fig8

Figure 8. (A) K-edge XANES spectra of Fe-SAC@COF; (B) Fourier transform EXAFS spectra of Fe-SAC@COF and reference sample; (C) LSV curves of Fe-SAC@COF and reference samples in OER. The (A-C) are quoted with permission from Wang et al.^[66]; (D) AC HAADF STEM image of CoMM; (E) EELS spectrum of CoMM; (F) Mass activity of OER electrocatalyzed by cobalt-based electrodes. The (D-F) are quoted with permission from Kumar et al.^[77]; (G) Mapping images of corresponding elements of HAADF-STEM and individual Ni SAs@S/N-FCS; (H) OER polarization curve of Ni SA@S/N-FCS; (I) Corresponding Tafel slopes of RuO₂, S/N-FCS, Ni NPs@S/N-FCS and Ni SA@S /N-FCS. The (G-I) are quoted with permission from Zhao et al.^[61]; (J) FT-EXAFS curve of Ni_SA-O/Mo₂C; (K) OER polarization curve of Ni_SA-O/Mo₂C. The (J-K) are quoted with permission from Hou et al.^[78]. XANES: X-ray absorption near edge structure; EXAFS: Extended X-ray absorption fine structure; OER: Oxygen evolution reaction; AC HAADF STEM: Aberration-corrected high-angle annular dark field scanning transmission electron microscopy; CoMM: Graphenic network using melem; EELS: Electron energy loss spectroscopy; LSV: Linear sweep voltammetry; SACs: Single-atom catalysts; COF: Covalent organic framework.