It is necessary to consider two events when computing the standard ET rate constant, k 0 ET (cm/s). (i) In experiments, a range of potentials about -∆A 0 IJ /e is applied for transferring electron from the electrode to the electrolyte and vice versa. Thus, while the minima of the I and J curves are brought to the same energy level, i.e. ∆A 0 IJ = 0, indicating that oxidation and reduction reactions are symmetric, i.e. the transfer coefficient is 0.5. (ii) The resultant rate can also be defined as the integration of the transfer rates over a range of donor-acceptor distances. Taken together, the k 0 ET expresses an interfacial flux of electrons between the electrode and the electrolyte, which can be written as: