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⁺.