Role of the Structure of Graphene Oxide Sheets on the CO₂ Adsorption Properties of Nanocomposites Based on Graphene Oxide and Polyaniline or Fe₃O₄-Nanoparticles

Abstract

New nanocomposites based on graphene oxide with polyaniline (PANI) or Fe3O4 nanoparticles (MG) were synthesized for CO2 capture. To study the effect of graphene oxide structure on the CO2 retention capacity, CO2/N2 selectivity, adsorbent regeneration, and adsorption kinetics, two different graphene oxides were synthesized by oxidation of graphite flakes (GO) and commercial carbon nanofibers (NSGO). CO2 adsorption isotherms at 300 K were evaluated by gravimetric experiments. The results described the CO2 adsorption as reversible physisorption mechanism, where the CO2 adsorption capacity increases linearly with the micropore volume. Results also demonstrate the good CO2/N2 selectivity, recyclability, and fast adsorption kinetics of the materials tested. Differences concerning the adsorption properties of nanocomposites are related to the chemical composition and the size of graphene oxide sheets.