Chemical activation and magnetization of carbonaceous materials fabricated from waste plastics and their evaluation for methylene blue adsorption

Abstract

In this study, novel adsorbents were synthesized via the activation and magnetization of carbon spheres, graphene, and carbon nanotubes fabricated from plastics to improve their surface area and porosity and facilitate their separation from aqueous solutions. Fourier transform infrared spectroscopy "FTIR", X-ray diffraction "XRD", energy-dispersive X-ray spectroscopy "EDX", transmission electron microscope "TEM", and X-ray photoelectron spectroscopy "XPS" affirmed the successful activation and magnetization of the fabricated materials. Further, surface area analysis showed that the activation and magnetization enhanced the surface area. The weight loss ratio decreased from nearly 60% in the case of activated graphene to around 25% after magnetization, and the same trend was observed in the other materials confirming that magnetization improved the thermal stability of the fabricated materials. The prepared carbonaceous materials showed superparamagnetic properties according to the magnetic saturation values obtained from vibrating sample magnetometry analysis, where the magnetic saturation values were 33.77, 38.75, and 27.18 emu/g in the presence of magnetic activated carbon spheres, graphene, and carbon nanotubes, respectively. The adsorption efficiencies of methylene blue (MB) were 76.9%, 96.3%, and 74.8% in the presence of magnetic activated carbon spheres, graphene, and carbon nanotubes, respectively. This study proposes efficient adsorbents with low cost and high adsorption efficiency that can be applied on an industrial scale to remove emerging pollutants.