Low temperature and fast response TEA sensors based on n–n WO3/In2O3 heterojunctions

Abstract

Due to the unique properties of heterojunction interfaces, heterojunction materials have broad application prospects in gas sensors. In this study, we synthesized In₂O₃ microrods through direct calcination of MIL-68(In) under ambient conditions. Subsequently, WO₃/In₂O₃ n–n heterojunction composites were built via a solvothermal method. The sensors fabricated with this heterojunction demonstrated exceptional TEA sensing capabilities, such as excellent selectivity and stability, a high response value of 678.43 to 20 ppm TEA, a fast response time (11 s) and a low operating temperature of 160 °C. The increased sensing performance is attributed to the improved specific surface area, distinct barrier-controlled electron transport present in n–n type heterojunctions, and the unique selectivity of WO₃ to TEA. This work not only offers a strategy for creating heterojunction-rich sensing materials, but also an efficient way for TEA detection.