Construction of Co3O4/SnO2 yolk-shell nanofibers for acetone gas detection

In this work, Co3O4/SnO2 heterojunctions were proposed and fabricated by single-nozzle electrospinning. Interestingly, novel yolk-shell nanofibers could be formed in a proper doped content of Co3O4. The gas sensing properties of sensors based on Co3O4/SnO2 yolk-shell nanofibers were evaluated, and a superior response of ∼216–100 ppm acetone at 350 °C was obtained. Additionally, Our sensors have an ultrafast response time of ∼0.62 s, demonstrating remarkable selectivity for acetone and excellent stability for both humidity and long-term use. These exceptional performances are attributed to the synergistic effect of nano-heterojunctions that enhance the effective interfacial area, as well as the unique yolk-shell structure of SnO2/Co3O4, which increases gas transport channels. Our results demonstrate that constructing Co3O4/SnO2 yolk-shell nanofibers is an effective strategy for achieving high-performance acetone gas detection. •Co3O4/SnO2 yolk-shell nanofibers are synthesized by single-nozzle electrospinning.•The yolk-shell structure increases effective interfacial area of heterojunctions.•The yolk-shell structure exhibits more gas transport channels.•The formation mechanism of yolk-shell nanofibers is reasonably conjectured.•The Co3O4/SnO2 yolk-shell nanofibers show enhanced acetone sensing performance.