Sub-ppm acetic acid gas sensor based on In2O3 nanofibers

Metal oxide semiconductor sensors based on nanocrystalline In 2 O 3 and its composites are found to be very sensitive in detecting low-concentration (~ 5 ppm) gases such as ozone, nitrogen dioxide, formaldehyde and butane. Here, we successfully obtained fiber-shaped In 2 O 3 crystalline nanofibers via electrospun and calcination routes. The gas sensing properties of the In 2 O 3 nanofibers were studied by exposing them to the acetic acid vapor with different concentrations from 500 ppb to 2000 ppm at the optimum operating temperature (250 °C). The device possesses ultra-high response of 66.7 toward 2000 ppm acetic acid vapor, low response and recovery times of 25 s and 37 s (100 ppm), respectively, and significant selectivity to acetic acid at 100 ppm. In particular, the sensor based on In 2 O 3 nanofibers has very low detection limit and can reach 500 ppb. Therefore, the presented In 2 O 3 nanofiber sensor can be used in practice in acetic acid detection area in the future.