Size- and Surface-Determined Transformations: From Ultrathin InOOH Nanowires to Uniform c-In₂O₃ Nanocubes and rh-In₂O₃ Nanowires

Ultrathin InOOH nanowires with a diameter of ∼2 nm and a length up to ∼200 nm have been synthesized by a hydrolysis reaction in a solution system. Their transformations to c-In₂O₃ nanocrystals and rh-In₂O₃ nanowires have been investigated. A dissolution−recrystallization (in solution) or size-related decomposition−recrystallization (in air) mechanism is indicated for the former transformation; the size- and surface-determined transformation is proposed for the latter. These results will help to understand and control the phase stability and transformation concerning the nanodimension and surface restrictions, especially for ultrathin nanowires.