Fig. 2: Electrochemical deposition mechanism.
From: Electrochemical deposition as a universal route for fabricating single-atom catalysts
a, b Schematic of cathodic (a) and anodic (b) deposition of Ir species. The yellow, green, red, and white spheres represent Ir, Cl, O, and H atoms, respectively. A standard three-electrode system was used, with Co(OH)2 nanosheets loaded on a glassy carbon electrode as the working electrode (WE), a carbon rod as the counter electrode (CE), and an Ag/AgCl electrode as the reference electrode (RE). c, d Ir mass loadings as a function of Ir concentration in the 1 M KOH electrolyte for cathodic (c) and anodic (d) deposition. The scanning cycle number was kept at ten for cathodic deposition and three for anodic deposition. The color gradient from yellow to white indicates the transition from single atoms to clusters with increasing Ir concentration. 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.
