Figure 5.

Electrochemical characterizations of single‐holed Co/NC hollow particles as an electrocatalyst for ORR. a) CV curves in N₂‐saturated and O₂‐saturated 0.1 m KOH solution with a sweep rate of 20 mV s⁻¹. b) Linear sweep voltammetry (LSV) curves of single‐holed Co/NC hollow particles and a commercial Pt/C catalyst in O₂‐saturated 0.1 m KOH solution with a sweep rate of 10 mV s⁻¹ at the rotating speed of 1600 rpm. c) Durability test in O₂‐saturated 0.1 m KOH at 0.5 V. d) Chronoamperometric responses obtained at 0.5 V in O₂‐saturated 0.1 m KOH solution (150 mL) with addition of 10 mL of methanol at the time of 2000 s.