One step hydrothermal synthesis of Fe₂O₃/KIT-6 nanocomposite as highly responsive humidity sensor

This study presents a novel approach for the one-step hydrothermal synthesis of Fe₂O₃/KIT-6 (Korea Advanced Institute of Science and Technology) nanocomposite, demonstrating its remarkable potential as a humidity sensor at room temperature. The nanocomposite, comprised of hydrothermally derived hematite-doped hybrid moieties within a mesostructured siliceous matrix, exhibits outstanding sensitivity to moisture. Through a comprehensive characterization utilizing various techniques including X-ray diffraction, high-resolution transmission electron microscopy, field emission scanning electron microscopy, and energy dispersive X-ray analysis, the ordered mesoporous structure and purity of the synthesized nanocomposite are confirmed. Notably, the incorporation of 5 wt% Fe₂O₃ into the KIT-6 framework via hydrothermal synthesis yields superior sensing properties, characterized by minimal hysteresis, rapid response and recovery times (14s/15s), and exceptional stability within a wide relative humidity (RH) range of 11-98%. These findings pave the way for the development of practical moisture detection devices employing the silica-hematite hybrid nanocomposite as a sensing material in resistive-type sensor configurations.