Preparation of magnetic porous graphene oxide by intercalating rigid molecule and subsequent magnetization for enhancing pharmaceuticals removal from water

A novel magnetic porous graphene oxide (GO-DFe) was prepared by growing Fe3O4 via an impregnation method in the nanoscale channel of porous GO (GO-DFP), which was fabricated by chemically intercalating 4,4′-Diaminooctafluorodiphenyl (DFP) into the GO sheets. In this study, the concentrations of Fe2+/Fe3+ was optimized to obtain the GO-DFe5 adsorbent with good adsorption and separation performance. The adsorption performance of magnetic GO-DFe5 towards sulfadiazine (SD) and carbamazepine (CBZ) was evaluated, and adsorption kinetic models (the first-order, the second-order, Elovich and intra-particle models) and isotherm models (Langmuir and Freundlich models) were applied to study the adsorption rate and capacity. The effects of solution pH, ions (Cl- and NO3-) and co-existed matters in effluent of municipal wastewater on the adsorption behavior of SD and CBZ on GO-DFe5 were further clarified. Additionally, the cyclic reuse performance of GO-DFe5 for SD and CBZ were also evaluated, and the potential adsorption mechanism was proposed by theoretical calculation. The as-prepared GO-DFe5 adsorbent exhibited high adsorption capacities for SD (380.67 μmol/g) and CBZ (350.70 μmol/g). The adsorption amounts of GO-DFe5 for two pharmaceuticals about were 3.0 and 2.1 times higher than that of GO according to the second-order model. π-π interaction, hydrogen bonding and electrostatic interaction were involved in the adsorption of SD and CBZ on GO-DFe5. GO-DFe5 in water can be easily recovered by a magnet and exhibited a well reuse performance for SD and CBZ within 6 cycles.