Polyaniline Composites Containing Eco-Friendly Biomass Carbon from Agricultural-Waste Coconut Husk for Enhancing Gas Sensor Performance in Hydrogen Sulfide Detection

Abstract

Hydrogen sulfide, a colorless, flammable gas with a distinct rotten egg odor, poses severe health risks in industrial settings. Sensing hydrogen sulfide is crucial for safeguarding worker safety and preventing potential accidents. This study investigated the gas-sensing performance of an electroactive polymer (i.e., polyaniline, PANI) and its composites with active carbon (AC) (i.e., PANI-AC1 and PANI-AC3) toward H2S at room temperature. PANI-AC composites-coated IDE gas sensors were fabricated and their capability of detecting H2S at concentrations ranging from 1 ppm to 30 ppm was tested. The superior gas-sensing performance of the PANI-AC composites can be attributed to the increased surface area of the materials, which provided increased active sites for doping processes and enhanced the sensing capability of the composites. Specifically, the incorporation of AC in the PANI matrix resulted in a substantial improvement in the doping process, which led to stronger gas-sensing responses with higher repeatability and higher stability toward H2S compared to the neat PANI-coated IDE sensor. Furthermore, the as-prepared IDE gas sensor exhibited the best sensing response toward H2S at 60% RH. The use of agricultural-waste coconut husk for the synthesis of these high-performance gas-sensing materials promotes sustainable and eco-friendly practices while improving the detection and monitoring of H2S gas in industrial settings.

Recent Advances in Conductive Polymers-Based Electrochemical Sensors for Biomedical and Environmental Applications

“…It is hypothesized that the enhanced response of the PUU-AC composite to H 2 S can be attributed to its elevated surface area and abundant reaction sites, which facilitate gas diffusion, adsorption, and electron transfer. The successful fabrication of interdigitated electrode (IDE) coated with PANI-AC composites enables the homoplastic detection of H 2 S [ 174 ]. The PANI was synthesized through oxidative coupling polymerization of aniline monomers, while the AC was obtained by calcinating coconut husks from agricultural waste at 800 °C with ZnCl 2 as a catalyst.…”