Synthesis and characterization of ring-like α-Fe₂O₃

A novel ring-like α-Fe2O3 with a cave at the centre was first synthesized via the redox reaction of Fe2+ with S2O82− in solution. The samples were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD) and vibrating sample magnetometry (VSM). The possible mechanisms of shape evolution for the formation of ring-like α-Fe2O3 were discussed. Magnetic hysteresis measurements revealed that the ring-like α-Fe2O3 display a magnetic behaviour with a coercivity of 1690 Oe at room temperature. The photocatalytic degradation of salicylic acid revealed that ring-like α-Fe2O3 exhibits a photocatalytic property.