Fig. 1: Synthesis and characterization of NiFe-DASC.

a Schematic illustration of NiFe-DASC synthesis. b Dark-field scanning TEM and AFM (inset) images. c TEM image and d EDS elemental mapping of NiFe-DASC. e HAADF-STEM image of NiFe-DASC with some diatomic pairs being highlighted by green rectangles. f Intensity profiles of the three sites in e. g Electronic energy loss spectroscopy (EELS) of NiFe-DASC (706 eV for Fe-L3,2, 850 eV for Ni-L3,2 edges).