The nanostructured rutile TiO2 that have large specific surface area was formed on Ti powder through thermal oxidation. Thermal oxidation of Ti powder by using an external oxygen source was shown to be a simple and facile method to synthesize nanostructured rutile TiO2. Raw Ti powder was etched by using 30% HCl solution to control the surface morphology of Ti and to increase the surface area for effective diffusion of oxygen source. Then, etched powders were thermally oxidized at 750 and 850 degrees C with ethanol as the oxygen source. Coral-like nanostructured rutile TiO2 of size 500 nm was formed at 850 degrees C from Ti powder etched for more than 20 min. The specific surface area of the resulting powder, which consisted of intermediate oxide (Ti2O) cores covered with nanostructured rutile TiO2, was 48 times that of the raw Ti powder. (C) 2016 Elsevier B.V. All rights reserved.