fig5

Figure 5. (A) EELS of the Fe-L edge and O-K edge of A-FeSnO_x, A-FeO_x and C-FeSnO_x; XPS spectra of C-FeO_x, A-FeO_x, C-FeSnO_x, and A-FeSnO_x: Fe 2p, corresponding +3/+2 valence ratio of Fe, Sn 3d, O 1s. (Reproduced with permission^[27]. Copyright 2024, Wiley); (B) EPR spectroscopy analysis of A/Co₃-Fe ONS membrane. (Reproduced with permission^[73]. Copyright 2024, Elsevier); (C) EXAFS spectra of Co and Fe K-edge for CoFeO@BP together with various references. (Reproduced with permission^[74]. Copyright 2020, Wiley). EELS: Electron energy loss spectroscopy; XPS: X-ray photoelectron spectroscopy; EPR: electron paramagnetic resonance; ONS: oxide nanosheets; EXAFS: extended X-ray absorption fine structure.