Shelf Life Study of NiO Nanowire Sensors for NO2 Detection

Abstract: In this letter, conductometric sensing devices based on VLS grown NiO nanowires were presented for the detection of low concentrations of NO2. Moreover, the shelf life of sensing devices stored in ambient environmental conditions was tested over a period of 6 months. The VLS grown NiO nanowires were uniform in nature, covering completely the substrate surface area, with diameters ranging from 10 to 50 nm. The sensing devices show excellent performances, such as good stability, high response, outstanding selectivity toward NO2 and low detection limit. The devices were tested toward different analytes such as H2, acetone, NO2, etc. Indeed, at optimal working temperature, they show highly selective behavior towards NO2. Finally, the shelf life study reports that, due the exposure to the atmosphere, NiO nanowires exhibit a decrease in their conductivity, which enhances the response of the sensor. Graphic Abstract: [Figure not available: see fulltext.]