From N 1s deconvolution procedure applied to the HR spectra of both N-rGO and Cu-N-rGO, we obtained two components that can be assigned to N atoms implanted in the graphene lattice, one is attributed to pyrrolic-like nitrogen (399.1–399.6 eV) and the other is due to a quaternary or graphitic configuration (400.9–401.7 eV), as already reported in our previous work9.