Acetone gas sensing behavior of polypyrrole/ZnO nanocomposites synthesized via chemical oxidation method

This study reports the Acetone gas sensing behavior of Polypyrrole (Ppy) and Polypyrrole/Zinc Oxide (Ppy/ZnO) nanocomposites synthesized by a simple, inexpensive, and eco-friendly chemical oxidation polymerization method using methyl orange as a surfactant. The Ppy/ZnO nanocomposites were synthesized by adding Zinc Oxide with different weight percentages of 10, 15, and 20 wt% during the synthesis of Polypyrrole to enhance the electrical and chemical properties of pure Polypyrrole. The structural properties of the synthesized nanocomposites were investigated by X-ray diffraction which revealed the amorphous nature of the samples. Field Emission Scanning Electron Microscopy (FESEM) confirmed the cylindrical-shaped morphology of the prepared nanocomposites. The elemental analysis was performed using Energy-Dispersive X-ray spectroscopy. It was observed that Raman intensity was rising dramatically with an increase in ZnO concentration. Using UV/VIS spectroscopy, the materials’ light absorption was determined. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of C–H, C–C, and Zn–O chemical bonds in the nanocomposites. The highest percentage response of 41.3% was observed for Ppy/ZnO (20 wt%) at 200 ppm of Acetone. The shortest response time of the 70s was attained by the Ppy/ZnO (20 wt%) nanocomposite at 200 ppm. The Selectivity, Reproducibility, and effect of humidity were also investigated on the synthesized nanocomposites. The Selectivity was observed to be highest for Acetone as compared to that of CO₂, Hexane, and Chloroform. The percentage response was found to be increasing with the increase in humidity level. The sensing response was decreased after 180 days. These results show that Ppy/ZnO nanocomposites are a promising material for Acetone gas sensing. Ppy–ZnO hybrid materials were discovered to have two key advantages over pure Ppy and ZnO: hybrid materials had superior selectivity and sensing response than pure Ppy, and the hybrid materials’ operating temperature was significantly lower.