Applied novel sensing material graphene/polypyrrole for humidity sensor

A novel sensing graphene/polypyrrole (PPy) material was prepared by a chemical oxidative polymerization method with various weight percentages of graphene. The structure and morphology were characterized by XRD (X-ray diffraction), FTIR (Fourier transform infrared), TEM (transmission electron microscopy), UV–vis spectrometry and TGA (thermo-gravimetric analysis). The humidity sensing properties were measured by using an LCR (inductance, capacitance and resistance) analyzer. The results indicate that the sample with 10% graphene/PPy had better humidity sensing properties than the other samples at relative humidity (RH) in the range 12–90%. The response and recovery times were approximately 15 s and 20 s, respectively. The prepared sensor has a higher sensitivity (S = 138) than those developed elsewhere and the humidity hysteresis value was very small at all humidities (<0.16%). The results herein demonstrate the potential of graphene/PPy composite for use in fabricating high-performance humidity sensors.