Room temperature detection of ultrafast acetone based on photovoltaic BiFeO3 functional ZnFe2O4 hollow nanospheres

It is still a huge challenge for a chemical sensor to realize low concentration acetone detection at room temperature (RT). In this work, we present an ultrafast RT acetone sensor based on the BiFeO₃/ZnFe₂O₄ hollow core-shell nanospheres for the first time. The BiFeO₃/ZnFe₂O₄ sensor exhibited the excellent response of 41.42 towards 100 ppm acetone at RT, while ZnFe₂O₄ has almost no response in the same conditions. Further, the detection limit of BiFeO₃/ZnFe₂O₄ is low to 272 ppb at RT, which is below the range of applications for noninvasive diagnosis of diabetes. It worth noting that it showed ultrafast response/recovery ability (7/5 s) and good acetone selectivity at RT. Additionally, the performance of BiFeO₃/ZnFe₂O₄ increased by 179% under 405 nm UV irradiation compared to that without UV light. The synergistic effects of hollow spherical structures, p-n heterojunctions and excellent photovoltaic characteristics of BiFeO₃ lead to the improved performance of BiFeO₃/ZnFe₂O₄ sensor. This work holds great potential for the development of RT acetone sensors in low concentrations detection.