Pt-doped armchair graphene nanoribbon as a promising gas sensor for CO and CO₂: DFT study

In this work, four armchair graphene nanoribbon (AGNR) based sensor materials were built using Atomistic ToolKit Virtual NanoLab (ATK-VNL) and utilized to detect carbon monoxide (CO) and carbon dioxide (CO₂) gases. First, the effect of passivating AGNR on the sensing performance toward CO and CO₂ gases has been investigated, where AGNR was passivated with hydrogen (H-AGNR) and nitrogen (N-AGNR). The obtained results reflected no significant changes in the adsorption parameters of CO and CO₂ molecules on H-AGNR and NAGNR. Particularly, the adsorption energies between H-AGNR and N-AGNR systems and CO were found to be − 0.446 and − 0.436 eV, while for the case of CO₂, the adsorption energies were found to be − 0.426 and − 0.432 eV, respectively. To enhance the sensing performance, both H-AGNR and N-AGNR systems were doped with platinum (Pt) forming another two systems: Pt–H-AGNR, and Pt–N-AGNR. After doping, the results revealed a significant increase in the adsorption energy to almost 9 times than the non-doped systems for the cases of CO on Pt–N-AGNR as well as CO₂ on both Pt–H-AGNR and Pt–N-AGNR. Moreover, an increase of almost 13 times was observed in the adsorption energy for the case of CO on Pt–H-AGNR. Besides to the adsorption energy (E_ads), the adsorption distance ((D), charge transfer (ΔQ), the density of states (DOS), as well as the band structure have been examined to confirm the adsorption of CO and CO₂ on the four systems.

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Published in: Physica E: Low-dimensional Systems and Nanostructures
License: http://creativecommons.org/licenses/by/4.0/
See article on publisher's website: https://dx.doi.org/10.1016/j.physe.2020.114418