Improved acetone gas sensing performance based on optimization of a transition metal doped WO₃ system at room temperature

This paper proposes an effective strategy of material system optimization to improve acetone gas sensing performance based on hydrothermally processed transition metal (Fe, Co or Ni)-doped WO₃ materials. A detailed comparison of the capability of pure WO₃ and X:WO₃ (X = Fe, Co, Ni) to sense acetone gas at room temperature was performed. It was found that the sensitivity of Ni:WO₃ nanoflowers to acetone was much higher than that of pure WO₃, Fe:WO₃ and Co:WO₃ under white light irradiation. To obtain a highly sensitive acetone gas sensor, the molar doping ratio of Ni to WO₃ was further optimized. It was found that 3%Ni:WO₃ had the highest response–recovery speed and the best target gas selectivity. Acetone with a concentration as low as 2 ppm can be detected at room temperature (20 °C). The sensitivity enhancement mechanism of the Ni:WO₃ gas sensor is also discussed. It is expected that under white light irradiation the proposed Ni-doped WO₃ can be used as a highly sensitive and selective acetone gas sensor at room temperature. (paper)