Oriented TiO2 nanowire array grown on curved surface of Ti wire with superior photoelectrochemical properties

► Well aligned TiO2 nanowire arrays were prepared on the curved surface of the titanium wires via hydrothermal method. ► Hydrothermal condition and the morphology of the Ti substrate affect the growth orientation of the TiO2 nanowire. ► TiO2 nanowire arrays/Ti wire electrode shows superior photoelectrochemical properties. ► We report a facile method for preparing crystallized TiO2 nanowire arrays on Ti wire substrate.