Titania nanotubes arrays based-gas sensor: NO2Oxidizing gas and H2-reducing gas

Abstract

Gas sensor based on titanium dioxide (TiO2) nanotube was manufactured and its sensitivity to hydrogen (H2) and to nitrogen dioxide (NO2) gasses was investigated using anodization method. The TiO2 NT structure was studied using X-ray diffraction (XRD). The surface morphology of prepared Titania was analysed using field-emission electron-scanning microscopy (FE-SEM). Starting with (XRD) study it confirms the tetragonal phase structure of the prepared Titania (anatase and rutile). In addition, the TiO2 anatase averaged crystallite size was 25.9 nm. The FE-SEM images revealed that the nanotube's average diameters are within 70 ± 2 nm. Gas response measurements at room temperature (27 °C) for hydrogen and nitrogen dioxide gases at various concentrations (100, 150, 200, 250 and 300 ppm) were investigated. Our study has shown that the higher resistance of NO2 gas was 30 Ω at 300 ppm while it was equal 18.29 Ω at 150 ppm for H2 gas at room temperature.