Abstract
•Sprayed bismuth ferrite and tungsten-doped bismuth ferrite nanostructured films are prepared by air annealing at 500 ℃ for 4 h.•The influence of tungsten-doping on the structure, morphology, surface area, and the sensor properties of bismuth ferrite are determined.•Nitrogen dioxide (NO2) and hydrogen (H2) gas sensors are improved using W-doped bismuth ferrites.•A model explaining the relative improvement in gas sensing performance is presented.
This work reports the chemical spray synthesis of bismuth ferrite (BiFeO3, abbreviated as BFO) and tungsten-doped bismuth ferrite (W-BiFeO3, abbreviated as BWFO) nanostructured films and their nitrogen dioxide (NO2) and hydrogen (H2) gas sensor applications. The influence of tungsten-doping on the structure, morphology, surface area, and the characteristics towards NO2 and H2 gas sensing of BFO has been studied and explored and also compared with pristine BFO. The W-doping in BFO, confirmed by X-ray diffraction, energy dispersive X-ray and Fourier-transform infrared spectroscopy measurements, is proposed to explain the relative improvement in gas sensing performance between BFO and BWFO nanostructured films. At dilute concentration (100 ppm) of NO2 and H2, BWFO displays an enhanced sensitivity over BFO, which is attributed to specific changes in the morphology, structure and surface area.