Facile hydrothermal synthesis and electrochemical properties of flowerlike α-FeOOH

Flowerlike alpha-FeOOH products were successfully prepared through hydrothermal treatment of ammonium iron (II) sulphate solution without extra template or surfactant. The as-prepared products were characterised by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and Fourier transform infrared spectroscopy. It was found that the reaction temperature and time were critical for the formation of flowerlike alpha-FeOOH products. The results revealed that the flowerlike alpha-FeOOH was single-crystal structure in nature. Furthermore, the electrochemical properties of flowerlike alpha-FeOOH were investigated by cyclic voltammetry and galvanostatic charge-discharge measurements. A pair of electrochemical redox peaks presenting on each cyclic voltammogram indicated the existence of Faradic process, which was a signature of pseudocapacitance. The shape of charge-discharge curve displayed typical characteristics of Faradic deposition. Flowerlike alpha-FeOOH showed a good electrochemical performance, which may be a promising candidate as electrode material for supercapacitors.