Reversible CO2 adsorption by an activated nitrogen doped graphene/polyaniline material

Abstract

For effective adsorption of carbon dioxide (CO2), we investigate a porous N functionalized graphene adsorbent produced by the chemical activation of a reduced graphene oxide/polyaniline composite. The N-doped graphene composite is microporous with a maximum BET surface area of 1336 m2 g−1. It shows a highly reversible maximum CO2 storage capacity of 2.7 mmol g−1 at 298 K and 1 atm (5.8 mmol g−1 at 273 K and 1 atm). The N-doped graphene shows good stability during recycling with only an initial decrease of 10% (3–2.7 mmol g−1) in adsorption capacity before attaining a cycling equilibrium. The adsorbance capacity is correlated with N content × pore volume or N content × surface area. Given that there is no proper correlation parameter, these factors can be used to increase the CO2 adsorption capacity of N-doped graphene materials for practical utility. The as synthesized material also displays selectivity towards CO2 adsorption compared to H2, N2, Ar or CH4. The as formed material shows that graphene can be uniformly N-doped using the presented synthetic method.