▎ 摘　　要

Exploring and evaluating the potential applications of two-dimensional graphene is an increasingly hot topic in graphene research. In this paper, by studying the adsorption of NO, N2O, and NO2 on pristine and silicon (Si)-doped graphene with density functional theory methods, we evaluated the possibility of using Si-doped graphene as a candidate to detect or reduce harmful nitrogen oxides. The results indicate that, while adsorption of the three molecules on pristine graphene is very weak, Si-doping enhances the interaction of these molecules with graphene sheet in various ways: (1) two NO molecules can be adsorbed on Si-doped graphene in a paired arrangement, while up to four NO2 molecules attach to the doped graphene with an average adsorption energy of -0.329 eV; (2) the N2O molecule can be reduced easily to the N-2 molecule, leaving an O-atom on the Si-doped graphene. Moreover, we find that adsorption of NO and NO2 leads to large changes in the electronic properties of Si-doped graphene. On the basis of these results, Si-doped graphene can be expected to be a good sensor for NO and NO2 detection, as well as a metal-free catalyst for N2O reduction.