Synthesis and Characterization of Fe−Fe₂O₃ Core−Shell Nanowires and Nanonecklaces

Fe−Fe 2 O 3 core−shell nanowires and nanonecklaces were obtained simply through controlling the reduction rate of Fe 3+ ions by sodium borohydride in aqueous solution at ambient atmosphere. The resulting materials were characterized by X-ray powder diffraction, scanning electron microscopy images and energy dispersive X-ray spectrum, transmission electron microscopy, elemental mapping, X-ray photoemission spectroscopy, and magnetization measurements. A possible formation mechanism was proposed on the basis of characterization results. It was interesting to find that the core−shell nanowires used in electrochemical-assisted and ultrasound-assisted Fenton-like reaction systems could much more efficiently degrade organic pollutant in aqueous solutions than traditional Fenton reagent Fe 2+ ions under neutral pH and pH 2, respectively. This study indicates that the resulting iron-containing nanostructures are promising materials in magnetic, environmental, and catalytic fields.