High-yield synthesis of single crystalline tin-doped indium oxide octahedrons via a low-temperature, catalyst-free process.

We report a large-scale synthesis of micron and nanosized tin-doped indium oxide (ITO) octahedrons via an ultrasonic spray assisted chemical vapour deposition, in which no catalyst is involved. The single crystalline nature of the ITO octahedrons was revealed by high-resolution transmission electron microscopy. The formation of ITO octahedrons, which are bounded by eight {111} facets, is due to the lowest surface energy of the {111} facet. The size of the octahedron was found to be strongly dependent on deposition temperature and the concentration of the precursor solution, with perfectly shaped ITO octahedrons being synthesized at a temperature between 400 and 550 degrees C. By simply changing the concentration of the precursor solution, we can produce well-dispersed ITO octahedral particles, dense ITO films with octahedral grains, or clusters of octahedral.