Theoretical study of the structural and electronic properties of novel stanene-based buckled nanotubes and their adsorption behaviors

摘要

Graphical abstractDisplay OmittedHighlights•DFT calculations were carried out to investigate the structural and electronic properties of stanene based nanotubes.•The (4, 4) a-Sn-NT only has two indirect band gaps of 0.45 eV between V2and C1and V2and C2 .•(5, 5) NT has both direct band gap between V1and C2, and indirect band gap between V2and C2.•(4, 0) and (7, 0) NTs are metallic, while others with a direct band gap at ᴦ point are semiconductors.•In (6, 6) a-SnNT, the orbitals corresponding to CBM, was localized on inner Sn atoms and smeared in spaces between outer Sn atoms.AbstractDensity functional theory calculations were performed to investigate the geometrical, electronic and adsorption properties of stanene based nanotubes in order to fully exploit the gas sensing capability of these nanotubes. The strain energy, structural parameters and electronic properties of stanene-based nanotubes with armchair and zigzag chirality with various diameters were examined in detail. The results show that, these nanotubes have a buckled structure, in which the tin atoms were arranged in chair-like honeycomb configuration. Calculated strain energy for considered nanotubes are relatively small compared to some other nanotubes pointed to flexibility of stanene mono layer. It was found that the strain energies for (4, 0), (5, 0) and (6, 0) nanotubes have negative values, indicating their stability with respect to stanene nanosheet. The band structure calculations reveal that the armchair nanotubes are semiconductors with two maximums with nearly same energies in valence band. However, the zigzag ones show both conductor and semiconductor behaviors by direct band gap in ᴦ point. Also the spatial distribution of molecular orbitals in valence band maximums and conduction band minimums were presented and discussed. Moreover, the adsorption behaviors of (6, 6) and (8, 8) nanotubes as chemical O3detection device were investigated in detail. We found that O3molecule dissociates into O2over the considered nanotubes, being an effective strategy to help in the reduction of the concentration of these harmful pollutants in the environment. The results also suggest that O3dissociation over the (6, 6) nanotube is more favorable in energy than that on the (8, 8) nanotube. The results present a great potential of stanene based nanotube for application as a highly sensitive ozone gas sensor.