Self-templated fabrication of shuttle-like WO3 functionalized with Co3O4 nanobox for efficient detection of acetone

Abstract

In this work, a self-template in situ etching strategy was applied to fabricate a hollow shuttle-like WO₃-Co₃O₄ heterojunction. The morphology and nanostructure were investigated comprehensively by a series of techniques. Notably, the hollow shuttle-like WO₃-Co₃O₄ shows a large specific area and promising architecture, which can efficiently promote the gas adsorption-desorption process and provide more active sites in whole composites. Compared to other sensing devices, the WO₃-Co₃O₄ sample with hollow shuttle-like architecture shows the best gas sensing characterizations, and the response to 100 ppm acetone is as high as 52 under optimum working temperature. Moreover, it also presents good repeatability, high against moisture, fast response-recovery speed and long-term stability. The enhanced gas sensing characterizations can be ascribed to the synergistic effect of a unique hollow shuttle-like structure and the p-n heterojunction at the interface of WO₃ and Co₃O₄. These admirable properties make it an excellent candidate for constructing high-performance acetone sensors. In addition, the relative sensing mechanism of shuttle-like WO₃-Co₃O₄ composites-based sensors will be discussed in detail.