Facile hydrothermal synthesis and electrochemical properties of hollow urchin-like αFeOOH

Hollow urchin-like α-FeOOH was successfully prepared without template or surfactant, employing a facile route incorporating hydrothermal treatment with ammonium iron (III) sulphate solution. α-FeOOH was characterised by X-ray diffraction, thermal gravimetric analysis, scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and Fourier transform infrared spectroscopy. The Ostwald ripening process was believed to be the main driving force for the formation of hollow urchin-like architectures. Furthermore, the electrochemical properties of hollow urchin-like α-FeOOH were investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge measurements. The CV results implied that the capacitance was mainly associated with the redox mechanism. The specific capacitance value was 88.5 F/g calculated from the discharge curve at the current density of 0.5 A.g. The hollow urchin-like α-FeOOH shows a good electrochemical performance.