fig7

Figure 7. (A) The atomic resolution HAADF-STEM image of HCM@Ni-N; (B) Ni K-edge EXAFS spectra and Fourier transform of the experimental EXAFS spectrum in K space of HCM@Ni-N; (C) Schematic band diagrams of HCM@Ni and HCM@Ni-N^[69]. Copyright 2023, Wiley; (D) Differential charge densities of CuN₂O₂ and CuN₄; (E) The limiting potentials of the products of ECR and HER on the CuN₂O₂, CuN₄, and Cu(111)^[71]. Copyright 2023, Springer Nature; (F) Schematic diagram of the preparation process of Ni-B/N-C; (G) The FT EXAFS spectra of Ni foil, NiO, NiPc, Ni-B/N-C, and Ni-N-C; (H) Coordination environment of Ni-B₁N₃ moiety; (I) Gibbs free energy diagram for ORR process of the Ni-N₄ and Ni-B₁N₃ moiety^[72]. Copyright 2023, Wiley; (J) The scaling relationships for the adsorption energy of NH^*-N₂H^* and Linear correlations between the adsorption energy of N₂H^* (E_N2H*) and limiting potential of the NRR^[73]. Copyright 2023, RSC Publishing. HAADF-STEM: High-angle annular dark field scanning transmission electron microscopy; EXAFS: extended X-ray absorption fine structure; ECR: CO₂ reduction reaction; HER: hydrogen evolution reaction; ORR: oxygen reduction reaction; NRR: nitrogen reduction reaction.