context: The slurry for the electrocatalytic study was prepared by dispersing 10 mg active material and 5 mg Super P carbon in 250 μL isopropyl alcohol and 750 μL distilled water. After sonicating the solution for 15 minutes, 5 μL Nafion binder was added followed by further sonication for 30 minutes. Then, 5 μL of the slurry was drop-casted on a glassy carbon rotating ring disc electrode (RRDE). The electrocatalytic study was carried out at room temperature using a CH instrument (CHI700E) bipotentiostat using 0.1 M KOH as the electrolyte.
answer: 0.1 M KOH 