A durable gas sensor based on AgVO3/TiO2 nanoheterostructures to ethanol gas

Abstract

Semiconductor metal oxides (MOS) have been hot research topics in the field of gas sensors. However, the applicability of MOS-based gas sensors is severely constrained by the low sensitivity, poor selectivity, and high working temperature. One-dimensional AgVO3/TiO2 nanoheterostructures (NHSs) were fabricated using a hydrothermal technique to address above issues. The resulting AgVO3/TiO2 NHSs-based chemo resistive gas sensor shows good selectivity to ethanol (EtOH) gas. Moreover, the AgVO3/TiO2 with a molar ratio of 1:1 (AT) shows the highest sensing performance. The sensitivity of AT to 100 ppm EtOH at 200 ℃ is evaluated as 46.3, which is 22.0 and 1.8 times greater than that of TiO2 and AgVO3, respectively. Especially, AT possesses good sensing performance at room temperature, and its sensitivity to 100 ppm EtOH is 1.2. Simultaneously, it exhibits fast response/recovery times (17/32 s) in EtOH gas detection and excellent stability after 50 continuous cycle tests and 50 days of cycle life testing. The gas sensing mechanism is systematically analyzed from the carrier transfer ability, the synergy of AgVO3 and TiO2, the heterojunction effect, and the morphology promotion. This work reports an excellent EtOH gas sensor based on the constructed AgVO3/TiO2 NHSs, providing an insight into the fabrication of MOS-based nanocomposites for effective EtOH detection.