Chemiresistive gas sensors based on vanadium pentoxide reinforced polyvinyl alcohol/polypyrrole blend nanocomposites for room temperature LPG sensing

In the present study, polyvinyl alcohol (PVA)/polypyrrole (WPPy)/vanadium pentoxide (V2O5) nanocomposite films were successfully synthesized by the solution casting method. The structural, optical, thermal and morphological properties of flexible PVA/WPPy/V2O5 nanocomposite films were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV-vis spectroscopy (UV), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The mechanical property investigations of PVA/WPPy/V2O5 nanocomposite films revealed excellent flexibility and enhanced ultimate tensile strength. Furthermore, the sensing properties were evaluated to ascertain the effects of V2O5 on the sensitivity, selectivity, and response/recovery time of PVA/WPPy/V2O5 nanocomposite films. The maximum sensitivity (S) of 1.16% towards liquid petroleum gas (LPG) detection at a 600 ppm concentration at mom temperature (RT) with response/recovery times of similar to 10/8 s was observed for nanocomposites with 15 wt% V2O5 loading in a PVA/WPPy blend matrix. The same composition of the nanocomposite film exhibit excellent selectivity for LPG over other tested volatile organic compounds (VOCs) such as acetone, benzene, xylene, and toluene. These results demonstrate that PVA/WPPy/V2O5 nanocomposite film with 15 wt% V2O5 loading is an ideal material as a chemiresistive sensor for the qualitative detection of LPG.