Enhanced Removal of Cd(II) Ions from Aqueous Media via Adsorption on Facilely Synthesized Copper Ferrite Nanoparticles

In this study, magnetic copper ferrite (CuFe₂O₄) nanoparticles were synthesized via the Pechini sol-gel method and evaluated for the removal of Cd(II) ions from aqueous solutions. PF600 and PF800 refer to the samples that were synthesized at 600 °C and 800 °C, respectively. Comprehensive characterization using FTIR, XRD, FE-SEM, HR-TEM, and EDX confirmed the successful formation of CuFe₂O₄ spinel structures, with crystallite sizes of 22.64 nm (PF600) and 30.13 nm (PF800). FE-SEM analysis revealed particle diameters of 154.98 nm (PF600) and 230.05 nm (PF800), exhibiting spherical and irregular shapes. HR-TEM analysis further confirmed the presence of aggregated nanoparticles with average diameters of 52.26 nm (PF600) and 98.32 nm (PF800). The PF600 and PF800 nanoparticles exhibited exceptional adsorption capacities of 377.36 mg/g and 322.58 mg/g, respectively, significantly outperforming many materials reported in the literature. Adsorption followed the Langmuir isotherm model and pseudo-second-order kinetics, indicating monolayer adsorption and strong physisorption. The process was spontaneous, exothermic, and predominantly physical. Reusability tests demonstrated high adsorption efficiency across multiple cycles when desorbed with a 0.5 M ethylenediaminetetraacetic acid (EDTA) solution, emphasizing the practical applicability of these nanoparticles. The inherent magnetic properties of CuFe₂O₄ facilitated easy separation from the aqueous medium using a magnet, enabling efficient and cost-effective recovery of the adsorbent. These findings highlight the potential of CuFe₂O₄ nanoparticles, particularly PF600, for the effective and sustainable removal of Cd(II) ions from water.