Fig. 4: Experimental and theoretical verification of the OER mechanism for CoOOH.

a Comparison of the OER performance of CoOOH in different electrolytes (pH = ~13, 7, and 1) at 30 °C. The inset shows the onset potential for OER at log[j (A g⁻¹)] = 0. The Tafel plots collected at other temperatures are shown in Supplementary Fig. 17. b In each electrolyte, log[j (A g⁻¹)] at the corresponding onset potential is plotted against 1000/T to extract the apparent activation energy E_app and the pre-exponential factor A_app, as summarized in Supplementary Table 4. The inset shows the linear correlation between the E_app and log[A_app (A g⁻¹)]. The error bars were obtained from fitting. c Scheme of reaction intermediates in an oxide path mechanism (OPM) pathway. d The energy diagram for the OPM pathway in different pH environments. The results were calculated with an electrode potential of U = 1.23 V. e Comparison of the apparent activation energy E_app in (b) with the calculated energy for the OO coupling (i.e., intermediate III) in (d). Source data are provided as a Source data file.