Abstract
Abstract In this study, density functional theory (DFT) has been used to build armchair graphene nanoribbon (AGNR) gas sensor and study its capacity to detect carbon monoxide (CO), carbon dioxide (CO2), and sulfur dioxide (SO2) gases. The adsorption of these gases on AGNR was confirmed based on the adsorption energy (Eads), adsorption distance (D), charge transfer (ΔQ), density of states (DOS), and band structure. In order to improve the adsorption capacity, three different modified AGNR systems have been built. AGNR was first functionalized with epoxy (-O-) group (AGNR-O), then with hydroxyl (-OH) group (AGNR-OH), and finally with (-O-) along with (-OH) groups (AGNR-O-OH). Before modification, the adsorption energies have been found to be −0.260, −0.145, and −0.196 eV due to the adsorption of CO, CO2, and SO2, respectively. After modification, the adsorption energy increased remarkably to −0.538 and −0.767 eV for the cases of AGNR-O-OH-CO2 and AGNR-O-OH-SO2, respectively. Indicating that functionalizing the surface of AGNR can improve significantly its performance for the field of gas sensing.
Highlights
Over the past few years, the development of low cost, reliable and effective toxic gas sensors becomes of great interest on many levels extending from medical to industrial applications
The highest charge transfer is observed for the case of armchair graphene nanoribbon (AGNR)-carbon monoxide (CO) with À 0.019 e
The results show that the adsorption parameters of AGNR toward CO and SO2 are improved after the functionalization with -O- group, while no significant changes are observed after the adsorption of CO2
Summary
Over the past few years, the development of low cost, reliable and effective toxic gas sensors becomes of great interest on many levels extending from medical to industrial applications. Carbon monoxide (CO), carbon dioxide (CO2), and sulfur dioxide (SO2) are seriously harmful to humans. The colorless, odorless, tasteless, and toxic CO gas is generated mainly during incomplete combustion of fuels such as natural gas and oil [1]. CO2 is mostly generated as a result of industrial and agriculture applications as well as the combustion of fossil fuels [3]. The development of low cost and highly sensitive sensors for CO, CO2, and SO2 is of great interest
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