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

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.