Facile synthesis of single crystalline mesoporous hematite nanorods with enhanced supercapacitive performance

α-Fe2O3 nanorods with a length of 400–700 nm and a diameter of 20–80 nm, which have single-crystalline and mesoporous structure, could be obtained from these α-FeOOH precursors after calcining at 300 °C in air. The as-prepared single-crystalline mesoporous α-Fe2O3 nanorodes exhibited a large specific surface area and porosity, effectively increasing the contact area between the electrode materials and electrolyte, minimizing both the ionic and electronic transportation in the Fe2O3 during the charge-discharge process. The porous nanostructure facilitates the faster faradic reaction toward electrolytes and delivers highest specific capacitance (534 F g−1) and an excellent long cycle life (upto 1500 cycles) in 1 M KOH electrolyte at current density of 4 A g−1, demonstrating that the porous α-Fe2O3 nanorods can serve as an excellent electrode material for supercapacitors. It is believed that the single-crystalline mesoporous α-Fe2O3 nanorods are beneficial to the charge transfer in the electrode and to the ion transport in the solution during redox reaction.