To effectively prevent and control hazardous gases and enable rapid detection and monitoring of environmental pollutants, gas sensors have received significant attention in recent years as a powerful platform for many applications. Among various gases, ammonia is one of the most hazardous materials in industrial use and needs effective monitoring. This study aims to demonstrate the gas sensing capability of nanocomposites utilizing an in-situ polymerization of polyaniline holding different carbon-based nanomaterials, including reduced graphene oxide (rGO), graphene oxide (GO), and carbon nanotubes (CNT). GO was synthesized by using the modified Hummer's method. Hydrothermal method is used for reducing graphene oxide, and chemical vapor deposition method was employed to synthesize the CNT. Carbon-based nanomaterials/polyaniline nanocomposites were then drop casted on a microwave resonator. The cost-effective microwave resonator demonstrated the detection of a wide range of ammonia gas concentrations (5-100 ppm) in a 3-15 min interval. Different loading levels from 0.5 to 10 wt.% of nanofillers were investigated for their optimum sensing response to ammonia gas. We noticeably found out that a higher sensing response was obtained at lower loading levels for rGO and CNT than GO. The results was shown that the sensitivity of rGO(0.5%)-PANI, CNT(2%)-PANI, and GO(10%)-PANI are 2.99, 2.29, and 2.26% dB/ppm, respectively, higher than polyaniline alone. In brief, this study corroborates the potential of microwave resonators based on carbon-based nanomaterials/polyaniline as versatile portable, contactless gas sensors.

Ammonia gas sensing of carbon-based microwave gas sensors: A comparative study

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.