Biomolecule-Assisted Synthesis of In(OH)₃ Hollow Spherical Nanostructures Constructed with Well-Aligned Nanocubes and Their Conversion into C−In₂O₃

In this work, we demonstrate that indium hydroxide (In(OH) 3 ) nanospheres with hollow interior, whose shells are constructed of oriented-attachment nanocubes, have been fabricated via a dl -asparagine-assisted synthesis route without any template. NH 3 and dl -aspartic acid from the hydrolysis of dl -asparagine act as the OH − provider and the capping molecule, respectively. A detailed mechanism, involving dissolution−recrystallization and oriented aggregation processes, has been investigated on the basis of time-dependent experimental results. By annealing In(OH) 3 precursors at 400 °C in air, cubic-phase indium sesquioxide (C−In 2 O 3 ) nanocrystals, which inherit the morphology of their precursors, are also prepared.