when -∆A 0 IJ = 0, the barrier for each reaction is λ/4. Consequently, the ET rate is defined by the rate constant (k 0 ET ). Our calculated k 0 ET values are very high due to the low reorganization energies caused by the small donor-acceptor distances. In some cases, we might not be able to use such an external potential because we move outside the water potential window of -1.2 V to +1.2 V. It is under this condition that electrochemical systems are prone to side reactions such as hydrogen evolution reactions and oxygen evolution reactions, which result in low performance.