▎ 摘　　要

Highly porous foams based on graphene oxide functionalized with polyethylenimine are generated and used with unprecedented efficiency for adsorbing heavy metal ions. A multiscale analysis of the GO-BPEI nanocomposite provided evidence for the covalent grafting of BPEI on GO and the formation of low crystalline porous foams. The uptake experiments revealed that the GO-BPEI's adsorption of toxic cations is strongly dependent on the pH in range from 2 to 10, as a result of the different interactions at the supramolecular level between the metal ions and the GO-BPEI foam. The maximum uptake capacities for Cu(ii), Cd(ii) and Pb(ii) are achieved at pH = 5 and exhibit values as high as 1096, 2051 and 3390 mg g(-1), respectively, being ca. over 20 times greater than standard sorbents like activated carbon. The GO-BPEI composite can be easily regenerated as proven by performing adsorption cycles. Also, the thermodynamic parameters including standard Gibbs free energy (G(o)), the enthalpy change (H-o) and entropy change (S-o) revealed the exothermic and spontaneous nature of the adsorption process.