An ionic liquid (IL) [P-66614][Triz] with a low regeneration temperature was loaded on a graphene nanoplatelet (GNP) and reduced graphene oxide (RGO) to accelerate the CO2 absorption rate. High-resolution transmission electron microscopy (HRTEM) patterns showed that GNP was composed of a regular "honeycomb" lattice, but a regular lattice structure was not observed for RGO as a result of the functional group on it. The CO2 absorption capacity (63.6 mg of CO2/g of IL) and absorption peak rate (22.4 mg of CO2 g(-1) of IL min(-1)) of IL loaded on GNP were increased by 8.2 and 72.3%, respectively, compared to those of neat IL. The supported IL performed better because [P-66614][Triz] was oriented in a favorable dispersion as [P-66614] a result of the negative zeta potential of the GNP surface. In contrast, the CO2 absorption rate of RGO-20% IL (mass ratio of RGO/IL = 4:1) was lower than that of IL, which could be attributed to the hydrogen bond between surface oxygen functional groups and IL. C-13 nuclear magnetic resonance and Mulliken atomic charge calculated by Gaussian were used to support the CO2 absorption mechanism.