Boosted Antioxidant and Photocatalytic Power: Reusable PEG-Coated Iron Oxide Nanocomposites for Effective Cephalexin and BCB Dye Degradation

Abstract

In this study, α-Fe₂O₃/Fe₃O₄ nanocomposite (NC) coated with polyethylene glycol were synthesized via hydrothermal synthesis, achieving uniform particle formation and controlled crystallinity. Characterization using Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV–Vis), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDAX) confirmed the physical attributes and homogeneity of the nanocomposite. Polyethylene glycol-coated α-Fe₂O₃/Fe₃O₄ showed a reduced crystalline size of 19.13 nm compared to 22.93 nm for uncoated nanoparticles. Optical band gap measurements revealed values of 4.64 electron volts for polyethylene glycol, 1.98 electron volts for α-Fe₂O₃/Fe₃O₄ NC, and 3.18 electron volts for α-Fe₂O₃/Fe₃O₄@polyethylene glycol nanocomposites, indicating both insulating and semiconducting behaviors. The photocatalytic performance of the polyethylene glycol-coated α-Fe₂O₃/Fe₃O₄ was demonstrated by a 99.4% degradation of Brilliant Cresyl Blue (BCB) dye within 120 minutes at a concentration of 5 milligrams per milliliter, with a pseudo-first-order rate constant of 0.02047 per minute. Furthermore, the nanocomposites exhibited strong recyclability and reusability, making them viable candidates for environmental remediation. The study underscores the potential of α-Fe₂O₃/Fe₃O₄ NC in applications such as water treatment and antioxidant therapies.