Enhanced sensitivity of ammonia sensor using graphene/polyaniline nanocomposite

In this paper, we report conductometric sensors based on graphene/PANI nanocomposites, which were synthesized using chemical oxidative polymerization, for NH3 sensing. The experimental result reveals that the graphene/PANI sensor exhibits much higher sensitivity (ca. 5 times) than that of PANI, and shows approximate linearity over a wide range of concentrations from 1 to 6400 ppm. The detection limit of graphene/PANI sensor (ca. 1 ppm) is lower than that of PANI (ca. 10 ppm) for NH3. This shows that sensitivity of graphene/PANI sensor for NH3 detection is enhanced by the graphene added into PANI. The result is partially supported by experimental data that the NH3 adsorption of quartz crystal microbalance (QCM) coated graphene/PANI is larger than that of PANI. Meanwhile, the structure and morphology of the synthesized products are characterized by Fourier transform infrared spectroscopy (FTIR), brunauer emmett tellerand (BET), ultraviolet-visible spectroscopy (UV-vis), photoluminescence (PL), X-ray photoemission spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. (c) 2013 Elsevier B.V. All rights reserved.