DFT Study of N<sub>2</sub>O Adsorption onto the Surface of M-Decorated Graphene Oxide (M = Mg, Cu or Ag)

oleh: Zhong Liu, Xi-ren Cheng, Yi-min Yang, Hong-zhang Jia, Bao-quan Bai, Li Zhao

Format: Article
Diterbitkan: MDPI AG 2019-08-01

Deskripsi

In order to reduce the harm of nitrous oxide (N<sub>2</sub>O) 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 N<sub>2</sub>O 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 N<sub>2</sub>O adsorbed onto the surfaces of Mg&#8722;GO by O-end and Cu&#8722;GO by N-end are favorable among all of the adsorption types studied, whose adsorption energies are &#8722;1.40 eV and &#8722;1.47 eV, respectively. Both adsorption manners belong to chemisorption. For Ag&#8722;GO, however, both the adsorption strength and electron transfer with the N<sub>2</sub>O molecule are relatively weak, indicating it may not be promising for N<sub>2</sub>O removal. Moreover, when Gibbs free energy analyses were applied for the two adsorption types on Mg&#8722;GO by O-end and Cu&#8722;GO by N-end, it was found that the lowest temperatures required to undergo a chemisorption process are 209 &#176;C and 338 &#176;C, respectively. After being adsorbed onto the surface of Mg&#8722;GO by O-end, the N<sub>2</sub>O molecule will decompose into an N<sub>2</sub> molecule and an active oxygen atom. Because of containing active oxygen atom, the structure O&#8722;Mg&#8722;GO has strong oxidizability, and can be reduced to Mg&#8722;GO. Therefore, Mg&#8722;GO can be used as a catalyst for N<sub>2</sub>O adsorption and decomposition. Cu&#8722;GO can be used as a candidate material for its strong adsorption to N<sub>2</sub>O.