Diameter-controlled growth of In2O3 nanowires on the surfaces of indium grains

In2O3 nanowires have been synthesized on a large-area surface by direct thermal oxidation of indium grains coated with an Au film at 700-850 °C under the flow of O2. The indium grains were used as both a reagent and a substrate for the growth of In2O3 nanowires. The as-synthesized In2O3 nanowires were characterized by transmission electron microscopy, scanning electron microscopy and Raman spectrum. It was found that the In2O3 nanowires were a polycrystalline with the body centered cubic structure and had a controllable diameter in the range of 60-250 nm with lengths of up to 10 μm by varying the heating temperature. A possible mechanism was also proposed to account for the growth of these In2O3 nanowires.