Ammonia sensing properties of metal-organic frameworks-derived zinc oxide/reduced graphene oxide nanocomposite

This work reported a high-performance room temperature ammonia (NH3) gas sensor, which was prepared by metal-organic frameworks (MOFs)-derived zinc oxide (ZnO)/reduced graphene oxide (rGO) nanocomposite. The sensor was prepared by depositing MOFs-derived ZnO/rGO film on an epoxy substrate with interdigital electrodes (IDEs). The microstructure and elementary composition of ZnO/rGO nanocomposite were measured and analyzed by using XRD, SEM, XPS and TEM measurements. The sensing performance of the prepared sensor was measured over a range of 0.5-30 ppm of ammonia gas. According to test results, the MOFs-derived ZnO/rGO sensor has a better sensing performance toward ammonia gas detection than that of ZIF8-ZnO and rGO sensors. The sensor exhibits high response (6.46@30 ppm), quick response/recovery time (50 s/25 s), low detection limit (0.5 ppm), excellent stability and well selectivity when the sensor was exposed to ammonia. The response-concentration curve shows good linear relationship (Y = 0.910 + 0.186X) within a certain range (0.5-30 ppm). Finally, the excellent performance of the sensor is explained by analyzing surface structure of MOFs ZnO/rGO and ammonia gas adsorption model.