fig2

Figure 2. (A-C) The preparation of DACs by ALD and AC HAADF-STEM images of Pt-Ru pairs. Reproduced with permission from Ref.^[43]. Copyright 2019, Nature Publishing Group; (D) The schematic synthesis of Pt₁Ni₁/C₃N₄ and Pt₁+Ni₁/C₃N₄ dimers; (E) AC HAADF-STEM images and structural models; (D-E) Reproduced with permission from Ref.^[64]. Copyright 2022, Wiley-VCH. DACs: Dual-atom catalysts; ALD: atomic layer deposition; AC HAADF-STEM: aberration-corrected high-angle annular dark-field scanning transmission electron microscopy.