Adsorption of diatomic gas molecules on transition-metal-decorated GeC monolayers

In this work, we study the adsorption of O₂, N₂ and NO molecules on graphene-like germanium carbide monolayers (2DGeC) decorated with transition metal (TM) atoms (Au, Ag and Cu) using density functional calculations. The results show that, in comparison with the pristine 2DGeC, the TM adatoms enhance the adsorption of these molecules, except for N₂ on Au-2DGeC and Ag-2DGeC. The largest increment of adsorption energy (E_A) for the studied molecules is found for the Cu-adatom case, followed by the Ag and Au ones, in decreasing order of E_A. Moreover, the metal-decorated 2DGeC monolayers give electronic charge to the adsorbed molecules, which weakens the molecule bond. In all the TM-decorated 2DGeC, the N₂ molecule has the smallest values of E_A, in comparison with the other studied molecules. Finally, since NO has the largest E_A in comparison with those of O₂ and N₂ on the TM-decorated 2DGeC, these nanosheets could be used as NO traps to fight air pollution.