Magnetic tubular carbon nanofibers as efficient Cu(II) ion adsorbent from wastewater

Novel magnetic tubular carbon nanofibers (MTCFs) were prepared from hypercrosslinked α, ά-dichloro-p-xylene as a green adsorbent for efficient Cu(II) ion removal from the wastewater. The new route involving the following steps, such as dual oil phase polymerization, carboxyl functionalization and loading of magnetic nanoparticles (Fe₃O₄) was developed. The surface area, saturation magnetization, inner and outer diameters of MTCFs are 280.94 m²/g, 10.65 emu/g, 25 nm and 110 nm. The adsorption properties were studied by batch methods. The highest removal efficiency for Cu(II) ion was achieved 99.9 ± 0.1% in a short contact time 10 min and a small amount of MTCFs dosage 0.5 g/L with pH = 6. From kinetic studies, the Pseudo first order kinetic model was best fitted with experimental data than the Pseudo second order. From isothermal studies, the Langmuir model was best fixed with the highest R² in contrast to the Freundlich isotherm model. The highest adsorption for Cu(II) ion 375.93 mg/g was achieved from the Langmuir isotherm. The parameters determined from thermodynamics ΔGᵒ, ΔHᵒ, ΔSᵒ confirmed Cu(II) ion adsorption was spontaneous, thermodynamically it was endothermic and random adsorption process. Regeneration and reuse of MTCFs up to six cycles with the same contact for all adsorption cycles.