Next, two CVs demonstrating the O2 •-/HO2 • scavenging by PiceH4 and RsvH3 (Figures cycles, indicating that pa6 was derived from the product of a series of PCET reactions triggered by the electrogeneration of O2 •-, i.e., the pc6/pa6 peaks plausibly originated from a reversible redox of a product of the PCET from PiceH4 to O2 •-. The PCET involves the initial PT (Equation ( )) followed by ET (Equation ( )) from the deprotonated anion (PiceH3 -) to HO2 • , forming a substrate radical (PiceH3 • ) and a hydroperoxyl anion (HO2 -). In addition, Figure demonstrates the effects of scan rates on the second cycle of CV. As the scan rate increases, the bielectronic cathodic peak (pc6 on pc1 in the both of first and second cycles) becomes smaller, because the slow diffusion of substances in the electrode surface usually limits the electrode process. Nevertheless, the pc6/pa6 couple in the second cycle becomes larger. These CV appearances with scan rate dependency demonstrated that the reversible redox (pc6/pa6) appeared in the second cycle scan that derived from a quinoid radical as a product of the PCET.