An innovative Ag/Cu-doped polypyrrole hybrid nanocomposite gas sensor for superior ammonia detection at room temperature

Abstract

Hybrid nanocomposites combining organic and inorganic materials offer enhanced responses to reducing and oxidizing gases. This study presents a novel polypyrrole (PPy)-based hybrid nanocomposite synthesized with varying concentrations of silver (Ag) and copper (Cu) nanoparticles for efficient ammonia sensing at room temperature. The uniform dispersion of Ag/Cu nanoparticles within the PPy matrix enables a dense, smooth surface that enhances electron transport and boosts conductivity, compatibility, and catalytic activity. Structural and surface analyses using XRD, FESEM, UV-vis, EDS, TGA, and FTIR revealed that the PPy@Ag/Cu hybrid nanocomposite sensor achieved an 86% response to 300 ppm ammonia. Selectivity was confirmed against gases like carbon dioxide, carbon monoxide, ethanol, and hydrogen sulphide. The protonation and deprotonation in the PPy@Ag/Cu heterojunction contribute to the ammonia sensing mechanism, making this nanocomposite a promising material for environmental monitoring applications.