SnO2-doped α-Fe2O3 patulous microtubes for high performance formaldehyde sensing

SnO2-doped α-FezO3 patulous microtubes （SFPNs） are synthesized by an electrospinning method. The as-synthesized materials are characterized by scanning electron microscope, X-ray powder diffraction and energy dispersive spectroscopy. The gas sensing results show SFPNs possess an excellent sensing property to formalde- hyde. The response value of SFPNs gas sensor to 50 ppm formaldehyde is 25.4 at 220℃. The lowest detecting limit of 1 ppm formaldehyde is 3.2. Response and recovery characteristic curves of SFPNs gas sensors to 1, 2, 3, 5, 5, 3, 2 and 1 ppm formaldehyde are also tested. The results show a good reversibility and repeatability of SFPNs gas sensors. The sensor exhibits a high selectivity in the presence of acetone, ethanol, toluene, ammonia, hydrogen, carbon monoxide and butane. Moreover, the sensor has a good long-time stability.