Controlled Sn-Doped MoO3 Nanobelts for Dual Mode Sensing of Ethanol and Temperature

Multifunctional flexible electronic sensors are highly demanded since single-function variants fail to satisfy portable/wearable electronics’ complex and growing requirements. Currently fabricated via multistep integration of single-function sensors, developing a single multifunctional sensing material remains challenging. In this study, Sn-doped MoO3 (SnxMo1–xO3) nanobelts were fabricated into a dual-mode sensor for ethanol gas and temperature detection. The Sn0.05Mo0.95O3 sensor detected ethanol at an ultralow concentration of 0.1 ppm at room temperature. Its response to 10 ppm of ethanol was 2.1 times higher than that of pure MoO3 sensor. In addition, the Sn0.05Mo0.95O3 temperature sensor demonstrated a negative temperature coefficient of resistance (TRC) of −0.0183 °C–1, an 8-fold improvement over pure MoO3. The enhanced sensing performance of Sn doping can be ascribed to four key factors: a narrowed band gap, reduced adsorption energy, increased charge transfer, and an accelerated electron transfer rate. This research provides a highly efficient sensing material with promising practical applications for dual-mode ethanol and temperature detection.