Adjustable gas adsorption and desorption via a self-shrinking nanoscroll

Abstract

In a gas adsorption–desorption process, gas desorption consumes energy, as well. Hence, the development of gas adsorption–desorption methods and/or adsorbent materials with low-energy consumption for precisely controlling the reversible process is still an open issue. Taking carbon dioxide as an example, this study proposed a carbon nanospring as a unit of an adsorbent model to control the capacity for gas adsorption (CGA), via expanding for adsorption or self-shrinking for desorption by the nanoscroll made from partly hydrogenated graphene ribbon (H-GR). The numerical results obtained from the molecular dynamics approach demonstrate that the CGA of H-GR can be precisely controlled by changing the deformation of H-GR. The adjustable scope of CGA, called capacity for gas desorption, depends on the gas density and the loading speed. However, the ratio of desorption slightly depends on the gas density, which benefits gas capturing in potential application of the present material model.