Synergistic enhancement of CO gas sensing performance using SnO2-Integrated polypyrrole/graphene oxide nanocomposites

This work explores how integrating SnO₂ nanoparticles into polypyrrole/graphene oxide (PPy/GO) nanocomposites unlocks synergistic enhancements in carbon monoxide (CO) gas sensing capabilities. The SnO₂/PPy/GO nanocomposite was synthesized using in-situ polymerization and solution mixing techniques, and its structural, morphological, and optical properties were characterized using XRD, FTIR, Raman, UV–visible spectroscopy, and FESEM. The gas sensing performance was evaluated using a custom-designed dynamic gas-sensing system. The SnO₂/PPy/GO nanocomposite exhibited a superior CO response of 252 at 10 ppm, significantly outperforming PPy (response of 61) and PPy/GO (response of 92). Additionally, the sensor demonstrated excellent linearity (R2 = 0.99648), with response and recovery times of 85 s and 65 s, respectively. Long-term stability tests over 60 days showed minimal degradation, with a variation of less than 5 % in sensor response. Furthermore, the SnO₂/PPy/GO sensor displayed remarkable selectivity towards CO over interfering gases like NO₂, NH₃, SO₂, and H₂S. The enhanced performance is attributed to the combined benefits of SnO₂‘s catalytic properties, GO's high surface area, and PPy's adsorption capabilities. This work presents a promising material for sensitive, selective, and stable CO gas sensors for environmental monitoring and safety applications. [Display omitted] •SnO2/PPy/GO nanocomposite shows superior CO gas sensing performance over PPy and PPy/GO.•Enhanced sensitivity (252 at 50 ppm CO) and faster response/recovery times are achieved.•The sensor exhibits excellent linearity, selectivity, and long-term stability over 60 days.•Synergistic effects of SnO2, GO, and PPy contribute to improved sensing capabilities.