Facile preparation of rutile TiO2 nanorod arrays in a low HCL concentration vapor environment by AVO process and characterizations

In this study, oriented rutile TiO2 nanorod arrays (NRAs) were directly grown on the titanium (Ti) thin films deposited on the Si substrate in a low concentration of hydrochloric acid aqueous solution vapor environment called acid vapor oxidation (AVO) process which is a facile and environmentally friendly hydrothermal route without using any catalysts, seeds or templates. The growth of the TiO2 NRAs can be controlled by adjusting the key experimental parameters, such as growth time and low HCL concentration and so on. The effects of the key experimental parameters on their morphologies and crystal structures were explored in detail by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and selected area electron diffraction. The results indicate that the growth time and the low HCL concentration have influence on tailoring the crystal structures, like density, diameter and crystallinity of the TiO2 NRAs. The rutile TiO2 NRAs were single crystalline and grown along the [1 0 1] direction. The rutile TiO2 NRAs prepared in a low HCL concentration vapor environment by AVO process could be widely used in kinds of applications, especially gas sensors which will be explored further in the follow work.