and was more evident with increasingly positive scan limits in the CV (Fig. ). These assignments are in agreement with previous observations of Co-oxides the literature 26,27 while Feoxides typically do not show such redox behavior under these conditions 28 . The oxidation peak of the Co(III/IV) redox couple was not as visible as it was overshadowed by the catalytic current which initiated alongside of the Co(III/IV) oxidation. This signifies that Co(IV) was likely involved in the OER catalytic cycle. We note that there is probably a surface restructuration that occurs as the redox behavior of the 1 st CV differs from the 2 nd , though no further changes occur afterward (Fig. ).