Enhanced trace NO2 gas sensing with functionalized graphene-based nanofibers

Abstract

The development of trace nitrogen dioxide (NO2) gas sensors has recently garnered widespread attention. This interest arises not only from the demand for industrial production and environmental monitoring but, more importantly, due to the inherent health hazards associated with trace NO2 levels. In this study, we introduce a graphene-based nanofiber functionalized with a conductive polymer and metal nanoparticle, namely the AgPGNFs, for trace NO2 detection. We employ a combination of supramolecular assembly and oriented lyophilization technique to manufacture these nanofibers. These nanofibers harness the synergistic effects of functionalization and three-dimensional structuring involving graphene, conductive polymers, and metal nanoparticles, significantly enhancing NO2 adsorption and charge variation to improve sensing performance. Consequently, the as-prepared sensor exhibits high sensitivity to NO2, rapid response and recovery speed, excellent gas selectivity and stability, and notably, a low limit of detection of 20 ppb. This work underscores the potential of a new approach for designing advanced trace gas sensors.