Judicious fabrication of bifunctionalized graphene oxide/MnFeO magnetic nanohybrids for enhanced removal of Pb(II) from water.

Novel ternary nanohybrids, bifunctionalized graphene oxide/MnFeO magnetic nanoparticles (PEHA-Phos-GO/MnFeO), were prepared by a facile method and applied for the removal of Pb(II) from aqueous solution. Attributing to the numerous amino and phosphate groups on the bifunctionalized GO nanosheets as well as the magnetic nanoparticles of MnFeO, PEHA-Phos-GO/MnFeO demonstrated high removal efficiency of Pb(II) and rapid magnetic separation. The 366.4 mg/g maximum adsorption capacity of Pb(II) on PEHA-Phos-GO/MnFeO was obtained at the optimal adsorption pH of 5.5, much higher than that on GO (212.1 mg/g). The kinetics and isotherm data indicated that the adsorption processes can be well described by the pseudo-second-order kinetics and the Langmuir model. For the adsorption of Pb(II) on PEHA-Phos-GO/MnFeO, thermodynamic studies revealed the endothermic nature of the spontaneous adsorption process. The exhibited adsorption capacity, easy magnetic separation and reusability make the PEHA-Phos-GO/MnFeO nanohybrids very promising adsorbents for efficacious removal of heavy metals from aqueous solutions in environmental pollution cleanup.