Confinement of $$\hbox {CO}_{2}$$ inside carbon nanotubes

Abstract

Abstract We propose a preliminary study based on molecular dynamics calculations to investigate the adsorption of pure $$\hbox {CO}_{2}$$ CO 2 on flexible single-walled carbon nanotubes (SWCNTs) of different sizes. The adsorption capacities of SWCNTs were simulated and the effect of chirality and diameter of SWCNTs was assessed, to check them as sizable carbon structured materials suitable for $$\hbox {CO}_{2}$$ CO 2 confinement and storage. The potential energy surfaces, describing the intermolecular interactions involving $$\hbox {CO}_{2}$$ CO 2 -SWCNT and $$\hbox {CO}_{2}$$ CO 2 -$$\hbox {CO}_2$$ CO 2 pairs, have been described specifically by adopting the improved lennard jones model potential. The intramolecular interactions within the SWCNT were considered explicitly since they are responsible for out-of-plane movements of carbon atoms and the flexibility of nanotubes. These well-formulated potentials are well capable of defining $$\hbox {CO}_{2}$$ CO 2 confinement through physisorption and guarantee a quantitative description and realistic results for the dynamics of the interactions. The flexible SWCNTs can adsorb up to 35 wt% at 273 K, a property that makes them potentially versatile materials competitive with other carbon-derived adsorbents to cope with $$\hbox {CO}_{2}$$ CO 2 gas emission. Graphic abstract