Exploring the Gas Sensing Potential of Cross-Linked Asphaltene: A Promising Application of an Affordable Material

Abstract

In recent years, there has been significant research interest in carbon-based nanomaterials as promising candidates for sensing technologies. Herein, we present the first utilization of asphaltenes as an affordable, cost-efficient carbon-based material for gas sensing applications. Asphaltenes, derived from various oil sources, are subjected to facile cross-linking reactions to produce nanoporous carbon materials, where the asphaltene molecules from different layers are interconnected via covalent bonds. The characterization results of these cross-linked asphaltenes revealed substantial enhancement in their specific surface area and surface functionality. Quartz crystal microbalance sensors with sensing films derived from various asphaltene samples were prepared to detect different ethanol concentrations at room temperature. All the cross-linked asphaltene samples showed a significant enhancement in the sensing response (up to 430%) compared to that of their respective raw parent samples. Such a response of the cross-linked asphaltene samples was comparable to that obtained from graphene oxide. The sensor based on cross-linked asphaltenes demonstrated good linearity, with a response time of approximately 2.4 min, a recovery time of around 8 min, and an excellent response repeatability. After 30 days, the sensor based on cross-linked asphaltenes showed approximately 40% reduction in its response, suggesting long-term aging. This decline is partially attributed to the observed swelling. The current study opens the door to a deeper exploration of asphaltenes and highlights their potential as promising candidates for sensing applications.

The Asphaltenes: State-of-the-Art Applications and Future Perspectives in Materials Science

“…The heightened response observed in the cross-linked asphaltene samples was on par with that attained from graphene oxide (GO)-based sensor (Figure (a)). The improvement in sensing performance of the cross-linked asphaltenes was explained by their enhanced surface functionality and swelling capability, besides larger specific surface area and porosity . The QCM sensor utilizing cross-linked asphaltenes demonstrated an almost linear response, favorable response-recovery times, and outstanding response repeatability during cyclic exposure (Figure (b–d)).…”

“…Although the studies mentioned above have emphasized the exceptional gas absorption capabilities of asphaltenes, their potential for application in gas sensing devices must still be explored. Very recently, Hejazi et al reported the first employment of asphaltenes in gas-sensing applications. They fabricated various quartz crystal microbalance (QCM) sensors with sensing films obtained from different raw and cross-linked asphaltene samples developed in the work of Ok and Samuel .…”

“…Sensing performance of the cross-linked version of sample #3, originally extracted from a light crude oil with an °API of 37.88: Linear fitting of the response to varying concentrations of ethanol (b); response-recovery times toward 2000 ppm ethanol (c); repeatability in six consecutive sensing cycles of exposure to 2000 ppm ethanol (d); long-term stability of sensor (e); response to different targets (f). Reprinted with permission from Hejazi et al Copyright 2024 American Chemical Society.…”