Excellent acetone sensing properties of Sm-doped α-Fe2O3

Pure and 3   wt% Sm-doped α-Fe 2 O 3 nanotubes are prepared via a typical electrospinning technology and calcination procedure. The characteristic and morphology of the synthesized nanotubes are investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). Compared with pure α-Fe 2 O 3 nanotubes, 3   wt% Sm-doped α-Fe 2 O 3 nanotubes display enhanced gas-sensing properties. The response of 3   wt% Sm-doped α-Fe 2 O 3 nanotubes is 33–50   ppm acetone, which is 13 times larger than that of pure α-Fe 2 O 3 nanotubes. The lowest detection limit of acetone is 500   ppb to which the response is 2.3 at the optimum operating temperature of 240   °C. The response and recovery times are about 6 and 11   s to 50   ppm acetone, respectively. In addition, 3   wt% Sm-doped α-Fe 2 O 3 nanotubes exhibit good selectivity and long term stability.