Metastable Titanium Dioxide B-Phase Nanowire Prepared by Hydrothermal Method

TiO2-Bronze phase nanowires have been synthesized by hydrothermal method. The influence of post hydrothermal annealing temperature on the formation of TiO2-B NWs has been explored. X-ray diffraction results indicate that the TiO2 NWs consist of Bronze phase (B) only. Transmission electron microscope (TEM) images further confirm the formation of TiO2-B nanowire structure oriented towards dominant <001> and <110> directions. The optical study reveals that the absorption edge red shifted towards longer wavelength with increase in annealing temperature. Band gap narrowing enhances absorption of solar spectrum and oriented growth towards dominant <001> and <110> directions. Coupling of intrinsic channels and the preferentially exposed [010] facets introduces open channels in metastable TiO2-B which may enhance photocatalytic activity due to large surface area creating adsorptive and reactive sites to accelerate the reactions.