rGO/RuO₂/PPy nanocomposite: a promising platform for repeatable, selective, long-term stable, and room-temperature TEA sensing with p-n transition.

This study reports the successful synthesis of a novel ternary nanocomposite (NC) comprising reduced graphene oxide, ruthenium dioxide, and polypyrrole (rGO/RuO2/PPy) by in-situ chemical oxidative polymerization of PPy in the presence of hydrothermally prepared binary rGO/RuO2 NC. The samples were characterized by SEM, EDX, X-map, XRD, FTIR, Raman, XPS, BET, and TGA techniques. The prepared NCs were utilized as chemo-resistive sensing layers for the detection of triethylamine (TEA). Under similar conditions, the rGO/RuO2/PPy NC exhibited improved TEA sensing capability, with enhanced sensitivity compared to rGO/RuO2 NC. The rGO/RuO2/PPy NC showed the room temperature response of 16% against low concentration of 20 ppm TEA (75% against 100 ppm) with excellent selectivity toward TEA as compared with ammonia, toluene, ethanol, methanol, acetone and methane. Moreover, the rGO/RuO2/PPy NC demonstrated ultrafast response/recovery times of 2.5/6 s against 20 ppm TEA at 150 °C. Additionally, a temperature-dependent p- to n-type behavior transition was observed upon exposure of rGO/RuO2/PPy NC to TEA at a turning temperature of 150 °C. rGO/RuO2/PPy NC displayed exceptional properties such as good selectivity, considerable stability, high response value, and fast response time, making it a promising candidate for TEA gas sensor applications.