Figure 5.

SEM image (a) and the corresponding elemental mapping images (b) of selected silver–cobalt composite oxide. Current density at 1.7 V_RHE and applied potential at 10 mA cm^–2 before and after 50 CV for pristine Co₃O₄ and Ag–Co oxides in a 1 M KOH electrolyte with trace Fe impurities (c) and Fe-free 1 M KOH after purification (d). Current density at 1.7 V_RHE of selected Co₈Ag oxides in purified 1 M KOH with varying Fe concentration with the controlled addition of Fe (e). Reproduced with permission from ref (2). Copyright 2020 Wiley.