Oxygen defect engineering optimization for improving the performance of a fusiform hematite (α-Fe2O3) ethanol sensor

Metal-organic frameworks (MOF), as a new type of crystalline material with advantages such as high specific surface area, controllable pore size and pore structure, show great potential for application in the field of sensors. In this study, a Fe-centered Materials of institute Lavoisier frameworks (MIL) was synthesized by a simple hydrothermal method using fumaric acid, which was modified to Fe 2 O 3 by a simple heat treatment, and the sensor sensitivity was enhanced by adding oxygen vacancy defects. The composition and characterization of the materials were investigated by XRD, SEM/EDS and XPS, and the performance and stability of the gas sensors were studied using gas sensitivity tests. It is comprehensively found that oxygen vacancies (O V ) have been successfully introduced through defect engineering, and the performance of the sensor is greatly enhanced by the introduction of Ov. The Fe 2 O 3 sintered at 500 °C performs an average increase in response of about 2.45 times compared to the sample without oxygen vacancies, an ultra-low detection limit (27.74 ppt), an extremely high response (20 ppm response value of 349.39), and an excellent selectivity. The outstanding performance is due to the nature of the Fe 2 O 3 -MOF material and the introduction of oxygen vacancy defects. Therefore, oxygen defect engineering of metal-organic framework materials has the potential to be an important candidate for high-performance ethanol sensors, which provides new ideas and avenues for the development of new intelligent and high-efficiency gas sensors.