Controlled synthesis of α-Fe2O3 hollows from β-FeOOH rods

The β-FeOOH nanorods and α-Fe2O3 hollows are successfully fabricated via hydrothermal method. The TEM and XRD analysis indicated that the morphology and size of β-FeOOH nanorods or α-Fe2O3 hollow structure are tuned by multifactorial parameters in preparation process. The water bath temperature, urea concentrations and hydrothermal temperature promotes the diversity on the size of β-FeOOH nanorods, while hydrothermal times beneficial to the different morphologies of β-FeOOH. The calcination treatment helps the phase transformation to α-Fe2O3 and the construction of α-Fe2O3 hollow structure. However, a mature and regular α-Fe2O3 nanohollow must couple the individual roles of above reaction parameters.