Monodispersed In2O3 mesoporous nanospheres: One-step facile synthesis and the improved gas-sensing performance

Abstract

Mesoporous In2O3 nanospheres were successfully synthesized by a simple solvothermal route, which was performed without the assistance of any additives or templates. The obtained mesoporous In2O3 nanospheres show high monodispersity with average size about 90nm and pore size about 2–4nm. The optical absorption property of the In2O3 mesoporous spheres was investigated by UV–vis spectroscopy, which indicates that the In2O3 mesoporous spheres are semiconducting with a direct band gap of 3.1eV. The gas sensing performance of the as-prepared In2O3 mesoporous nanospheres was investigated towards a series of typical organic solvents and fuels. For 100ppm of butanol and ethanol, the mesoporous In2O3 demonstrates sensing responses of 59.6 and 29.6, respectively. These values are much higher than those of the reported In2O3-based gas sensors and the In2O3 powder sample with similar size, indicating the highly enhanced gas sensing performance of In2O3 mesoporous nanospheres. The obtained In2O3 mesoporous nanospheres appear to be a promising sensing material for environmental detection application and would also find applications in catalyst, electrode, or related fields.