Synthesis of In2O3 hollow nanofibers and their application in highly sensitive detection of acetone

In this study, indium oxide (In2O3) hollow nanofibers were synthesized through a two-step process. In2O3 solid nanofibers were prepared by electrospinning, and 10% HNO3 was used to corrode these nanofibers to obtain In2O3 hollow nanofibers. Moreover, the effects of corrosion on the morphology and acetone-sensing properties of In2O3 nanofibers were investigated. In2O3 nanofibers that were corroded for 2 h displayed hollow structures and exhibited a high response (resistance ratio) of 151 to 5 ppm of acetone at 300 °C. The minimum detection limit was 20 ppb. The hollow In2O3 nanofibers also exhibited high selectivity to acetone along with negligible cross-responses to interference gases at 300 °C, These gases include NO2, H2, CO, benzene, p-xylene, and toluene. The strong response to acetone was attributed to the enhanced accessibility of gas for gas-sensing reactions due to the hollow morphology.