Preparation and characterization of an amine-modified graphene aerogel for enhanced carbon dioxide adsorption

A 3D porous graphene aerogel (GA) was prepared via one-step hydrothermal method and freeze-drying technology, in which organic amine reagents were used as cross-linker to combine the graphene oxide (GO) sheets. With abundant amino groups, the organic amine reagents also acted as adsorption sites to improve CO 2 adsorption capacity. Morphology, pore structure and surface chemical structure of the as-prepared materials were characterized by SEM, FTIR, XRD, Raman, TG, N 2 adsorption–desorption. CO 2 adsorption performance was evaluated by dynamic adsorption experiments in a fixed-bed column. Aminated by tetraethylenepentamine (TEPA), the prepared 3D graphene aerogel (TEPA-GA-3–1) achieved a CO 2 adsorption capacity as high as 2.27 mmol g −1 at 25 °C, 0.1 bar, which was attributed to its developed porous structure and high amino density. Further, the existence of water could improve the CO 2 adsorption amount because H 2 O directly participates the reaction of CO 2 with amine to form bicarbonates. The prepared GA adsorbent also exhibited good stability after six adsorption–desorption cycles. The above result suggests that amine-modified graphene aerogel has a potential application for CO 2 capture from flue gas. Graphical abstract