet state is physically adsorbed in the inner surface with the molecular axis perpendicular to the nanotube axis. For the molecule in the singlet state, the most stable configuration occurs when the molecule interact with the outer surface and bind (weakly) with a boron atom. We also observe spin transference between the molecule and the tube leading the boron carbonitrides (BCN) nanostructures as candidate to storage and detect the O2 molecules. © 2012 Wiley Periodicals, Inc.