High-sensitive ethanol gas sensor using Ag modified ZnO nanosheets

In this study, an ethanol gas sensor was developed using ZnO nanosheets synthesized through an aqueous solution method, with Ag nanoparticles modified on the surface via chemical reduction to enhance ethanol gas sensing capabilities. We discuss the optimal sensitivity, selectivity, stability and optimal operating temperature conditions of Ag/ZnO samples. The selectivity measurement included methanol, ethanol, isopropanol and propanol, and the results showed that Ag/ZnO sample has the best selectivity for ethanol gas and the best sensitivity to ethanol gas (100 ppm, 28.78) when the device operates at 270 °C compared to ZnO sample (100 ppm, 2.27). The flaky structure of the ZnO nanosheets provides a high surface-to-volume ratio, which is beneficial for gas sensing. The addition of Ag nanoparticles further improves the gas sensor performance due to the Ag nanoparticles can more readily capture electrons. The results indicate that the Ag-modified ZnO nanosheet gas sensor exhibits the highest selectivity, excellent stability, and high responsiveness to ethanol gas compared to the ZnO sensor.