DFT Study of NO Adsorption onto the Surface of M-Decorated Graphene Oxide (M = Mg, Cu or Ag).

In order to reduce the harm of nitrous oxide (NO) on the environment, it is very important to find an effective way to capture and decompose this nitrous oxide. Based on the density functional theory (DFT), the adsorption mechanism of NO on the surfaces of M-decorated (M = Mg, Cu or Ag) graphene oxide (GO) was studied in this paper. The results show that the effects of NO adsorbed onto the surfaces of Mg-GO by O-end and Cu-GO by N-end are favorable among all of the adsorption types studied, whose adsorption energies are -1.40 eV and -1.47 eV, respectively. Both adsorption manners belong to chemisorption. For Ag-GO, however, both the adsorption strength and electron transfer with the NO molecule are relatively weak, indicating it may not be promising for NO removal. Moreover, when Gibbs free energy analyses were applied for the two adsorption types on Mg-GO by O-end and Cu-GO by N-end, it was found that the lowest temperatures required to undergo a chemisorption process are 209 °C and 338 °C, respectively. After being adsorbed onto the surface of Mg-GO by O-end, the NO molecule will decompose into an N molecule and an active oxygen atom. Because of containing active oxygen atom, the structure O-Mg-GO has strong oxidizability, and can be reduced to Mg-GO. Therefore, Mg-GO can be used as a catalyst for NO adsorption and decomposition. Cu-GO can be used as a candidate material for its strong adsorption to NO.