Al2O3-doped for enhancing ethanol sensing properties of α-Fe2O3 nanotubes

In this work, pure and Al2O3-doped α-Fe2O3 nanotubes were synthesized by a simple single-capillary electrospinning technology and followed calcination treatment. The morphologies and crystal structures of the as-prepared samples were characterized by scanning electron microscopy and X-ray diffraction, respectively. The research of the samples gas sensing properties demonstrates that the ethanol sensing properties of α-Fe2O3 nanotubes are enhanced by doping Al2O3, remarkably. The response value of Al2O3-doped α-Fe2O3 nanotubes to 50 ppm ethanol is 41.8 at the operating temperature 240 °C, which is much higher than that of pure α-Fe2O3 nanotubes (response value is 4). And the lowest detection limit is 300 ppb, to which the response value is about 2. The response and recovery times are about 20 and 60 s-50 ppm ethanol, respectively. In addition, the Al2O3-doped α-Fe2O3 nanotubes possess good selectivity and long-term stability.