Coaxial electrospun of ZnO-SnO2 core-shell solid nanofibers for ethanol vapor sensing

In this work, ZnO@SnO 2 core-shell nanofibers were synthesized through a facile coaxial electrospinning method and used to detect ethanol vapor. The core-shell nanofibers were characterized using various techniques, such as XRD, SEM, TEM, and XPS. The characterization results show that the core-shell nanofibers are solid and have a higher concentration of chemisorbed oxygen species on their surface compared to both pure ZnO and SnO 2 nanofibers. The gas-sensing experiment results demonstrate that the core-shell nanofibers exhibit higher sensitivity than both pure nanofibers. Specifically, upon exposure to 100 ppm ethanol vapor at 320 °C, the response of the core-shell nanofibers is 53.2, with minimal cross-sensitivity to other interfering vapors. Additionally, the core-shell nanofibers show good repeatability and long-term stability. The superior sensing performance is attributed to the heterojunction formed between ZnO and SnO 2 , which enhances the surface chemisorption of oxygen species and facilitates efficient charge transfer.