Diamine decorated graphene oxide film on quartz crystal microbalance for humidity-sensing analysis

摘要

Graphene oxide (GO) materials using various synthetic processes and amination were deposited on quartz crystal microbalance (QCM) device for humidity sensor application. Characteristics of various GO materials including surface morphology and functional groups were investigated by SEM images equipped with EDX, Fourier transform infrared spectra (FTIR) and Raman spectra. Hydrophilic property was identified by contact angle measurement. Mechanism of humidity-sensing performance are were adopted to analyze the moisture sensitivity of GO loaded QCM sensors ranging from 23% to 92% relative humidity. In this study, GO produced by strong reductant (NaNO3) and temperature control combined with amination process could generate much intercalate functional groups and high hydrophilic property. High adsorption of water molecules in graphene oxide produce large interlayer expansion of GO layers, resulting in crystal motional resistance increase, energy loss and broaden peak pattern. In humidity-sensing property, amine GO exhibits quick humidity response/recovery (10 s/11 s) sensitivity and high Q-factor, thus amination of GO film can be a candidate for future humidity sensor material.