Ce-Doped BiFeO3 with Enhanced Polarization and Phase Boundary Engineering for Ultrasensitive Acetone Detection and Real-time Leakage Warning.

Real-time and highly selective monitoring of acetone (C3H6O) is crucial for industrial safety and occupational health. Herein, we report a Ce-doped BiFeO3 (BFO) sensing material synthesized via a sol-gel method, which enables simultaneous regulation of grain size, polarization strength, crystal phase composition, band structure, and defect. The optimized sensor (denoted as BC2FO, 2 mol% Ce-doped) exhibits excellent C3H6O sensing performance over a concentration range of 0.2-10 ppm at 220 °C, and its response value to 2 ppm C3H6O is twice that of the pure BFO sensor. Ex situ XPS and in situ Raman further revealed the sensitive reaction mechanism between C3H6O gas molecules and the BC2FO composite material. Furthermore, the machine learning classification algorithm was introduced for highly accurate identification of C3H6O against isopropanol (C3H8O). An intelligent warning system based on BC2FO micro-electro-mechanical system (MEMS) sensors has been developed, which successfully achieved continuous monitoring and automatic on-site alarm in simulated industrial leakage scenarios. This study presents a comprehensive and robust paradigm combining material engineering, machine learning-assisted recognition, and hardware integration for the detection of C3H6O.