Porous hierarchical In2O3 nanostructures: Hydrothermal preparation and gas sensing properties

In2O3 hierarchical nanostructures were successfully synthesized by a simple calcination of InOOH precursor obtained with a hydrothermal method in the presence of sucrose and urea. The as-synthesized samples were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The results clearly revealed that the hierarchical nanostructure of In2O3 was composed of aggregated nanosheets with pore size about 14 nm. Gas sensing properties of as-prepared In2O3 hierarchical nanostructures were investigated. It was found that the sensor based on such novel nanostructures exhibited high response and good repeatability to NO2 at room temperature.