Balance between physical and chemical interactions of second-row diatomic molecules with graphene sheet

DFT Calculations of Hydrogen Adsorption inside Single‐Walled Carbon Nanotubes

“…As a whole, one may observe the increase in E b on going from (3,3) to (5,5) SWCNTs and the following decrease on going from (5,5) to (8,8) SWCNTs, with the maximal E b of −0.195 (parallel orientation) and −0.199 eV (perpendicular orientation) ( Table 1). It can be explained by the very small diameters of the (3,3) and (4,4) SWCNTs which complicate the introduction of hydrogen.…”

“…is functional has been demonstrated to be reliable and commonly used in the studies of adsorption phenomena [34,35]. We consider various armchair nanotubes as models of (n,n) SWCNTs, n � 3-8. e following models of SWCNTs are used: C 48 H 12 (3,3), C 64 H 16 (4,4), C 80 H 20 (5,5), C 96 H 24 (6,6), C 112 H 28 (7,7), and C 138 H 32 (8,8). It was earlier predicted that the (2,2) armchair SWCNT is the carbon nanotube with the smallest possible diameter of 3Å [36].…”

“…e larger tubes provide more space for H 2 molecules to introduce into and adsorb onto the internal walls of SWCNTs. Besides this, (5,5) SWCNT represents the best diameter/number of neighbor carbon atoms ratio. Indeed, the comprehensive work of Okamoto and Miyamoto [39] showed that the E b values depend significantly on the carbon nanotubes' curvature or, in other words, on the number of neighbor carbon atoms.…”

“…e methods of the scalable synthesis and separation of SWCNTs can be found elsewhere [40,41]. Compared with flat graphene-based materials for H 2 storage, the (5,5) and (6,6) SWCNTs have the improved E b values.…”

“…In recent years, numerous studies on the potential applications of single-walled carbon nanotubes (SWCNTs) [1] in various fields including the development of novel organic electronic materials, chemical sensors, and vehicles for organ-specific drug delivery and other therapeutic processes have been carried out [2][3][4][5][6][7][8][9][10]. Noncovalent interactions of small molecules and SWCNTs are pivotal to many of these applications [11][12][13].…”