Preparation and capacitance behavior of nickel oxide-titania nanocomposite

Titania nanotube array with an average tube diameter of 110 nm and length of 700 nm was fabricated by a potentiostatic anodization on titanium metal sheet. Nickel oxide was then loaded into titania nanotubes by electrodepositon-electrooxidation and heating treatment processes. The morphology and microstructure of the nanocomposite were investigated by field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and energy dispersive x-ray (EDX) analysis. Nickel oxide could well coat on titania nanotubes from inner wall to pore mouth with a high loading amount up to 36.4% of nickel-to-titanium atom ratio. Such a well-defined nickel oxide-titania/titanium nanotubular composite was designed as a functional electrode for an electrochemical capacitance application. The result of electrochemical characterization exhibits a highly reversible redox peaks by cyclic voltammetry in sodium hydroxide aqueous solution. High specific supercapacitance was accordingly achieved up to 7.8 mF cm-2due to the intensive loading of nickel oxide.