ZnO/ZnCo2O4 composite prepared by one-step hydrothermal method for high-performance ethylene glycol sensor

ZnO/ZnCo2O4 nanoparticles were successfully prepared by one-step hydrothermal method. It was characterized by XRD, SEM, TEM and XPS. The results show that the surface of ZnO/ZnCo2O4 nanoparticles is rough and the chemisorbed oxygen content (55%) is high, which may be one of the reasons for the high response to ethylene glycol gas. The gas sensitive properties of ZnO/ZnCo2O4 were tested and compared with pure ZnCo2O4 prepared by the same method. The results show that the response of ZnO/ZnCo2O4 sensor to ethylene glycol gas is 4.27 times higher (15.63) than that of ZnCo2O4 sensor (3.66). It also has excellent selectivity, good stability and repeatability. It is worth noting that the ZnO/ZnCo2O4 gas sensor has a low operating temperature (160 °C), so it has the characteristics of low consumption. In addition, the mechanism by which the p-n heterojunction can improve the gas sensitivity is discussed.