Highly sensitive ammonia resistive sensor based on electrospun V2O5 fibers

A simple sol–gel based electrospinning method has been applied for the synthesis of vanadium oxide/polyvinyl acetate (V2O5/PVAC) fibers for gas sensing applications. The pure phase V2O5 has been subsequently obtained by removing the polymer phase via annealing of the composite fibers in air. The as-spun V2O5/PVAC composite fibers and related products of annealing have been widely studied to characterize their morphological and microstructural properties by TG-DSC, XRD, DRIFT and SEM investigations. The application of the produced V2O5 fibers as high performance ammonia resistive sensors has been demonstrated. Reversible electrical changes have been observed by exposing V2O5 fibers deposited on interdigited electrodes to sub-ppm concentrations of ammonia gas. The fabricated V2O5 sensor has shown the highest response to ammonia gas at 200–250 ◦C, with a response and recovery time of about 50 and 350 s, respectively. A linear dependence of the response value on the ammonia concentration has been observed in the range of 0.85–8.5 ppm, with an estimated lower detection limit of about 100 ppb.