Graphene-based Nanocomposite Containing Au, Sb, and Si to Enhance the Sensitivity of Carbon-monoxide and Ammonia Gas Sensors

Carbon monoxide (CO) and ammonia (NH₃) are highly toxic gases that pose serious health risks. The development of gas sensors capable of detecting low concentrations of these gases at room temperature is therefore of great importance. In this work, we report the synthesis and characterization of a graphene-based nanocomposite modified with gold (Au), antimony oxide (Sb₂O₃), and silica (SiO ₂ ), aimed at enhancing the sensitivity, and response/recovery dynamics toward CO and NH₃. For synthesis of graphene oxide (GO) a modified Hummers’ method was applied. Gold, antimony trioxide and silica nanoparticles were prepared through hydrothermal, sonochemical and sol-gel methods respectively. The structural and morphological properties of as-prepared nanostructures were investigated using SEM, XRD, FT-IR, EXD and MAP Analysis. Gas sensing tests reveal that the nanocomposites exhibit significantly improved sensitivity to both CO and NH₃, with lower detection limits, sharper response and recovery times compared to pure graphene oxide. As the best result GO/Au showed a change of 60% in response time to CO and around 42% to NH ₃ , besides an improvement of 52% for recovery time from CO gas and 54% from NH ₃ gas in contrast to pure GO. These findings suggest that all three nanocomposites present a promising pathway toward high-performance, room-temperature CO and NH₃ sensors with the advantage of GO/Au nanocomposite.