Hydrogen storage capacity of Ti-doped boron-nitride andB∕Be-substituted carbon nanotubes

Abstract

We investigate the hydrogen absorption capacity of two tubular structures, namely, B / Be-substituted singlewall carbon nanotube ͑SWNT͒ and Ti covered single-wall boron nitride nanotube ͑SWBNT͒ using firstprinciples plane wave method. The interaction of H 2 molecules with the outer surface of bare SWBNT, which is normally very weak, can be significantly enhanced upon functionalization by Ti atoms. Each Ti atom adsorbed on SWBNT can bind up to four H 2 molecules with an average binding energy suitable for room temperature storage. While the substitution process of Be atom on SWNT is endothermic, the substituted Be strengthens the interaction between tube surface and H 2 to hold one H 2 molecule.

Dispersion-corrected density functional theory comparison of hydrogen adsorption on boron-nitride and carbon nanotubes

“…28,30 Conversely the binding energy of molecular H 2 physisorption are typically an order of magnitude smaller than the target: 20-40 meV has been reported for armchair BNNT calculated using hybrid functionals; 28 50 meV has been reported using ultrasoft pseudopotentials with a distance of approximately 3.5 Å from the surface of the nanotube. 33 A maximum of 90 meV for zigzag BNNT where hydrogen is about 3.1 Å above the surface has been reported. 28 Metal doping of BNNTs has been suggested to provide an intermediate regime, including Ti, 33 Pt, 34,35 and other transition metal 36 doping.…”

“…33 A maximum of 90 meV for zigzag BNNT where hydrogen is about 3.1 Å above the surface has been reported. 28 Metal doping of BNNTs has been suggested to provide an intermediate regime, including Ti, 33 Pt, 34,35 and other transition metal 36 doping. Binding energies of hydrogen molecules close to the metal site of several tenths of one meV have been predicted.…”

“…4,[28][29][30][31][32][33] Similar to CNTs the binding energies for atomic H chemisorption on BNNTs are found to be an order of magnitude higher than the target: in the range of several eV. 28,30 Conversely the binding energy of molecular H 2 physisorption are typically an order of magnitude smaller than the target: 20-40 meV has been reported for armchair BNNT calculated using hybrid functionals; 28 50 meV has been reported using ultrasoft pseudopotentials with a distance of approximately 3.5 Å from the surface of the nanotube.…”

Molar Binding Energy of Zigzag and Armchair Single-Walled Boron Nitride Nanotubes

“…Pretreating of these systems so as to partially remove nitrogen should enhance H 2 adsorption properties. The hydrogen absorption capacity of Ti-covered single-walled BN nanotube was investigated using first principles plane-wave (PW) method [37]. The weak interaction of H 2 molecules with the outer surface of bare nanotube can be significantly enhanced upon functionalization by Ti atoms: each Ti atom adsorbed on tube can bind up to four H 2 molecules with average binding energy suitable for room temperature storage.…”

Geometric and Spectroscopic Properties of Carbon Nanotubes and Boron Nitride Nanotubes

“…For reason, BNNTs with the small diameter were suggested as an aspirant for a synthetic aquaporin-1 water channel [57]. A variety of subjects of BNNTs have been investigated by theoretical methods, including hydrogen storage [60,61,62,63,64,65,66], magnetism [67,68,69,70,71,72,73], phonon characteristics [74,75,76], stability [77,78,79], molecular dynamics [80,81,82,83], field-electron emission [84], scanning tunneling microscopy simulation [85], electron transport [86], symmetry breaking [87], work function [88], spin-splitting [89] and quantum computing [90,91]. …”