Fig. 2: Oxygen reduction activity of Cu/G and two Cu/CNT samples.

a ORR polarization curves, b kinetic current density curves, and c E1/2, Eonset, MA, and TOF at 0.85 V.

a ORR polarization curves, b kinetic current density curves, and c E1/2, Eonset, MA, and TOF at 0.85 V.