Synthesis and characterization of La- and Ce-codoped polycrystal ZnO prepared by hydrothermal method for 1,2-propanediol

La/Ce-codoped ZnO (La/Ce-ZnO)-based gas sensors are successfully prepared by a simple mild hydrothermal method. And the structures, morphologies and sensing properties are examined by XRD, SEM and XPS, respectively. The 1,2-propanediol gas-sensing analysis reveals that the La/Ce-ZnO-based gas sensor displays the highest response compared with La-doped ZnO and Ce-doped ZnO sensors. La/Ce-ZnO-based gas sensor exhibits an excellent response (681) and possesses good response and recovery property of 11 and 45s to 100ppm 1,2-propanediol at 240 degrees C, respectively. The mechanism of gas sensing and enhanced gas response of La/Ce-ZnO is discussed.