GREEN SYNTHESIS OF IRON NANOPARTICLES: STRUCTURAL CHARACTERISATION AND ADVANCED ENVIRONMENTAL APPLICATIONS

Abstract

Green synthesis offers a feasible route for preparing reactive nanomaterials without employing hazardous reductants or high-energy processing. The magnetic recoverability, coupled with their redox activity and adsorption properties, makes iron nanoparticles useful in water treatment. Yet, too many plant-mediated studies leave much to be desired in terms of stability information and test only one class of pollutants. In the present experimental study, iron nanoparticles were synthesised using Moringa oleifera leaf extract, and their structural characteristics and environmental performance were studied. Ferric chloride was reduced under alkaline aqueous conditions, then centrifuged, washed, dried, and stored under nitrogen. UV–visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, dynamic light scattering and zeta potential analysis were used to characterise the nanoparticles. The batch remediation of Cr(VI), Pb(II), Cd(II), and As(V), as well as the catalytic degradation of methylene blue and Congo red in a Fenton-like system, were evaluated. The optimised particles exhibited a UV–visible maximum at 286 nm, an Fe–O band at 584 cm−1, magnetite/maghemite reflections, a TEM diameter of 24.8 ± 6.4 nm, a hydrodynamic diameter of 61.4 ± 4.9 nm, and a zeta potential of -31.8 ± 1.2 mV. Removal efficiencies reached 92.7% for Cr(VI), 96.1% for Pb(II), 84.3% for Cd(II), and 78.4% for As(V). The efficiencies of methylene blue and Congo red degradation were 94.8% and 89.6%, respectively. This resulted in plant-capped iron nanoparticles, serving as robust, recyclable, and eco-friendly materials for the development of advanced water-purifying systems.