Fe2O3 nanowires for thermoelectric nitrogen dioxide gas sensor

A thermoelectric nitrogen dioxide gas sensor developed based on Fe2O3 nanowires is capable of outputting DC voltages of tens of millivolts, which facilitates signal amplification and processing. In this paper, the Fe2O3 nanowires were synthesized in a horizontal electrical furnace under air pressure at 600°C for 8 h. SEM and XRD techniques as well as gas sensing performance of prepared sensors towards NO2 gas were studied. The gas sensing studies demonstrate that, The voltage signal, corresponding to the 10 ppm of NO2 gas was 17.9 mV, the response time and the recovery time were 23 s and 17 s, respectively, when the temperature difference was set at 120°C. Furthermore, the plausible response mechanism of the thermoelectric gas sensor based on Fe2O3 was discussed that demonstrates a feasible method for nitrogen dioxide detection.