Pure and 0.18-13.2 at.% Fe-doped NiO nanofibers were prepared by electrospinning and their gas sensing characteristics and microstructural evolution were investigated. The responses ((Rg - R a)/Ra, where Rg is the resistance in gas and Ra is the resistance in air) to 5 ppm C2H5OH, toluene, benzene, p-xylene, HCHO, CO, H2, and NH3 at 350-500°C were significantly enhanced by Fe doping of the NiO nanofibers, while the responses of pure NiO nanofibers to all the analyte gases were very low ((Rg - Ra)/Ra = 0.07-0.78). In particular, the response to 100 ppm C2H5OH was enhanced up to 217.86 times by doping of NiO nanofibers with 3.04 at.% Fe. The variation in the gas response was closely dependent upon changes in the base resistance of the sensors in air. The enhanced gas response of Fe-doped NiO nanofibers was explained in relation to electronic sensitization, that is, the increase in the chemoresistive variation due to the decrease in the hole concentration induced by Fe doping.
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Mechanical Engineering
- Mechanics of Materials
- Materials Science(all)