Hydrothermal synthesis of In2O3 nanocubes and their gas sensor properties

Single crystal In(OH)
3
nanorods and nanocubes were hydrothermally synthesized from aqueous InCl
3
solution. Indium hydroxide, In(OH)
3
, was precipitated at 90°C for 12 h and was changed into a transient In
2
O
3
phase upon calcination at 400°C for 1h in air. The increase of the concentrations of indium chloride tetrahydrate would promote the formation of cube-like nanostructures. In order to understand the growth mechanism of the nanocubes, by different growth time, we can find nanocubes are primarily guided by oriented attachment. At the operating temperature of 300°C, the sensitivity is up to 2.25 and 3.25 as the sensor is exposed to 10 and 200 ppm carbon monoxide gas, respectively.