High Sensitivity Ethanol Gas Sensor Based on Hollow F-Doped SnO₂ Nanofibers

In this letter, we investigated the preparation of F-doped SnO2 nanofibers with hollow structure by combining electrostatic spinning technology with calcination process for gas sensors. The structures of F-doped SnO2 nanofibers were characterized by X-ray diffraction (XRD), energy dispersive spectrometer (EDS), scanning electron microscope (SEM), and transmission electron microscopy (TEM). In gas sensitivity tests on various gases, we found that the response of F-doped SnO2 hollow nanofibers to a concentration of 100 ppm ethanol was 104, which is 14 times higher than that of a pure SnO2 sensor (about 7) when the temperature reached the optimum temperature of 325°C. The response time and recovery time were 27 s and 10 s, respectively, and the theoretical detection limit of the sensor was as low as 2.94 ppm. The sensor also offers good selectivity, repeatability and long-term stability. This research demonstrates the potential of F-doped SnO2 nanofibers as a highly reliable, high-performance sensing layer for ethanol gas sensors.