fig4

Figure 4. (A) Na⁺ concentration distributions and (B) Na⁺ concentration comparisons of the isotropic and anisotropic structure at the specific time in Co₉S₈/MoS₂ heterostructure. (A and B) are reprinted with permission from Ref.^[54], Copyright © 2025 Wiley; (C) Electron paramagnetic resonance (EPR) spectra of ZnS/MoS₂-600, ZnS/MoS₂-700, and ZnS/MoS₂-800; (D) Na⁺ migration paths and (E) diffusion energy barriers in ZnS/MoS₂. (C-E) are reprinted with permission from Ref.^[55], Copyright © 2025 American Chemical Society; (F) Schematic diagram of work functions of Co/FeSe and Co/Fe₃Se₄ in Co/Fe₄Se₅ heterostructure; (G) SKPM image of Co/Fe₄Se₅@C heterostructure and (H) the concerned surface potential plots. (F-H) are reprinted with permission from Ref.^[56], Copyright © 2024 Wiley. SKPM: Scanning kelvin probe force microscopy.