Sensitive SO2 gas sensor utilizing Pt-doped graphene nanoribbon: First principles investigation

Abstract

The objective of this work is to seek a highly sensitive gas sensor for the detection of sulfur dioxide (SO2) by investigating the impacts of passivation as well as metal doping of armchair-edge graphene nanoribbon (AGNR) on the adsorption capacity. Herein, two AGNR based sensor materials for SO2 are passivated with hydrogen and nitrogen (AGNRH and AGNRN) then investigated theoretically using density functional theory (DFT). The results demonstrate that AGNRH is more sensitive to SO2 gas than AGNRN with −0.532 eV adsorption energy (Ead) and 0.05 e charge transfer (ΔQ). Furthermore, two more sensor materials are examined via doping AGNRH and AGNRN with platinum: Pt-AGNRH and Pt-AGNRN. Interestingly, the adsorption energies and charge transfer increased remarkably to −6.327 eV (almost 12 times the non-doped case) and 0.373 e, respectively, for the case of the SO2/Pt-AGNRH system. The same trend is observed as well for the case of SO2/Pt-AGNRN. The significant improvement of the adsorption parameters specifies that Pt doping has a considerable impact on enhancing the sensing performance of passivated AGNR toward the detection of SO2 gas.