Synthesis and characterization of AlxCu0.7Mn0.3Fe2-xO4 ferrite and its application in adsorption of dyes

Abstract

The increasing presence of artificial dyes in industrial wastewater has necessitated the development of efficient and sustainable adsorption materials. This work explores the synthesis and characterization of Al-doped Cu-Mn (AlxCu0.7Mn0.3Fe2-xO4, where x = 0.1, 0.3, 0.5, 0.7, and 0.9) ferrite as a new adsorbent for the removal of dyes from aqueous solutions. The Al-doped Cu-Mn ferrite was prepared using the solution combustion method and meticulously characterized using various physiochemical techniques, including scanning electron microscopy (SEM) analysis, Fourier transform infrared spectroscopy (FTIR), X-ray powder diffractometer (XRD), vibrating sample magnetometer (VSM), and Brunauer-Emmer-Teller (BET). Adsorption studies tested the material's ability to remove hazardous dyes such as congo red, methyl orange, methylene blue, and crystal violet from aqueous solutions. The effects of various parameters, including temperature, contact time, and initial dye concentration, were systematically studied. To understand the mechanism of interaction between the adsorbent and the dyes, the adsorption isotherms were examined using the Langmuir, Temkin, D-R, and Freundlich models. The Freundlich isotherms provided the best fit for the experimental data. To clarify the kinetics of the adsorption process, kinetic experiments were conducted using pseudo-first and pseudo-second-order. According to the results of the kinetics analysis, pseudo-second-order kinetics fit the data better, with a higher coefficient of determination values (R2 = 0.981, 0.983, 0.984 & 0.984). Thermodynamic parameters, including enthalpy, Gibbs free energy, and entropy changes, were calculated to determine the nature of the adsorption process, and the result demonstrates that the adsorption process was endothermic and naturally spontaneous. The results indicate that Al-doped Cu-Mn ferrite exhibits high adsorption capacities and favourable thermodynamic properties, making it a promising material for the removal of dyes from industrial wastewater effluents. The study contributes to the field by providing insights into the adsorption mechanisms and potential applications of Al-doped Cu-Mn ferrite in environmental remediation.