Efficient oxygen evolution on hematite at neutral pH enabled by proton-coupled electron transfer.

The rate-determining step of the oxygen evolution reaction on hematite electrodes was switched from the sequential electron/proton transfer process to the concerted proton-coupled electron transfer (CPET) process by adding pyridine derivatives to the electrolyte. By inducing the CPET process, the overpotential for oxygen evolution at neutral pH decreased by approximately 250 mV.