MoS₂/Graphene Oxide/C₆₀-OH Nanostructures Deposited on a Quartz Crystal Microbalance Transducer for Humidity Sensing

In this work, MoS2/graphene oxide (GO)/C60-OH nanocomposites are synthesized by a hydrothermal method and deposited on a quartz crystal microbalance (QCM) transducer for humidity detection. Microscopic characterization shows that the nanocomposites are composed of GO/C60-OH composite encapsulated MoS2 nanoflowers. The QCM humidity sensor with MoS2/GO/C60-OH nanocomposites as the sensing film demonstrates an excellent response and recovery times (1.3/1.2 s), which are shorter than most QCM humidity sensors proposed at present. Meanwhile, the QCM humidity sensor has a high sensitivity (31.8 Hz/% RH), which is approximately 3 times that of the QCM humidity sensor based on pure GO. It is possible that the support of MoS2 nanoflowers significantly weakens the stacking effect of GO films and accelerates the diffusion rate of water molecules in the composites. Besides this, the addition of C60-OHs can also greatly increase water absorption sites in the composites, thus improving the sensor’s humidity-sensitive response. Owing to its fast response/recovery rate, the proposed MoS2/GO/C60-OH-based QCM humidity sensor can be used for human respiratory status detection with digital frequency output signals.