▎ 摘　　要

The covalent functionalization of graphene with nitrene radicals has been investigated employing first principles calculations. Perfect graphene is very reactive against nitrene radicals and the binding energy per NH group is significantly increased when the nitrene groups are agglomerated. For bilayer graphene, we determined that the presence of a second layer does not affect the reactivity of the upper layer from a thermodynamical stand point. High levels of functionalization are needed to open a band gap in nitrene-modified graphene. At the LDA, GGA, LDA+U and HSE06 levels, we did not observe band gap opening even for the addition of one NH group per 32 carbons. This result is in contrast with a recent experimental study that attributed the band gap opening of epitaxial graphene to the adsorption of one nitrene radical per 53 carbon atoms. The small amount of adsorbed nitrene radicals is also in contrast with our results that predicted a large reactivity. We attribute this discrepancy to the large size of trimethylsilane that inhibited the agglomeration of nitrene radicals. Thus, it is possible to control the number of nitrene groups added just by varying the size of the functional group attached to nitrogen. For small functional groups like NH, it is feasible that the synthesis of 100% functionalized graphene is feasible because the binding energy per NH is duplicated with respect to the isolated addition. The addition of NH groups to graphene is more favorable when the functionalized CC bonds are broken. However, the structure with the disrupted CC bonds may prove difficult to synthesize because the break of CC bonds is not favorable at lower levels of functionalization.