Phyto-assisted synthesis of magnetic NiFe₂O₄ nanocomposite using the Pulicaria gnaphalodes methanolic extract for the efficient removal of an antibiotic from the aqueous solution: a study of equilibrium, kinetics, isotherms, and thermodynamics

In this research, the magnetic NiFe₂O₄ nanocomposite was synthesized using Pulicaria gnaphalodes methanolic extract and applied to remove penicillin G from aqueous solutions. The results of field emission scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared, Vibrating-Sample Magnetometer (VSM), and energy-dispersive spectroscopy-mapping analyses showed that this nanocomposite was well synthesized with a size of approximately 50–70 nm. The maximum adsorption capacity of the magnetic NiFe₂O₄ nanocomposite was 22.95 mg/g under optimal conditions. In addition, the experimental data of penicillin G adsorption by the magnetic NiFe₂O₄ nanocomposite showed that ΔH and ΔS values were positive and ΔG was negative and were following the Temkin isotherm model with R² ¼ 0.99 and follows the pseudo-second-order kinetic model.