fig5
Figure 5. (A, B) Schematic illustration of the formation of Fe single atoms. (C) SEM, (D) TEM, (E) HRTEM, (F) elemental mapping and (G, H) AC-HAADF-STEM images of Fe-Nx ISAs/GHSs. TEM: Transmission electron microscopy; HRTEM: high resolution TEM; AC-HAADF-STEM: aberration-corrected high angle annular dark field scanning transmission electron microscopy.
