Absorption of hydrogen sulfide and carbon dioxide in exfoliated graphene oxide (EGO)-water and synthesized silica (SS)-water nanofluids in a bubble column was investigated. Oxygen, group functionalities and silanol groups were detected on the surface of EGO and SS nanoparticles, respectively. Due to the adsorption of H2S by these functionalities in EGO and SS nanoparticles, the mass transfer coefficient, k(L), increased more than 500% and 200% relative to the based fluid, respectively. The EGO-water nanofluid significantly absorbs H2S while CO2 absorption is diminished to zero in nanoparticle mass fractions higher than 0.02 wt %, because oxygen groups on the EGO surface attract H2S but repel CO2 molecules. However, SS nanoparticles attract both CO2 and H2S due to hydrogen bonding between gas molecules and hydrogen atoms in the silanol groups.