Synthesis of porous Fe3O4 hollow microspheres/graphene oxide composite for Cr(vi) removal

Abstract

A composite of porous Fe3O4 hollow microspheres/graphene oxide (Fe3O4/GO) has been fabricated through a facile self-assembly approach. Driven by the mutual electrostatic interactions, the amine-functionalized Fe3O4 microspheres prepared by a hydrothermal method and then modified by 3-aminopropyltrimethoxysilane were decorated with negatively-charged GO sheets. The Fe3O4 microspheres were hollow with porous surfaces and the surfaces were successfully modified with the amine, which was confirmed by Fourier transform infrared spectroscopy. The specific saturation magnetization of Fe3O4/GO was 37.8 emu g(-1). The sorption performance of Fe3O4/GO for Cr(vi) was evaluated. The maximum sorption capacity for Cr(vi) on Fe3O4/GO was 32.33 mg g(-1), which was much higher than that of Fe3O4 microspheres. The GO sheets could not only prevent agglomeration of the Fe3O4 microspheres and enable a good dispersion of these oxide microspheres, but also substantially enhance the specific surface area of the composite. The Fe3O4/GO composite may be a promising sorption material for the separation and preconcentration of heavy metal ions from aqueous solutions in environmental pollution cleanup.

Adsorption mechanism of magnetically separable Fe 3 O 4 /graphene oxide hybrids

“…A c c e p t e d M a n u s c r i p t adsorption capacities for the removal of cobalt (II) [16], arsenic [17], Cr(VI) [18], dye [19], Cu(II) and fulvic acid [20], and antibiotics [21] from aqueous solutions. Fe 3 O 4 @graphene oxide particles have also been used for protein adsorption [22].…”

EDTA functionalized magnetic graphene oxide for removal of Pb(II), Hg(II) and Cu(II) in water treatment: Adsorption mechanism and separation property

“…Furthermore, the large specific surface area of GO could provide abundant active attachment sites for the functionalization of EDTA. One disadvantage of nanomaterials is that it is difficult to separate them from the environmental media once they were escaped into the environment, and the small particles sizes of nanomaterials would aggravate this problem [23]. Fe 3 O 4 nanoparticles are popular magnetic materials in technological applications [24,25].…”

Modification of mesoporous silica magnetite nanoparticles by 3-aminopropyltriethoxysilane for the removal of Cr(VI) from aqueous solution

“…These methods have major drawbacks including incomplete metal removal, high reagents or energy requirements and generation of toxic sludge or secondary waste [6,7]. Therefore, the adsorption process as a high efficiency and low cost method can be used for the treatment of wastewater containing heavy metals [8,9].…”