One-step green synthesis of bimetallic Fe/Ni nanoparticles by eucalyptus leaf extract: Biomolecules identification, characterization and catalytic activity

Both Fe nanoparticles (Fe NPs) and bimetallic Fe/Ni nanoparticles (Fe/Ni NPs) were synthesized using eucalyptus leaf extracts. More than eight major compounds in eucalyptus leaf extracts, which may serve as reducing and capping agents, were identified using Gas Chromatography-Mass Spectrometer (GC-MS). The obtained Fe NPs and Fe/Ni NPs were characterized using Fourier Translation Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TG), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray Diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS). The results demonstrated that: (1) the presence of Fe in Fe NPs, and Fe and Ni in Fe/Ni NPs; (2) the coating organic compounds may be responsible for the capping and efficient stabilization of Fe and Fe/Ni NPs. Fe NPs and Fe/Ni NPs were then used to degrade methyl orange (MO) in aqueous solution. Only 29.2% of MO was removed from aqueous solution using Fe NPs, while 99.6% of MO was removed using Fe/Ni NPs. Furthermore the removal of MO using Fe NPs and Fe/Ni NPs followed pseudo-first-order kinetics.