A novel easily collected material with carbon dioxide absorption capability was constructed by grafting polyethylene polyamine onto magnetic Fe3O4 nanoparticles. The structures and morphologies of the Fe3O4 nanoparticles encapsulated by polyethylene polyamine were identified by FT-IR and TEM. After Fe3O4 nanoparticles were functionalized by amine, the as-prepared material could be dispersed in water stably. Moreover, such material presented superparamagnetic property and then could be collected easily in a magnetic field, which could provide a facile and energy-saving process for CO2 capture. Absorption studies indicated that high CO2 absorption capacity, high CO2 absorption rates, and good selectivity of the nano-absorbents were achieved. The nano-absorbents also showed good reversibility and stability during cyclic absorption-regeneration tests (10 cycles). (C) 2012 Elsevier B.V. All rights reserved.