Fabrication of mesoporous In2O3 nanospheres and their ultrasensitive NO2 sensing properties

Ultra-sensitive NO2 sensor based on hierarchical In2O3 nanospheres which are successfully fabricated via facile thermal processes. Such morphology evolution is investigated by the time-dependent experiment. Remarkable features of the mesoporous structure and, large specific area (82.1 m2/g) and small sized nanoparticles result in the In2O3 nanospheres a high NO2 sensing efficiency. For the In2O3 based NO2 sensor, temperature of annealing process is an important factor to influence its sensing performance; the rather high sensitivity (360.1, 100 ppb) and low detection limit (1 ppb) are realized at 120 °C for the sample that annealed at 500 °C. Based on the preferable sensing performance, the novel In2O3 sensor is believed to be promising to be applied for practised NO2 detecting.