The effect of ZrOx modification of graphene nanoribbon on its adsorption for NOx: A DFT investigation

Emission of anthropogenic short-lived gases that are chemically reactive including NO_x (x=1 and 2) and CO has a well-known influence on altering the climate chemistry of the troposphere layer, and hence the abundance of many greenhouse gases such as HFCs, O₃, and CH₄. Therefore, the progress in production of exceedingly selective gases detectors to monitor and control their content in the ambient is crucial to track their emission. The effect of alteration of graphene nanoribbon of armchair structure (AGNR) by zirconium (Zr) metal as well as its oxides on the adsorption for NO_x gases is examined is this work. First principles density functional theory computations (DFT) are employed to explore the adsorption energy (E_d) and length (D), band structure, charge transferred (ΔQ) as well as density of states (DOS) of pure and modified AGNR structures using ZrO_x where x=0,1, and 2. Herein, ZrO_x is introduced to AGNR by two pathways: doping (substitution of carbon atom(s)), and decoration (addition on top of surface). The outcomes of this study demonstrate extraordinary improvement of NO_x adsorption on the modified AGNR structures. Though the adsorption energy of NO_x gas is boosted, generally, for AGNR structures due to modification with ZrO_x, the doped structures have greater adsorption energy when compared with the decoration ones. The highest adsorption energy for NO_x gases is for AGNR doped using ZrO₂, followed by that for AGNR doped using ZrO. Herein, the adsorption energy of AGNR doped using ZrO₂ for NO increases 26.9 times while it increases 19.6 times for NO₂ as compared with those of the pure structure. Hence, modified AGNR structures using ZrO_x may be implemented for applied field sensors for environmental applications to detect and control NO_x emission.

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Published in: Materials Chemistry and Physics
License: http://creativecommons.org/licenses/by/4.0/
See article on publisher's website: https://dx.doi.org/10.1016/j.matchemphys.2022.126693