A new method for enhancing the mass transfer coefficient in the gas absorption process is reported. CO2 absorption experiments were carried out in a wetted-wall column using different aqueous nanofluids as the solvent. The mass transfer characteristics were found to increase by applying Al2O3/water nanofluid. The mass transfer coefficient decreased with TiO2/water nanofluid. In the case of Fe3O4/water nanofluid, the mass transfer rate was enhanced by increasing the nanoparticle volume fraction, but the mass transfer coefficient was lower than that obtained with water for all experimental conditions studied. Finally, applying a downward magnetic field resulted in higher mass flux and mass transfer coefficient in comparison with experiments without a magnetic field.