fig2

Figure 2. (A) XRD pattern of Ni₃N-Co₂N_0.67/NC. (B and C) SEM images of Ni₃N-Co₂N_0.67/NC. (D) TEM image. (E and F) high-resolution TEM image (Inset: SAED image). (G) high-angle annular dark field TEM image. (H and L) the EDS mapping images of Ni, Co, C, N, and O elements. (M) EDS diagram. XRD: X-ray diffraction; SEM: scanning electron microscopy; TEM: transmission electron microscopy; SAED: selected area electron diffraction.