Methyl Orange Adsorption onto Magnetic Fe₃O₄/Carbon (AC, GO, PGO) Nanocomposites

Abstract

In this study, carbonaceous nanomaterials (Activated Carbon (AC), Graphene Oxide (GO) and Porous Graphene Oxide (PGO)) were synthesized and attached to Fe3O4 magnetic powder for the effective removal of synthetic Methyl Orange (MO). AC and GO were successfully conjugated with Fe3O4 whilst PGO was not due to its surface functional groups. The morphology and chemical structure of the Fe3O4/Carbon nanocomposites were characterized by the N2 adsorption, Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscope (TEM) and Vibrating sample magnetometer (VSM). Batch adsorption experiments were performed and showed significant removal efficiency of 90% at the first ten minutes for Fe3O4/AC nanocomposite. Analysis of adsorption equilibrium revealed that AC/Fe3O4 is well fitted with Langmuir model, a homogeneous adsorption having an adsorption capacity of 270 mg/g. The GO/Fe3O4 can fit with both Langmuir and Freundlich models indicating multilayer adsorption on the surface of the adsorbent with an adsorption capacity of 81.9 mg/g. In the case of adsorption kinetics, both adsorbents follow the pseudo second order kinetics model showing high F?2 values. Both adsorbents demonstrated advantageous superparamagnetic properties for their easy recovery from aqueous solutions and prospective applications to toxic removal in water and wastewater.