Ammonia gas-sensing behavior of uniform nanostructured PPy film prepared by simple-straightforward in situ chemical vapor oxidation

• Published in: Open Physics 2023-02, Vol.21 (1), p.1-19
• Main Authors: Van Nguyen, Khong, Trung, Bui Ha, Van Tuan, Chu, Doanh Sai, Cong, Vu, Tung Duy, Trung, Tran, Thai, Giang Hong, Giang, Ho Truong, Hien, Hoang Thi
• Format: Article
• Language: English
• Subjects: chemical vapor polymerization; conducting polymer; gas sensing; nanostructured polypyrrole; room temperature NH; room temperature nh3 gas sensing
• ISSN: 2391-5471; 2391-5471
• DOI: 10.1515/phys-2022-0232

A highly uniform nanostructured polypyrrole (PPy) film prepared by a simple, straightforward route of chemical vapor oxidation has been demonstrated as a sensitive substrate for NH gas sensing. The structure of PPy film was investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The binding characteristics of the functional groups of the PPy film were examined by Fourier transform infrared and Raman spectroscopy. NH sensing properties of the PPy film were evaluated by its resistive response to gas concentrations from 45 to 350 ppm at different temperatures ranging from 25 to 100°C. The sensing response maximum value was 142.6% when exposed to 350 ppm of NH gas at room temperature (25°C). The sensing response of PPy film shows an excellent linear relationship and high selectivity toward NH . The NH sensing mechanism is due to the physisorption and chemisorption interactions of NH molecules and the adsorptive sites of PPy (polaron and bipolaron charging carriers).