Boosting CO sensing performance based on MOFs-derived Pt decorated CeO2 nanorods with abundant oxygen vacancies

Abstract

The development of feasible and facile method to construct oxygen vacancies on metal oxides is crucial for improving their gas sensing properties. In this work, we developed a highly sensitive and stable CO gas sensor based on metal-organic frameworks (MOFs) template-derived Pt nanoparticles (NPs)-functionalized CeO2 nanorods (Pt-CeO2) with abundant oxygen vacancies through facile solvothermal method. The obtained Pt-CeO2-based sensors exhibit good thermal stability and superior CO sensing performance with high response value of 47.7% towards 500 ppm CO at 300 °C, which is higher than that of the pristine CeO2 sensor (17.8%). Moreover, Pt-CeO2-based sensor exhibits excellent selectivity, rapid response/recovery speed (9/11 s) and remarkable long-term stability toward CO. Finally, the enhanced CO sensing mechanism is proposed through a combination of experiments and characterizations, which is attributed to porous structure, abundant oxygen vacancies and electron sensitization effect of Pt NPs. This work not only provides unique insights into the facile design of metal oxide-based nanomaterials with abundant oxygen vacancies, but also has great application potential in building sensing systems for fast CO detection.