Hydrophilic TiO 2 nanowires prepared on Ti 5 Si 3 layer by chemical vapour deposition

Abstract

Here we report a self-induced catalyst-free preparation of TiO₂ nanowires by APCVD. High-density single-crystalline hydrophilic TiO₂ nanowires have been successfully prepared on a Ti₅Si₃ layer by chemical vapour deposition at 720 °C using 10 SCCM O₂ for 120 min, using SiH₄, TiCl₄, and O₂ as precursors. The nanowires are approximately 2–5 μm long, the diameter is about 20–40 nm. The TiO₂ nanowires grow along the [001] direction of the tetragonal rutile TiO₂ crystal from the bottom, with the tip being pushed upwards. The growth process can be defined as a self-induced growth. The 432 and 463 nm band of TiO₂ nanowires assigned to self-trapped excitons and OVs, which is beneficial for the hydrophilic property of the nanowires. The contact angle of TiO₂ nanowires after ultraviolet irradiation is low (5.1°), exhibiting excellent hydrophilic property.