Charge-modulated/electric-field controlled reversible CO2/H2 capture and storage on metal-free N-doped penta-graphene

Abstract

Abstract Development of advanced materials for the capture and separation of CO2 from the gas mixture is necessary to mitigate the greenhouse effect. In this study, we perform density functional theory computations with long-range dispersion correction to study CO2, H2, CH4 and N2 on the N-doped penta-graphene (PG) sheet under different charge-induced density and applied external electric field. We reveal that the CO2 capture/release process is reversible that can be simply controlled by switching on/off the charged states and electric field of the N-doped PG. The CO2 adsorption is weak on the neutral state of N-doped PG sheet, whereas the adsorption of CO2 can be intensely enhanced under the action of charge-induced density and external electric field. Comparing with the CO2 adsorption, the adsorption species of H2, CH4 and N2 are strikingly weaker signifying that the N-doped PG sheet for CO2 separation from its mixtures with H2, CH4 and/or N2 exhibits efficiently high selectivity by a charge/electric field-controlled. These results might afford new awareness in searching for materials with remarkably high CO2 capture capacity.