Enhanced ethanol sensing performance of Fe: TiO2 nanowires and their mechanism of sensing at room temperature

TiO2 and Fe-doped TiO2 nanowires were synthesized by spray pyrolysis technique to study their gas sensing properties towards ethanol. Charge transfer from metal dopant to TiO2, and modification of TiO2 with Fe doping was investigated for their ability to enhance gas sensing activity. The X-ray diffraction results indicate that the Fe dopant was substitutionally incorporated by replacing Ti4+ cations. Fourier transform infrared spectral analysis confirmed the presence of brookite TiO2. The UV–visible spectra showed the increase in absorption with Fe doping when compared with undoped TiO2 film, and optical band gap decreased slightly with Fe doping. SEM images revealed the presence of one dimensional structure of straight nanowires for undoped TiO2 and curved nanowires for Fe doped TiO2 films. To understand the enhancement of sensing performance of TiO2 film with Fe doping, the gas sensing mechanism of the film towards Ethanol at room temperature was studied and discussed.