Liu Zhong, Cheng Xi-Ren, Yang Yi-Min, Jia Hong-Zhang, Bai Bao-Quan, Zhao Li
School of Energy Power and Mechanical Engineering, North China Electric Power University, Beijing 102206, China.
National Engineering Laboratory for Biomass Power Generation Equipment, North China Electric Power University, Beijing 102206, China.
Materials (Basel). 2019 Aug 16;12(16):2611. doi: 10.3390/ma12162611.
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.
为了减少一氧化二氮（NO）对环境的危害，找到一种有效捕获和分解这种一氧化二氮的方法非常重要。基于密度泛函理论（DFT），本文研究了NO在M修饰（M = Mg、Cu或Ag）的氧化石墨烯（GO）表面的吸附机理。结果表明，在所研究的所有吸附类型中，NO通过O端吸附在Mg-GO表面以及通过N端吸附在Cu-GO表面的效果较好，其吸附能分别为-1.40 eV和-1.47 eV。这两种吸附方式均属于化学吸附。然而，对于Ag-GO，其与NO分子的吸附强度和电子转移都相对较弱，表明其在去除NO方面可能没有前景。此外，当对Mg-GO通过O端和Cu-GO通过N端的两种吸附类型进行吉布斯自由能分析时，发现发生化学吸附过程所需的最低温度分别为209℃和338℃。NO分子通过O端吸附在Mg-GO表面后，会分解为一个N分子和一个活性氧原子。由于含有活性氧原子，O-Mg-GO结构具有很强的氧化性，并且可以还原为Mg-GO。因此，Mg-GO可作为NO吸附和分解的催化剂。Cu-GO因其对NO的强吸附性可作为候选材料。
