Regulation of O-vacancy and heterojunction structure in MOF-derived Fe2O3-Co3O4 enhancing acetone sensing performance

Abstract

In this study, a hierarchical Fe2O3-Co3O4 heterojunction with abundant oxygen vacancies was fabricated by a MOF-assisted strategy combing with a thermal treatment process. The morphology, nanostructure and other properties of the synthesized samples were comprehensively investigated by related characterizations. The results display that the Co3O4 modified with Fe2O3 nanorod exhibits an admirable mesoporous structure and abundant oxygen vacancies. In addition, the gas sensing devices were constructed by as-prepared samples and demonstrated that the gas sensor based on Fe2O3-Co3O4 composites shows excellent gas sensitivity of 91.5 towards 100 ppm acetone at a working temperature of 200 °C, with a short response-recovery time of 20/21 s. Meanwhile, the sensor possesses good reproducibility and long-term stability (over 30 days), and outstanding selectivity towards acetone gas. Exploration into a convincing gas sensing mechanism confirms that fabricating of p-n heterojunction architecture, regulating of oxygen vacancies and designing of mesoporous structure synergistically induced the excellent gas sensing performance. Therefore, this work can offer a promising strategy to enhance acetone sensing response of Fe2O3-Co3O4 in practical applications.