In-MIL-68 derived In2O3/Fe2O3 shuttle-like structures with n–n heterojunctions to improve ethanol sensing performance

Abstract

Metal–organic frameworks (MOFs) have a variety of structures and unique properties that make them suitable for use in gas sensors. Herein, In₂O₃/Fe₂O₃ was successfully synthesized using simple solvothermal and impregnation methods. The response to 100 ppm of ethanol gas reached 67.5 at an optimum working temperature of 200 °C, and the response/recovery time was 9 s/236 s. The composite also exhibited excellent selectivity, repeatability, and long-term stability. SEM, TEM, XRD, and XPS were used for the characterization of materials. The excellent sensing performance of the sensors is attributed to the construction of n–n heterojunctions, an increase in oxygen vacancies, and the unique structural characteristics of MOFs. The above experimental results indicate that In-MIL-68-derived In₂O₃/Fe₂O₃ is a promising ethanol sensing material.