Composite nanoarchitectonics with reduced-graphene oxide and polyaniline for a highly responsive and selective sensing of methanol vapors

Abstract

In an approach to develop room temperature, highly responsive and selective methanol gas sensor, reduced graphene oxide-polyaniline nanocomposites have been successfully synthesized through simple chemistry based chemical oxidative synthesis process in the presence of camphor sulfonic acid. Field emission scanning electron microscopy, Raman spectroscopy, and X-ray diffraction, respectively, were used to examine the morphological, vibrational, and structural characteristics of synthesized samples systematically. The morphology of prepared samples was observed as nanoparticles and structure as semi-crystalline in nature. Raman spectra of synthesized samples exhibit all essential bands that confirm the growth of expected samples. Thereafter, these samples were studied as sensors for the detection of 50, 100, 150 and 200 ppm levels of methanol vapors. It was found that 8 wt% reduced graphene oxide doped polyaniline composite exhibits the highest response (%) i.e., 52% at 200 ppm. Furthermore, these sample showed good stability even after 180 days of fabrications. To understand the response of these composites, a sensing mechanism is also discussed. Our results shows that reduced graphene oxide doped polyaniline-based gas sensors showed high response, selectively towards Methanol vapors. Moreover, prepared sensors showed appreciable stability, reproducibility and repeatability making them suitable candidates for commercial production of methanol vapor sensors.