Polypyrrole Thin Film: Room Temperature Ammonia Gas Sensor

Abstract

Polypyrrole thin films were synthesized in situ by chemical polymerization. The morphological studies by Scanning Electron Microscopy showed formation of uniform granular structure with average grain size of 0.6 μm. Fourier transform infrared spectroscopy revealed formation of polypyrrole. The film composition was also characterized by UV-Vis Spectroscopy. These films were investigated for their sensing behavior towards NH ₃ , C ₂ H ₅ OH and CH ₃ OH gases at room temperature. It has been observed that these films are selective for ammonia gas, and the sensitivity exhibited a linear response in range of 5-100 ppm. These studies show that polypyrrole films can be used as room temperature ammonia sensors.