Synthesis and Characterization of PPy-Fe(ClO4)2-Ag Nano-Composite and Their Study in H2S Gas Sensor at Room Temperature

Objectives: The study aimed to synthesize and characterize a polypyrrole (PPy) nanocomposite doped with iron perchlorate [Fe(ClO4)2] and silver nanoparticles (Ag-NPs) for potential application as a room-temperature gas sensor, specifically targeting hydrogen sulfide (H2S) gas detection. Methods: The PPy nanocomposite was synthesized through in situ chemical polymerization using ferric chloride (FeCl3) as the oxidant, with a monomer-to-oxidant ratio of 1:1. Silver nanoparticles were prepared using the Turkevich method and incorporated as dopants. The structural, morphological, and chemical properties of the synthesized nanocomposite were analyzed using SEM, TEM, UV-Vis, FTIR and XRD techniques. Electrical conductivity was measured using a two-probe technique, and the material's gas-sensing performance was evaluated by exposing it to H2S gas. Findings: The synthesized PPy-Fe(ClO4)2-Ag nanocomposite demonstrated excellent sensitivity to H2S gas at room temperature. A sharp increase in current was observed upon exposure to H2S gas, which quickly reverted when the gas was removed. The characterization results confirmed the successful incorporation of Ag nanoparticles and Fe(ClO4)2 into the PPy matrix, contributing to its enhanced electrical and sensing properties. Novelty: This study highlights the innovative use of a PPy-based nanocomposite doped with iron perchlorate and silver nanoparticles for highly sensitive and reversible H2S gas detection at room temperature. The combination of these dopants enhances the material's electrical conductivity and sensing capabilities, offering a promising candidate for low-cost, efficient gas sensor applications. Keywords: Polypyrrole, Silver nanoparticles, Iron per Chlorate, H2S, Gas sensor