Novel Fe2O3/functionalized Chitosan/PVP Nanocomposites as Highly Efficient Adsorbents for the Removal of Eosin Yellow from Aqueous Solution

Three novel modified Fe₂O₃/functionalized chitosan/PVP nanocomposites, identified as KR-1, KR-2, and KR-3, were effectively synthesized using a straightforward approach. Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy - Energy Dispersive Spectroscopy (SEM-EDS), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Vibrating-Sample Magnetometer (VSM), and Brunauer-Emmett-Teller analysis (BET) characterized their physicochemical properties. The synthesized composites were utilized in batch experiments to assess their efficacy in removing eosin yellow (EY) dye from aqueous solutions. The influence of critical parameters such as initial solution pH, adsorbent dosage, and contact time on the adsorption capacity was rigorously examined. The adsorption results demonstrated that the newly developed composites are highly effective adsorbents for EY dye. The adsorption process was accurately modeled using the pseudo-second-order (PSO) kinetic and Langmuir isotherm models. Experimental data revealed that the maximum adsorption capacity of KR-3 for EY, measured at pH 4.0 and a temperature of 325 K, reached 151.5 mg g^− 1. The maximum adsorption capacity was also 136.99 mg g^− 1 for KR-1 and 130.07 mg g^− 1 for KR-2. Thermodynamic analyses determined that the adsorption mechanism is predominantly physisorption, characterized by a spontaneous and endothermic nature. Additionally, regeneration studies underscored the favorable recyclability of the adsorbent materials.