Synthesis of hollow NiO nanostructures and their application for supercapacitor electrode

Hollow NiO nanostructures were fabricated by calcining Ni(OH)(2) precursors built on the basis of Cu2O templates. The structures and morphology of the products were characterized using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. As the temperature rose from 250 to 550 degrees C, the products showed stable cubic structures with the lengths about 600nm of a side at first, then some products deformed into cylinders and debris is generated, and the NiO nanostructures collapsed at 550 degrees C. Electrochemical test results from cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charging-discharging demonstrated that the sample synthesized at 450 degrees C showed better electrochemical properties. The hollow NiO nanostructures obtained at 450 degrees C delivered a capacitance of 1200Fg(-1) at 1Ag(-1) and displayed good rate capability with a large capacitance of 1010Fg(-1) at 5Ag(-1). After improving the cycle stability, it will exhibit a more admirable prospect of application.