Highly sensitive acetone sensors based on La-doped α-Fe2O3 nanotubes

Pure and La-doped (5 wt%, 7 wt% and 10 wt%) α-Fe2O3 nanotubes are synthesized by an electrospinning method and followed by calcination. The as-synthesized nanotubes are characterized by scanning electron microscope (SEM) and X-ray powder diffraction (XRD). Compared with pure α-Fe2O3 nanotubes, La-doped α-Fe2O3 nanotubes exhibit improved acetone sensing properties at 240 °C. The response of 7 wt% La-doped α-Fe2O3 nanotubes to 50 ppm acetone is about 26, which is 10 times larger than that of pure α-Fe2O3 nanotubes. The response and recovery times of 7 wt% La-doped α-Fe2O3 nanotubes to 50 ppm acetone are about 3 and 10 s, respectively. Moreover, 7 wt% La-doped α-Fe2O3 nanotubes show a good selectivity to acetone.