Highly sensitive and selective ultrasonically nebulized V2O5 thin films towards ethanol and NO2 gas detection

The global demand for improved living standards coupled with the rising emission of pollutant/hazardous gases which are detrimental to human life and the environment have led to the increasing need for the development of highly efficient and low-cost gas sensors; to detect, quantify and isolate the pollutant/hazardous gaseous species from their sources or environments. Herein, we report the synthesis, characterization, and gas sensing properties of low-cost, high-quality V2O5 thin films ultrasonically nebulized on quartz substrate at three different temperatures: 350 degrees C (V2O5-Qu-350), 400 degrees C (V2O5-Qu-400) and 450 degrees C (V2O5-Qu-450). Phase formation and purity were revealed by X-ray diffraction and confirmed by Raman measurements. Morphological investigation by SEM showed the highly porous nature of the thin films. We investigated the effect of deposition temperature on the gas sensing properties of synthesized V2O5 thin films. The V2O5-Qu-350, V2O5-Qu-400 and V2O5-Qu-450 thin films were used to fabricate the gas sensing devices. Their response towards various concentrations of ethanol, NO2, CO, and other volatile organic compounds (VOCs) like acetone, n-hexane and propan-2-ol at different operating temperatures were studied using an in-house built sensing setup. The chosen analytes are common industrial solvents or hazardous pollutants. The V2O5-Qu-350 thin films showed the highest response towards ethanol (88.1) and NO2(809.4) at an optimized operating temperature of 280 degrees C. Further, the V2O5-Qu-350 thin films demonstrated high selectivity towards ethanol when subjected to CO and other VOCs like acetone, nhexane and propan-2-ol. Our samples exhibited better performance than that of the reported V2O5-based gas sensors.