Enhancement of ethanol gas sensing response based on ordered V2O5 nanowire microyarns

In this paper, a prototype V2O5 nanowire microyarns-based gas sensor with high response and selectivity for ethanol was developed. The V2O5 nanowire yarns were directly spun from ultralong V2O5 nanowires viscous solution. This process is very similar to drawing a thread from a silk cocoon. The microyarns wound around alumina tubes like a spiral were tested for gas sensing toward ethanol, methanol, ammonia and toluene gases. It was found that the microyarns exhibit good response and selectivity to ethanol. The response of the yarns reaches the maximum value of 9.09 to 1000 ppm ethanol at 330 °C, which is around 3.5 times higher than that of the randomly ultralong nanowires. In contrast, only very little response was observed for methanol, ammonia and toluene, which indicated that V2O5 nanowire microyarns would be a potential candidate for practical gas detector.