We study the binding of molecular oxygen to a （5, 0） single walled SiC nanotube, by means of density functional calculations. The center of a hexagon of silicon and carbon atoms in sites on SiCNT surfaces is the mos...We study the binding of molecular oxygen to a （5, 0） single walled SiC nanotube, by means of density functional calculations. The center of a hexagon of silicon and carbon atoms in sites on SiCNT surfaces is the most stable adsorption site for 02 molecule, with a binding energy of -38.22 eV and an average Si-O binding distance of 1.698 A. We have also tested the stability of the 02-adsorbed SiCNT/CNT with ab initio molecular dynamics simulation which have been carried out at room temperature. Furthermore, the adsorption of 02 on the single walled carbon nanotubes has been investigated. Our first-principles calculations predict that the 02 adsorptive capability of silicon carbide nanotubes is much better than that of carbon nanotubes. This might have potential for gas detection and energy storage.展开更多
We study the adsorption of a methanol molecule on single-walled carbon nanotubes （SWCNTs） with various diameters and chiral angles by using the density functional theory based calculations. We find that methanol pre...We study the adsorption of a methanol molecule on single-walled carbon nanotubes （SWCNTs） with various diameters and chiral angles by using the density functional theory based calculations. We find that methanol prefers to be adsorbed physically on the exterior surface of chiral nanotubes in comparison to the armchair and zigzag tubes with binding energy of about -2.76 kcal/mol, which is consistent with recent experimental and theoretical investigation results. We further consider the adsorption of methanol on the exterior surface and edge site of functionalized SWCNTs. The obtained results indicate that the binding energy of methanol is significantly increased for adsorption on the sidewall of functionalized nanotubes. It is also found that the adsorption of methanol at the edge site of both functionalized and pristine SWCNT is remarkably different （chemisoption process） in comparison to the exterior sidewall of the tubes. Furthermore, the electronic structures and Mulliken charge population of the considered complexes at their ground state are discussed within the context.展开更多
We investigate the interaction of single-walled carbon nanotubes （SWCNTs） and methane molecule from the first principles. Adsorption energies are calculated, and methane affinities for the typical semiconducting and...We investigate the interaction of single-walled carbon nanotubes （SWCNTs） and methane molecule from the first principles. Adsorption energies are calculated, and methane affinities for the typical semiconducting and metallic nanotubes are compared. We also discuss role of the structural defects and nanotube curvature on the adsorption capability of the SWCNTs. We could observe larger adsorption energies for the metallic CNTs in comparison with the semiconducting CNTs. The obtained results for the zig zag nanotubes with various diameters reveal that the adsorption energy is higher for nanotubes with larger diameters. For defected tubes the adsorption energies are calculated for various configurations such as methane molecule approaching to the defect sites pentagon, hexagon, and heptagon in the tube surface. The results show that the introduce defects have an important contribution to the adsorption mechanism of the methane on SWNTs.展开更多
文摘We study the binding of molecular oxygen to a （5, 0） single walled SiC nanotube, by means of density functional calculations. The center of a hexagon of silicon and carbon atoms in sites on SiCNT surfaces is the most stable adsorption site for 02 molecule, with a binding energy of -38.22 eV and an average Si-O binding distance of 1.698 A. We have also tested the stability of the 02-adsorbed SiCNT/CNT with ab initio molecular dynamics simulation which have been carried out at room temperature. Furthermore, the adsorption of 02 on the single walled carbon nanotubes has been investigated. Our first-principles calculations predict that the 02 adsorptive capability of silicon carbide nanotubes is much better than that of carbon nanotubes. This might have potential for gas detection and energy storage.
文摘We study the adsorption of a methanol molecule on single-walled carbon nanotubes （SWCNTs） with various diameters and chiral angles by using the density functional theory based calculations. We find that methanol prefers to be adsorbed physically on the exterior surface of chiral nanotubes in comparison to the armchair and zigzag tubes with binding energy of about -2.76 kcal/mol, which is consistent with recent experimental and theoretical investigation results. We further consider the adsorption of methanol on the exterior surface and edge site of functionalized SWCNTs. The obtained results indicate that the binding energy of methanol is significantly increased for adsorption on the sidewall of functionalized nanotubes. It is also found that the adsorption of methanol at the edge site of both functionalized and pristine SWCNT is remarkably different （chemisoption process） in comparison to the exterior sidewall of the tubes. Furthermore, the electronic structures and Mulliken charge population of the considered complexes at their ground state are discussed within the context.
文摘We investigate the interaction of single-walled carbon nanotubes （SWCNTs） and methane molecule from the first principles. Adsorption energies are calculated, and methane affinities for the typical semiconducting and metallic nanotubes are compared. We also discuss role of the structural defects and nanotube curvature on the adsorption capability of the SWCNTs. We could observe larger adsorption energies for the metallic CNTs in comparison with the semiconducting CNTs. The obtained results for the zig zag nanotubes with various diameters reveal that the adsorption energy is higher for nanotubes with larger diameters. For defected tubes the adsorption energies are calculated for various configurations such as methane molecule approaching to the defect sites pentagon, hexagon, and heptagon in the tube surface. The results show that the introduce defects have an important contribution to the adsorption mechanism of the methane on SWNTs.
