Adsorption behavior of toxic nitrogen-containing gas molecules on GeC monolayer for the sensitive and reusable gas sensors: first-principles calculations

Abstract Using the first-principles calculations, the gas sensing properties of GeC monolayer are analyzed to explore the possibilities in the toxic nitrogen-containing molecular sensors to detect NH 3 , NO 2 and NO molecules. The adsorption behavior is computed under different stable adsorption configurations. NH 3 is physically adsorbed on GeC monolayer with modest adsorption energies (E ads = −0.487 eV). NO 2 is chemisorbed on GeC monolayer with E ads of −0.770 eV. NO is either physisorbed or chemisorbed on GeC monolayer with E ads of −0.437 eV or −0.605 eV depending on the stable adsorption configurations. NO 2 and NO molecule dramatically change the electronic properties of GeC monolayer, while NH 3 molecule barely modifies those of GeC monolayer. Because of the change in the electric conductivity, the descending order of the sensitivity is NO 2 > NO > NH 3 . Finally, the quick recovery times are found for all molecules which determine the worth of reusability of a sensing material.