▎ 摘　　要

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 degrees 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. (C) 2021 The Authors. Publishing services by Elsevier B.V. on behalf of Vietnam National University, Hanoi.