Tunable synthesis of indium oxide octahedra, nanowires and tubular nanoarrow structures under oxidizing and reducing ambients.

We report the effect of oxidizing and reducing ambients on the growth of indium oxide (IO) nanostructures in the vapor phase evaporation method. Our results show that the oxidizing reagent, water, results in the growth of IO nanowires and preserves the In/O stoichiometry throughout the length of the nanowires. The reducing reagent, ethanol, makes the growth environment indium rich, resulting in the growth of indium-filled IO tubular nanoarrow structures. The growth of solid IO nanowires is attributed to a vapor-liquid-solid mechanism, whereas for indium-filled tubular nanoarrow structures a modified bottom-vapor-solid growth mechanism is proposed. The tunable synthesis of IO nanostructures in different morphologies with correction of their stoichiometry may have potential applications in future nanodevices.