This study investigates the effects of carbon monoxide (CO) and nitric oxide (NO) on the structural characteristics of pristine and doped graphene using density functional theory (DFT) calculations based on the Perdew-Burke-Ernzerh (PBE) approach within the generalized gradient approximation (GGA). Various calculations were performed to assess adsorption energies, ideal positions, charge transfer, band structures, density of states, and electronic properties.
For CO, the adsorption energies on pristine and nitrogen (N)-doped graphene were found to be −0.01 eV and −0.03 eV, respectively, while the adsorption energy on aluminium (Al)-doped graphene was significantly higher at −3.07 eV. Regarding NO, the pristine and Al-doped graphene displayed adsorption energies of −0.01 eV and −2.24 eV, respectively, whereas N-doped graphene showed a much stronger adsorption energy of −3.65 eV.
The results indicate substantial charge transfer between CO and the graphene lattice during adsorption, suggesting that Al-doped graphene is more sensitive to CO compared to pristine and N-doped graphene. In contrast, for NO adsorption, pristine and N-doped graphene demonstrated greater sensitivity than Al-doped graphene.