What Can be Learned from Proton Relays in Photosystem II toward Complete Biomimicking of Oxygen Evolution Reaction Electrocatalysis?

Abstract

AbstractHow to put together a comprehensive water oxidation design is the long‐term problem for the generation of sustainable fuels. In nature, plants are equipped with a complex mechanism (the Calvin cycle) in the stroma that, over the billions of years, efficiently takes CO2 and converts it to sugar. This reductive process needs electrons from an oxygen‐evolving complex (OEC) in the core of photosystem II, where a water oxidation reaction (WOR) releases molecular oxygen. The initial function of proton relays in natural WOR happens when Tyrosine Yz is oxidized by light harvested P680 through a proton‐coupled electron transfer reaction. The second and main one, is composed of water‐included polypeptide channels from and to CaMn4O5. These channels were created utilizing hydrogen‐bonded networks (HBN). HBN is crucial in providing water substrate and removing the released protons to prevent the accumulation of protons and preserve the stability of the catalytic center. This concept summarizes the challenges in employing biomimicry to create artificial leaves from the viewpoint of proton relays, with the main purpose being providing structural functionality to assist the quick proton hopping.