Fig. 5: SEM, AFM, room temperature EPR spectrum and XPS spectra characterizations of N-CNS.

a SEM image of bulk N-CNS, scale bar 4 μm; inset, AFM image of N-CNS, scale bar 6 Å. b Room temperature EPR spectrum of solid powder. c C 1s and d N 1s XPS spectra of N-CNS.