First‐principles study of oxidized BC₂N nanotubes

Abstract

Spin-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 O 2 adsorption in (3,3) and (5,0) BC 2 N 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 (BAOAC I configuration), and for the substitutional doping, the most stable configuration occurs when the oxygen substitutes the nitrogen atom (O N ). For these two defects, the calculated formation energies are À1.67 and 0.62 eV, respectively. The calculated electronic band structures show that the O N 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 O 2 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 O 2 molecules.

First principles study of electronic and structural properties of single walled zigzag boron nitride nanotubes doped with the elements of group IV

“…However, bond lengths pertaining to impurity substitution at B site are shorter than impurities that are substituted at N site due to higher electronegativity of nitrogen than boron. The only exception is carbon: calculated bond lengths show that C-N bond length is shorter than that of pristine BNNT which could be understood by the fact that atomic radius of C (0.76 Å) is closer to N (0.72 Å) than B(0.84 Å) [40]. These results are consistent with bond angles listed in table 1.…”

“…The formation energy for X doped is calculated using total energy calculations as the following equation [15,40]. [ ] T E NT is the total energy of the pristine system.…”

“…The formation energy for X doped is calculated using total energy calculations as the following equation [15,40].…”

Nanoporous Graphene and H-BN from BCN Precursors: First-Principles Calculations

“…Therefore, the study of possible sites for oxygen adsorption in BCN might be a possible route to investigate the kinetics of pore formation. For example, quantum chemical calculations 41 indicate that in BCN nanotubes the oxygen atom might tend to adsorb between carbon and boron atoms.…”