Polypyrrole-Modified Tin Disulfide Nanoflower-Based Quartz Crystal Microbalance Sensor for Humidity Sensing

In this paper, quartz crystal microbalance (QCM) humidity sensors based on polypyrrole (PPy) modified tin disulfide (SnS2) nanocomposite have been fabricated. The morphology and composition of the PPy/SnS2nanocomposite film were examined by means of SEM and TEM. The hydrophilicity of the PPy/SnS2nanocomposite film sensor was verified by the contact angle experiment. The humidity sensing characteristics of the PPy/SnS2nanocomposite sensor was studied at room temperature. The experimental results illustrated that the PPy/SnS2nanocomposite coated QCM sensor was very sensitive to humidity and demonstrated high sensitivity, short response time, and excellent repeatability, which was surpassed the pure PPy and pure SnS2. The Langmuir adsorption model is used to explain the humidity sensing mechanism of PPy/SnS2based QCM sensor. The enhanced humidity sensing properties are attributed to the nanostructure and hydrophilicity of the PPy/SnS2nanocomposite.