Preparation and electrochemical performance of porous hematite (α-Fe2O3) nanostructures as supercapacitor electrode material

Porous α-Fe2O3 nanostructures have been synthesized by sol–gel route. The effect of preparation temperature on the morphology, structure, and electrochemical stability upon cycling has been studied for supercapacitor application. The discharge capacitance of α-Fe2O3 prepared at 300 °C is 193 F g−1, when the electrodes are cycled in 0.5 M Na2SO3 at a specific current of 1 A g−1. The capacitance retention after 1,000 cycles is about 92 % of the initial capacitance at a current density of 2 A g−1. The high discharge capacitance as well as stability of α-Fe2O3 electrodes is attributed to large surface area and porosity of the material. There is a decrease in specific capacitance (SC) on increasing the preparation temperature. As iron oxides are inexpensive, the synthetic route adopted for α-Fe2O3 in the present study is convenient and the SC is high with good cycling stability, the porous α-Fe2O3 is a potential material for supercapacitors.