Sub-ppm acetone gas sensing properties of free-standing ZnO nanorods

In this paper, ZnO nanorods were synthesized by low cost and simple wet chemical method and used as a highly sensitive acetone gas sensor with detection limit as low as 25 ppb which makes the sensor a promising choice for various applications. The fabricated sensor showed a response value of 1.75 towards 25 ppb acetone at optimum working temperature of 320 °C with a response time of 30s. However, the sensor showed response value of 60 towards 50 ppm acetone with a response time of 15 s. The grown ZnO nanorods were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD) for morphology and crystallinity characterization. According to the SEM images, freestanding nanorods with mean diameter of 80 nm and mean length greater than 1.5um were obtained with highly preferential c-axis orientation.