ErFeO3/α-Fe2O3 nanocomposites derived from MIL-100(Fe) for acetone sensing

Acetone, a flammable and volatile liquid, is toxic and can affect human well-being. Additionally, its presence in exhaled air can indicate the state of human respiratory health. Therefore, the investigation of an acetone gas sensor holds significant urgency in the realm of scientific research. Metal-organic frameworks (MOFs) exhibit significant promise in the field of gas detection due to their extensive surface areas, remarkable porosity, and the inclusion of unsaturated metallic sites. The study conducted the preparation of ErFeO3/α-Fe2O3 nanocomposites through impregnation and oxidation roasting methods. EF21 (MEr(NO3)3∙6H2O:MMIL-100(Fe) = 2:1) exhibited a large surface area of 43.7 m2/g and a high abundant oxygen vacancy of 12.5 %. Gas sensing experiments revealed that the EF21-based gas sensor exhibited a strong response of 55 towards 100 ppm acetone, with a low detection limit of 2 ppm (S = 3.3). Notably, the sensor demonstrated excellent selectivity towards acetone over other volatile organic compounds (e.g., ethanol, methanol, ammonia, ether, and toluene) in gas selectivity tests. Moreover, the EF21-based gas sensor maintained its responsiveness to acetone even under high relative humidity conditions (RH:90 %, S = 27) and demonstrated stability over a 15-day long-term test. The study provided a comprehensive explanation of the gas sensing mechanism responsible for the enhanced performance observed in ErFeO3/α-Fe2O3 through detailed analyses.