Preparation and electrochemical properties of mesoporous α-Fe2O3 nanowires for supercapacitor application

Mesoporous α-Fe₂O₃ nanowires have been prepared through solid-state thermal conversion of ferrous oxalate dihydrate precursor for supercapacitor application. The possible growth mechanism of the FeC₂O₄·2H₂O nanowires was proposed based on a series of time-dependent experiments. The specific surface area and pore size distribution of the mesoporous α-Fe₂O₃ nanowires were calculated to be about 70.6 m² g⁻¹ and 2.5 nm, respectively. Furthermore, electrochemical measurements demonstrate that the as-prepared mesoporous α-Fe₂O₃ nanowire electrode delivers a high specific capacitance up to 267.5 F g⁻¹ at 2 A g⁻¹ and good cycle performance (87% capacitance retention under 2000 cycles). The excellent supercapacitor performance of the α-Fe₂O₃ nanowires can be ascribed mainly to the unique mesoporous structure with large specific surface area, which provide fast electron/ion transfer path as well as large reaction surface area.