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

Well-ordered titanium dioxide nanowire arrays were synthesized on the curved surface of titanium wire via hydrothermal method. The specimens were characterized respectively through scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD). It was found that the growing orientations of TiO2 nanowire were all perpendicular to the wire surface within the range of 360°. The TiO2 nanowire array were anatase after heat treatment at 450 °C for 1 h. Moreover, the optical properties of the samples were investigated by UV–vis light absorption spectrum. The growth orientation of the TiO2 nanowire was mainly affected by hydrothermal condition and the morphology of the Ti substrate. Direct electrical pathway for electron transferring and the increased light-harvesting abilities were responsible for the superior photoelectrochemical activity of the synthesized TiO2 nanowire array on curved surface of Ti wire. Furthermore, it can enlarge the practical applications range of TiO2 due to its ringed shaper and flexibility.