Y-branched TiO2 nanotube arrays synthesized by anodic oxidation

Abstract

We report a novel synthesis strategy for Y-branched TiO2 nanotubes on a pure titanium foil by electrochemical anodic oxidation in an NH4F organic electrolyte. Effects of temperature range, oxidation time, and morphology-dependent parameters of the Y-branched TiO2 nanotube arrays were investigated. We found that an optimized growth-temperature window between 20°C and 30°C resulted in Y-branched nanotubes with much better morphology and photoelectric performances. After annealing at 450°C for 1.5 h in air, a dominant crystal structure of these arrays was indexed to anatase.