Figure 4.

(a) Cyclic voltammetry curves of untreated polycrystalline Ag (blue line) and AE-Ag (4.9 μm) (red line) in argon-purged 0.1 M KOH at room temperature with a sweep rate of 50 mV/s. (b) Tafel plots of the CO partial current density for polycrystalline Ag and AE-Ag (4.9 μm). (c) Bicarbonate concentration at constant potentials of AE-Ag. (d) Charge transfer resistance at various overpotentials. The inset shows the equivalent circuit for the metal/solution interface (R_ct, R_s, CPE and W_s are charge transfer resistance, solution resistance, constant phase element, and Warburg-short circuit terminus, respectively).