Excellent performance of gas sensor based on In2O3–Fe2O3 nanotubes*

In2O3–Fe2O3 nanotubes are synthesized by an electrospinning method. The as-synthesized materials are characterized by scanning electron microscope and X-ray powder diffraction. The gas sensing results show that In2O3–Fe2O3 nanotubes exhibit excellent sensing properties to acetone and formaldehyde at different operating temperatures. The responses of gas sensors based on In2O3–Fe2O3 nanotubes to 100 ppm acetone and 100 ppm formaldehyde are 25 (240 °C) and 15 (260 °C), and the response/recovery times are 3/7 s and 4/7 s, respectively. The responses of In2O3–Fe2O3 nanotubes to 1 ppm acetone (240 °C) and formaldehyde (260 °C) are 3.5 and 1.8, respectively. Moreover, the gas sensor based on In2O3–Fe2O3 nanotubes also possesses an excellent selectivity to acetone and formaldehyde.