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 (SnS ₂ ) nanocomposite have been fabricated. The morphology and composition of the PPy/SnS ₂ nanocomposite film were examined by means of SEM and TEM. The hydrophilicity of the PPy/SnS ₂ nanocomposite film sensor was verified by the contact angle experiment. The humidity sensing characteristics of the PPy/SnS ₂ nanocomposite sensor was studied at room temperature. The experimental results illustrated that the PPy/SnS ₂ nanocomposite 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 SnS ₂ . The Langmuir adsorption model is used to explain the humidity sensing mechanism of PPy/SnS ₂ based QCM sensor. The enhanced humidity sensing properties are attributed to the nanostructure and hydrophilicity of the PPy/SnS ₂ nanocomposite.