Preparation of three-dimensional graphene oxide-polyethylenimine porous materials as dye and gas adsorbents.

We report a facile method for the fabrication of three-dimensional (3D) porous materials via the interaction between graphene oxide (GO) sheets and polyethylenimine (PEI) with high amine density at room temperature under atmospheric pressure without stirring. The structural and physical properties of GO-PEI porous materials (GEPMs) are investigated by scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and nitrogen adsorption-desorption measurement and their chemical properties are analyzed by X-ray photoelectron spectroscopy, infrared spectroscopy, and Raman spectroscopy. GEPMs possess low density and hierarchical morphology with large specific surface area, and big pore volume. Furthermore, the as-prepared 3D porous materials show an excellent adsorption capacity for acidic dyes on the basis of the pore-rich and amine-rich graphene structure. GEPMs exhibit an extremely high adsorption capacity for amaranth (800 mg g(-1)), which are superior to other carbon materials. In addition, GEPMs also exhibit good adsorption capacity for carbon dioxide (11.2 wt % at 1.0 bar and 273 K).