Effect of lanthanum oxide content on the magnetic (Co/Mn)Fe2O4-graphite nano-composites for industrial wastewater treatment application

This research endeavors to elucidate the impact of varying lanthanum ion concentration on the structural, magnetic, dielectric, and adsorption isotherms of Co 0.5-x Mn 0.5 Fe 2 O 4 /Graphite Nano composites in the context of industrial wastewater remediation. Nanoparticles of La x Co 0.5-x Mn 0.5 Fe 2 O 4 /Graphite (where x = 0, 0.005, 0.010, 0.015, and 0.020 wt%) were synthesized effectively via mixing of the used chemical compounds in the powder form in agate mortar for 30 min, followed by the sol-gel auto-combustion technique. X-ray diffraction (XRD) analysis corroborated the emergence of a novel two new phase cubic spinel structure alongside a hematite phase. La 2 O 3 -modified Co-Mn ferrite/graphite nanocomposites were synthesized by the sol-gel auto-combustion method, and the results confirmed the formation of a multiphase structure composed mainly of spinel ferrite and graphite, with minor hematite and La 2 O 3 -related secondary phases. The surface microstructure of the composites was scrutinized through field emission scanning electron microscopy (FE-SEM). Energy dispersive spectroscopy (EDS) analysis affirmed the presence of the anticipated chemical constituents within the samples. Fourier-transform infrared (FT-IR) spectroscopy further substantiated the formation of both the spinel structure and the hematite phase. The magnetic characteristics, assessed utilizing a vibrating sample magnetometer (VSM), demonstrated a progressive increase in saturation magnetization from 8.4624 emu/g to 22.007 emu/g concomitant with elevated levels of lanthanum doping. The dielectric response exhibited a frequency-dependent decrease, with the dielectric constant ε ′ varying approximately from 2.32 × 10 4 to 1.03 × 10 4 , while the dielectric loss factor ε ′ ′ decreased toward nearly zero at high frequency. Furthermore, the catalytic activity of the samples for sulfamethazine antibiotic was assessed, with the sample containing La 2 O 3 = 0.02 wt% exhibiting the highest efficiency in the removal of sulfamethazine from wastewater.