fig3

Figure 3. (A) Polarization curves of the SWNT (orange), the SWNT activated for 4 h (red), GR (blue), GR activated for 4 h (green) and 16 h (cyan), and Pt/C (black). (B) Structure diagram of the SWNT with isolated, dispersed Pt; reproduced from Ref.^[45] with permission from the American Chemical Society. (C) Schematic diagram of the potential-cycling synthesis method process. Reproduced from Ref.^[46] with permission from Wiley-VCH. Schematic of cathodic (D) and anodic (E) deposition of Ir species; The yellow, green, red, and white spheres represent Ir, Cl, O, and H atoms, respectively. Ir mass loadings as a function of Ir concentration in the 1 M KOH electrolyte for anodic (F) deposition. The scanning cycle number was kept at ten for cathodic deposition and three for anodic deposition. The inset images correspond to the HAADF-STEM images of the samples obtained at a certain concentration. The areas in white circles indicate the agglomerations of single atoms to form clusters. Reproduced from Ref.^[47] with permission from Springer Nature.