Ultra-high performance humidity sensor enabled by a self-assembled CuO/Ti₃C₂T MXene

An ultra-high performance humidity sensor based on a CuO/Ti₃C₂T MXene has been investigated in this work. The moisture-sensitive material was fabricated by a self-assembly method. The morphology and nanostructure of the fabricated CuO/Ti₃C₂T composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectra. The humidity sensing abilities of the CuO/Ti₃C₂T sensor in the relative humidity (RH) range from 0% to 97% were studied. The results showed that the humidity sensor had a high sensitivity of 451 kΩ/% RH, short response time (0.5 s) and recovery time (1 s), a low hysteresis value, and good repeatability. The CuO/Ti₃C₂T sensor exhibited remarkable properties in human respiration rate monitoring, finger non-contact sensing, and environmental detection. The moisture-sensitive mechanism of CuO/Ti₃C₂T was discussed. The fabricated CuO/Ti₃C₂T showed great potential in the application of moisture-sensitive materials for ultra-high-performance humidity sensors.