Template-free synthesis and characterization of novel 3D urchin-like α-Fe2O3 superstructures

Abstract

Novel three-dimensional (3D) urchin-like α-Fe₂O₃ superstructures were successfully prepared by a template-free hydrothermal synthetic route using FeSO₄·7H₂O and NaClO₃ as reagents. The as-obtained products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller analysis and vibrating sample magnetometry. It is shown that the superstructures consisted of well-aligned α-Fe₂O₃ nanorods growing radially from the cores of the superstructures. The α-Fe₂O₃ nanorods have an average length of about 800 nm and a mean diameter of about 80 nm. Magnetic hysteresis measurement reveal that the urchin-like α-Fe₂O₃ superstructures display weak ferromagnetic behavior with a remanence of 4.6783 × 10⁻³ emu g⁻¹ and a coercivity of 92.235 Oe at room temperature. The formation mechanism of the 3D urchin-like α-Fe₂O₃ superstructures was also discussed.