Tailoring the surface morphology of TiO2 nanotube arrays connected with nanowires by anodization

Abstract Different surface morphologies of TiO 2 nanotube arrays were formed by anodization of Ti foils in various water-containing electrolytes at various voltages. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were used to investigate the morphology of TiO 2 nanowires. The results show that the morphology of TiO 2 nanowires is apparently influenced by viscosity of electrolytes and voltage. In this case, we introduce a detailed formation mechanism of nanowires that shows a strong relationship between the formation of TiO 2 nanowires and TiF 6 2− concentration. It was also found that TiO 2 nanowires are polycrystalline with anatase phase after annealing at 450 °C for 3 h.