Ag–Co ferrite-based magnetic polymeric composite film: a breakthrough in cationic dye remediation for sustainable environment†

The deployment of magnetically responsive and polymeric materials to remove dyes that are hazardous in aquatic environments has profoundly revolutionized environmental sustainability. This study focuses on removing the hazardous cationic Malachite Green (MG) dye from solutions, employing a novel magnetic composite film as an adsorbent, designated as Ag_0.2Co_0.8 Fe₂O₄ (ACFCeP). The composite was synthesized via solvent casting, incorporating Ag_0.2Co_0.8 Fe₂O₄ nanoparticles and CeO₂ into a cellulose acetate/polyvinylpyrrolidone (CA/PVP) polymer matrix. The Ag_0.2Co_0.8Fe₂O₄ nanoparticles were synthesized by a co-precipitation method. Comprehensive characterization of the synthesized composite was conducted using techniques, such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), and vibrating sample magnetometer (VSM). The Ag-doped cobalt ferrite component retained a strong hysteresis loop within the final composite, even when blended with the CA/PVP polymer, preserving the robust magnetic properties that facilitate the easy removal of the composite post-treatment without secondary pollution. Additionally, the mesoporous structure of the composite effectively aids in the adsorption mechanism. The isothermal study shows that both linear Langmuir isotherm and Freundlich isotherm are well fitted with R² values of 0.99 and 0.97, respectively. The linear Langmuir maximum adsorption capacity, q_max, is 45.66 mg g⁻¹ at pH 7. The kinetic studies of the composite resemble the pseudo-second-order kinetic model, reaching adsorption equilibrium within 70 min for a 100 ppm MG dye concentration. The composite film exhibits excellent reusability, maintaining high removal efficiency over three cycles. Overall, the ACFCeP composite film showcases excellent dye removal capabilities, a fast adsorption rate, and satisfactory magnetic properties and offers a sustainable solution for environmental pollution, thus contributing to ecosystem preservation through efficient recycling and reuse in dye adsorption applications.