Effect of Pr/Zn on the anti-humidity and acetone-sensing properties of Co3O4 prepared by electrospray

Abstract

Co3O4 is a P-type metal-oxide semiconductor which can realize acetone detection at a lower temperature, but the lower working temperature brings the enhanced humidity effect. In order to solve the problem of a Co3O4 gas sensor being easily affected by humidity, an acetone-sensing material of Co3O4 mixed with Pr/Zn was prepared by electrospray in this work. The optimal working temperature of Pr/Zn-Co3O4 is 160 °C, and the detection limit can reach 1 ppm. The fluctuation of the acetone response is about 7.7% in the relative humidity range of 30-90%. Compared with pure Co3O4, the anti-humidity property of this material is obviously enhanced, but the gas-sensing response deteriorates. Compared with Pr-Co3O4, the anti-humidity and acetone sensing properties of Pr/Zn-Co3O4 were both improved. The morphology, composition, crystal state and energy state of the material were analyzed by SEM, EDS, XRD and XPS. The material of Pr/Zn-Co3O4 is a multi-component mixed material composed of PrCoO3, ZnO, Pr6O11 and Co3O4. The improved anti-humidity and acetone sensing properties exhibited by this material are the result of the synergistic effect of ZnO and Pr3+