Facile synthesis of polypyrrole coated graphene Gr/Ag–Ag2O/PPy nanocomposites for a rapid and selective response towards ammonia sensing at room temperature

Abstract

This work demonstrates the fabrication of a highly selective ammonia (NH3) gas sensor based on Graphene/Silver–Silver Oxide/Polypyyrole (Gr/Ag–Ag2O/PPy) nanocomposite. To archive this objective, a cost-effective, room temperature mediated solution-based synthesis of Gr/Ag–Ag2O/PPy nanocomposite was exploited as an efficient performance NH3 gas sensor through combining the exceptional electrical characteristics of Graphene and sensing abilities of Ag–Ag2O/PPy. The as-synthesized nanomaterials were examined for relative DC conductivity with ammonia vapors' exposure at room temperature (25 °C) with the electrical signals' changes. The incorporation of Gr/Ag–Ag2O in PPy revealed about 40 times higher amplitude of conductivity change as compared to pristine PPy on exposure to the ammonia vapors. The reversibility response of Gr/Ag–Ag2O/PPy regarding the DC electrical conductivity with an effective variation range from 9.15 S/cm to 6.48 S/cm was observed in the ambient air on exposure to 1000 ppm of ammonia vapors. Gr/Ag–Ag2O/PPy was shown to offer a more excellent selectivity toward ammonia due to its basicity compared to different volatile organic compounds.

Keywords

• Graphene
• Polypyrrole
• Ag–Ag2O
• Ammonia
• Sensing