CO Gas Sensing Behavior of Free-standing ZnO Nanowires

In this work, a conductometric gas sensor based on free-standing Zinc oxide (ZnO) nanowires with on-top gold (Au) interdigitated electrodes was fabricated. ZnO nanowires were grown through hydrothermal approach. The fabricated sensor was tested for carbon monoxide (CO) gas sensing, which the results showed response value of 3.2 towards 100 ppm CO with reasonable recovery times at working temperature of 400 °C. Morphology and crystallography of the nanowires were investigated by scanning electron microscopy (SEM) and X-Ray Diffraction (XRD) measurements. According to the XRD and SEM results, ZnO nanowires were C-axis preferential with mean diameter of 100 nm and mean length of 1300 nm.