A novel dual amino-functionalized ionic liquid, 1, 3-di (2'-aminoethyl)-2-methylimidazolium bromide (DAIL), was synthesized and investigated as a potential absorbent for CO2 capture. CO2 absorption behavior on pressure, temperature and concentrations of DAIL in aqueous solution were studied, and the absorption mechanism was investigated by spectroscopic methods and DFT calculations. The CO2 capture capacity of 18.5 wt % and good thermal stability (T-d = 521.6 K) make DAIL a, good candidate for industrial applications for CO2 capture.