Enhanced sensing of ethanol gas using fiber optics sensor by hydrothermally synthesized GO-WO<inf>3</inf> nanocomposites

We report the enhanced ethanol gas sensing nature of GO-WO3 nanocomposites using optical fiber sensors at room temperature. The monoclinic-WO3 nanoplates were synthesized by hydrothermal method and the nanocomposites with GO prepared by dispersion assisted sonication method. For the nanocomposites, the crystalline monoclinic WO3 structure was verified along with characteristic peak (0 0 1) of GO using XRD analysis. The Raman spectra show the shift in the D and G peaks for the nanocomposites along with the presence of vibrational modes of m-WO3. The ID/IG ratio for GO-WO3 nanocomposite was found to increase to 1.56. The adornment of WO3 nano plates over the 2-D GO sheets were confirmed by SEM, TEM and AFM studies. The gas sensing nature of the samples was analyzed by a clad modified optical fiber sensor. The gas sensing natures of the samples were highly improved due to the synergic effect of these nanocomposites. The GO-WO3 nanocomposite (10 wt%) had shown an enhanced gas sensitivity of 5 Counts/100 ppm towards ethanol gas over the range of 0–1000 ppm, whereas all other samples demonstrate a decrease in sensitivity.