fig3
Figure 3. SEM images of (A) CoFe-MOF and (B) CoFe/Co@NC. (C and D) TEM and (E and F) HRTEM images of CoFe/Co@NC. SEM: Scanning electron microscopy; MOF: metal-organic framework; NC: nitrogen-doped carbon; TEM: transmission electron microscope; HRTEM: high-resolution TEM.
