Morphology control of α-Fe 2 O 3 towards super electrochemistry performance.

α-Fe 2 O 3 with various morphologies including spindle, rod, tube, disk, and ring were synthesized through controlling the H 2 PO 4 - etching process. The concentrations of H 2 PO 4 - plays an important role in controlling the morphology change of the samples. Selected adsorption of H 2 PO 4 - ions resulted in anisotropic growth. In addition, the etching of H 2 PO 4 - occurred in the center of rods which resulted in tubal α-Fe 2 O 3 . Nanodiscs were created once the etching process occurred on the wall of the tube. The electrochemical test shows that disklike samples revealed excellent specific capacitance, rate capacity and cycling stability because of relative higher surface area and pore structure. For the CO catalytic oxidation properties, spindle samples exhibited super catalytic activity.