Fig. 3
From: Anchoring zero valence single atoms of nickel and iron on graphdiyne for hydrogen evolution
XAS studies and size distribution. a Additional HAADF-STEM image of Ni/GD [inset: size distribution of Ni atoms counted from HAADF-STEM images (>560 Ni atoms considered, the most probable value is 1.23 ± 0.40 Å)]. Scale bar, 2 nm. b STEM elemental mapping of Ni/GD. Scale bar, 200 nm. c Ex situ EXAFS spectra of Ni/GD and Ni foil at the Ni K-edge. d Additional HAADF-STEM image of Fe/GD [inset: size distribution of Fe atoms counted from HAADF-STEM images (>1070 Fe atoms considered, the most probable value is 1.02 ± 0.33 Å)]. Scale bar, 2 nm. e STEM elemental mapping of Fe/GD. Scale bar, 200 nm. f Ex situ EXAFS spectra of Fe/GD and Fe foil at the Fe K-edge. All atoms counted in the HAADF-STEM images were well separated from their neighbors
