Detection of humidity based on quartz crystal microbalance coated with ZnO nanostructure films

The possibilities and properties of ZnO nanorod and nanowire films-coated quartz crystal microbalance (QCM) as a humidity sensor have been investigated. The morphology and crystal structures of ZnO nanorods and nanowires were characterized with X-ray diffraction (XRD) and scanning electron microscopy (SEM). It can be found that the frequency shift of the ZnO nanostructures-coated QCM linearly decreases with increasing relative humidity over the range of 5-97% RH. The experimental results demonstrated that ZnO nanostructures-coated QCM are usable as a humidity sensor and as an analytical device. It appears that the ZnO nanomaterial films can be used as efficient humidity sensors.