Thin film polypyrrole/SWCNTs nanocomposites-based NH3 sensor operated at room temperature

A PPY/SWCNTs nanocomposite-based sensor with relatively high sensitivity and fast response–recovery was developed for detection of NH3 gas at room temperature. The gas-sensitive composite thin film was prepared using chemical polymerization and spin-coating techniques, and characterized by Fourier transformed infrared spectra and field-emission scanning electron microscopy. The results reveal that the conjugated structure of the PPY layer was formed and the functionalized SWCNTs were well-embedded. The effects of film thickness, annealing temperature, and SWCNTs content on gas-sensing properties of the composite thin film were investigated to optimize the gas-sensing performance. The as-prepared thin film PPY/SWCNTs composite sensor with optimized process parameters had a response of 26–276% upon exposure to NH3 gas concentration from 10 to 800 ppm, and their response and recovery times were around 22 and 38 s, respectively.