Electrical Conductivity Based Ammonia Sensing Properties of Polypyrrole/MoS₂ Nanocomposite

Polypyrrole (PPy) and Polypyrrole/MoS₂ (PPy/MoS₂) nanocomposites were successfully prepared, characterized and studied for ammonia sensing properties. The as-prepared PPy and PPy/MoS₂ nanocomposites were confirmed by FTIR (Fourier transform infrared spectroscopy), XRD (X-ray diffraction), SEM (scanning electron microscopy) and TEM (transmission electron microscopy) techniques. The ammonia sensing properties of PPy and PPy/MoS₂ nanocomposites were studied in terms of change in DC electrical conductivity on exposure to ammonia vapors followed by ambient air at room temperature. It was observed that the incorporation of MoS₂ in PPy showed high sensitivity, significant stability and excellent reversibility. The enhanced sensing properties of PPy/MoS₂ nanocomposites could be attributed to comparatively high surface area, appropriate sensing channels and efficiently available active sites. The sensing mechanism is explained on the basis of simple acid-base chemistry of polypyrrole.