Simultaneous preparation of Ag/Fe₃O₄ core-shell nanocomposites with enhanced magnetic moment and strong antibacterial and catalytic properties

In this study, core-shell Ag/Fe₃O₄ nanocomposites have been successfully prepared by modified co-precipitation route followed by facile hydrothermal treatment in one-pot synthesis under various (Ag(NH3)2+) ion concentrations without adding any reducing agents. A single crystal Ag core and polycrystallized Fe₃O₄ shell nanostructures could be obtained when high amount of AgNO₃ precursor are used in the presence of Fe²⁺ ions source, i.e., ferrous salt alone. A mechanism leading to the formation of such morphologies was proposed and samples were characterized with several analytical techniques including field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FT-IR) spectroscopy. Significant increase of saturation magnetic moment was observed for the Ag/Fe₃O₄ nanocomposite. The results showed enhanced magnetic moment and strong catalytic and antibacterial activities of the present Ag/Fe₃O₄ nanocomposite, demonstrating its importance for potential application in water treatment and biomedical application, with the ability of subsequent removal by means of an external magnetic field.