Rational in situ construction of Fe-modified MXene-derived MOFs as high-performance acetone sensor

Acetone, with diverse applications in multiple areas, may pose a risk to industrial safety and human health. For the purpose of detecting the leakage and concentration of acetone, we have successfully prepared [MIL-125(Ti)/FexTiyOz]T-X (MFTT-X) gas-sensitive materials by in-situ solvothermal and calcination methods. Herein, the porous MIL-125(Ti) and FexTiyOz nanoparticles with intimate interfaces are grown on the template of exfoliated Ti3C2Tx nanosheets that simultaneously serve as the Ti source. The narrower bandgap, numerous surface defects, increased specific surface area, and mesoporous structure of MFTT-X composites are conducive to the diffusion and contact among acetone gas and active sites. The optimum MFT450-8 composite endows significantly enhanced sensitivity (R = 351.1) towards 100 ppm acetone at 222 °C, ultrafast response and recovery time (16 s / 5 s), good repeatability, and excellent selectivity. These results provide new insight into the design of high-performance sensing materials, modified with MXene derived MOFs, and analyzed the reaction mechanism of acetone that is relevant to MFT450-8 composite.