Highly sensitive ammonia resistive sensor based on electrospun V_2O_5 fibers

摘要

A simple sol-gel based electrospinning method has been applied for the synthesis of vanadium oxide/polyvinyl acetate (V_2O_5/PVAC) fibers for gas sensing applications. The pure phase V_2O_5 has been subsequently obtained by removing the polymer phase via annealing of the composite fibers in air. The as-spun V_2O_5/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 V_2O_5 fibers as high performance ammonia resistive sensors has been demonstrated. Reversible electrical changes have been observed by exposing V_2O_5 fibers deposited on interdigited electrodes to sub-ppm concentrations of ammonia gas. The fabricated V_2O_5 sensor has shown the highest response to ammonia gas at 200-250 ℃, 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.