Fig. 3: OER performance of TMOOH-xCO₃^2-.

a Schematic illustration of all TMOOH-xCO₃^2- model catalysts; b comparison of the onset potential and Tafel slope of TMOOH-xCO₃^2- obtained from LSV and MSLSV; c–e comparison of the η₁₀ (the overpotential at 10 mA cm⁻²) values for pristine TMOOH-xCO₃^2- and those after being soaked in 0.1 M KOH aqueous solution with and without bias at 1.6 V vs. RHE for 12 h. All measurements were conducted in 0.1 M KOH at 25 °C with a scan rate of 5 mV s^-1 and a solution resistance (R_s) of 12.2 ± 0.5 Ω. Box plots display the median (centerline), the interquartile range (IQR; box bounds from the 25th to the 75th percentile), and the whiskers encompassing 1.5× IQR from the quartiles. All points outside the whiskers are defined as outliers.