Spray-printed ZnO thin film for high-sensitivity NO2 gas sensing

Abstract The controlling and precise detection of nitrogen dioxide (NO 2 ) gas is important in many industrial processes such as medical, petrochemical, and agriculture. Therefore, this study investigates the gas sensing performance of zinc oxide (ZnO) nanosheets prepared using a hydrothermal approach. The morphology and structure of the as-prepared material were analyzed using analysis techniques, including transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The ZnO ink was spray printed in a square design onto an oxidized silicon wafer substrate, which includes a lithographically designed interdigitated pattern. ZnO nanosheets exhibited superior gas sensing performance, which is 5298% for sensor response and 96 and 600 s for response and recovery times, respectively, at 150 °C and 100 ppm of NO 2 gas. The previous results emphasize applying the proposed spray printing technique in different applications because of straightforward, versatile for different substrates, and cost-effective. Graphical Abstract