fig8

Figure 8. (A) Scheme of the low-temperature calcining procedure for Cu-CD catalysts; (B) Large-field of view and (C) magnified view of TEM images; (D) Relatively large-field of view and e typical view of HAADF-STEM images of distributed single Cu atoms in carbon dots. Yellow circles in (E) indicate typical single Cu atoms; (F) FE and current density of Cu-CDs; (G) Stability test of Cu-CDs and CuPc at their highest ECR FE potentials. [Reproduced with permission^[87]. Copyright 2021, The Author(s)]; (H) Structural schematic diagram of Cu SACs N CQDs electrocatalyst; (I) Faraday efficiency at different potential of Cu-SACs N CQDs; (J, K) HAADF-STEM image of all the Cu species on the carbon-dots Cu-N-CQDs (scale bar: 2nm). (Reproduced with permission^[103]. Copyright 2024, Elsevier B.V.). HAADF-STEM: High-angle annular dark-field scanning transmission electron microscopy; FE: Faraday efficiency; SACs: Single-atom catalysts; TEM: Transmission electron microscope; CQDs: Carbon quantum dots.