Author(s)

Ling Wang, Renzhi Jiang^*

Analytical Testing Center, Huazhong University of Science and Technology, Wuhan, China.

Ammonia is toxic, colorless, and harmful to human health. It is important to detect ammonia effectively by gas sensors. In this paper, the mechanism of ammonia sensing on polypyrroles (PPy) films at room temperature has been investigated using a real-time, in-situ Fourier-transform infrared (FT-IR) spectroscopy. The introduction of ammonia results in a structural transformation of PPy films, which is confirmed by FT-IR spectrums. The structure and morphology of the products after the reaction between ammonia and PPy were investigated in detail by FT-IR spectrum and scanning electron microscope (SEM). It was found that the morphology of PPy films was changed to some degree after the reaction. Our results demonstrate that FT-IR spectroscopy is an extremely suitable technique for the characterization of the specific reaction between PPy and ammonia, since it allows monitoring the reaction at room temperature in real time. After the reaction between PPy and ammonia, the concentration of the carrier increases, and the resistance of PPy films decreases, indicating the sensitivity of detection of ammonia.

Polypyrroles, Ammonia, In-Situ FT-IR, Electrochemistry

Wang, L. and Jiang, R. (2019) Investigation on the Ammonia Sensitivity Mechanism of Conducting Polymer Polypyrroles Using In-Situ FT-IR. Materials Sciences and Applications, 10, 497-508. doi: 10.4236/msa.2019.107036.