▎ 摘　　要

Amine-functionalized solid adsorbents show promising potential for the capture of CO2, a harmful greenhouse gas which is regarded as the major cause of global warming. In this study, three amine functionalities of triethylenetetramine (TETA), pentaethylenehexamine (PEHA), and meta-phenylenediamine (MPD) were separately anchored to the GO surface. The analyzing methods, including Fourier transform infrared spectroscopy (FTIR), CHNS elemental analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and N-2 adsorption-desorption were used to study the characteristics of the synthesized GO series. The equilibrium adsorption of CO2 on GO and amine-functionalized GO (GO-NH2) were experimentally measured at 298, 308, and 318 K and pressure range of 0-14 bar. The CO2 uptake was strikingly improved from 0.39 mmol/g for GO to 0.61, 0.74, and 0.91 mmol/g for GO-PEHA, GO-TETA, and GO-MPD adsorbents at 298 K and 1 bar, respectively. The prediction of the selectivity of the adsorbents based on the ideal adsorbed solution theory (IAST) exhibited the excellent selectivity of the adsorbents, in particular for GO/MPD around 21.21 for the selective capture of CO2 over N-2 under ambient conditions. The isosteric heats of adsorption indicated the physisorption of CO2 on amine-modified GO samples and also its precursor. The high CO2/N-2 selectivity obtained in this study and cyclic operation tests prove that GO-NH2 samples can be applied as an impressive adsorbent to capture CO2 from flue gas.