Hydrophilic TiO2 nanowires prepared on Ti5Si3 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.