Impedance analysis of quartz crystal microbalance humidity sensors based on nanodiamond/graphene oxide nanocomposite film

In this work, detonation nanodiamond (DND)/graphene oxide (GO) nanocomposites with various weight ratios were prepared. By combining with quartz crystal microbalance (QCM) technique, the humidity sensing properties of these nanocomposites sensors, including response sensitivity, humidity hysteresis, dynamic response and recovery, were studied through an impedance analysis method. The test results indicated that DND/GO nanocomposites showed high humidity response sensitivity, logarithmic linear response, fast response/recovery and small humidity hysteresis. Moreover, the influence of DND content in nanocomposite on the humidity response sensitivity and quality factor of the sensors has also been discussed. The results revealed that the increase of DND content in nanocomposite could enhance the humidity response sensitivity, but reduce the quality factor of the sensor. So, it is very necessary to select a suitable DND content in nanocomposite for balancing the sensitivity and quality factor. In addition, the reasons for the enhanced humidity sensing performance have also been discussed in detail. This work demonstrated that DND/GO nanocomposite is a promise candidate material for humidity sensing detection by combing with QCM technique.