Double-shell ZnO hollow microspheres prepared by template-free method for ethanol detection

Oxide semiconductors with multi-shell hollow architecture are considered favorable candidates as sensing materials for applications in high-performance gas sensors. Herein, the solid, core-shell, and double-shell zinc oxide (ZnO) microspheres were successfully prepared via a facile template-free method. Compared with solid and coreshell spheres, the gas sensor based on double-shell sphere exhibited the highest response to 100 ppm ethanol at 275 degrees C (- 47.4), which was about 4.8-fold higher than that of the solid sphere (- 9.8) under the same conditions. Furthermore, the detection limit of the double-shell ZnO microsphere could reach 1 ppm. The enhancement mechanism of the ethanol gas-sensing performance was systematically discussed.

Automated summary

Oxide semiconductors with multi-shell hollow architecture have great potential as sensing materials in high-performance gas sensors. In this study, solid, core-shell, and double-shell zinc oxide (ZnO) microspheres were successfully synthesized using a template-free method. Compared to the other two structures, the gas sensor based on the double-shell structure exhibited the highest response to 100 ppm ethanol at 275 degrees C (-47.4), which was 4.8 times higher than that of the solid structure (-9.8) under the same conditions. Furthermore, the detection limit of the double-shell ZnO microsphere was as low as 1 ppm. The enhancement mechanism of the ethanol gas-sensing performance was systematically discussed.