We have studied the adsorption of toxic gas molecules: carbon monoxide (CO), carbon dioxide (CO2) and amonia
(NH3) on penta-graphene nanoribbons (PGNRs) using first principles methods. Based on density functional theory
(DFT) and nonequilibrium Green’s function formalism (NGF), we investigated the changes of adsorption geometries, adsorption energies, charge transfer, electronic properties and electrical transmission of PGNRs when absorbing these three gas molecules. The result shows that PGNRs is a good candidate to detect CO and NH3 molecules when these two molecules are adsorbed in the region above the double bonds of PGNRs. More interestingly, PGNRs when adsorbing CO and NH3 molecules shows a significant difference of transmission coefficients close to the Fermi level compared to that of pure PGNRs. These results opens a new opportunity to develop nanoscale gas sensor using penta-graphene nanoribbon base materials.