A QCM Humidity Sensors Based on GO/Nafion Composite Films With Enhanced Sensitivity

A novel humidity sensor was made of quartz crystal microbalance and graphene oxide (GO)/Nafion nanocomposites. The humidity sensing properties of the sensor, such as sensitivity, stability, humidity hysteresis, dynamic response, and recovery, were investigated by monitoring changes in both resonant frequency and impedance spectrum. The results of the investigation showed the introduction of GO in Nafion matrix significantly enhanced sensitivity of the humidity sensors and maintained higher stability. Possible interpretation is that the introduction of GO sheets improves the hydrophilic property and mechanical property of GO/Nafion nanocomposites due to unique properties of GO. Meanwhile, the sensors based on GO/Nafion nanocomposite films exhibited a narrow humidity hysteresis.