One-step electrosynthesis of a nanocomposite of functionalized graphene and polypyrrole for enhanced room-temperature nitrogen oxide sensing

Abstract

Due to the numerous challenges related to selectivity, sensitivity, stability, and operation at standard room temperature, improving the environmental detection of nitrogen oxide presents a considerable defy in the development of novel promising structures in chemical detection. In this study, a new series of p-type heterojunction nanocomposites based on electrodeposited polypyrrole (PPy) doped with n-dodecylbenzene sulphonate and either reduced graphene oxide (PPy/RedGO) or reduced graphene oxide functionalized using aryl 4-carboxybenzene diazonium salt (PPy/RedGO-arylCOOH) was synthetized using a one-step chronoamperometric process. The influence of functionalized graphene incorporation on the structural, morphological, and sensory performances of the PPy film was investigated. Its sensitivity and reactivity to NO₂ sensing were studied. The structural data confirms that PPy/RedGO-arylCOOH film is a homogeneous nanocomposite with improved crystalline ordering. It shows optimal NO₂ sensing properties compared to the PPy/RedGO composite in terms of sensitivity (0.87 ppm⁻¹), detection limit (2 ppm), response time of 29 s, recovery time of 40 s and reproducibility at room temperature.