Photosystem II for photoelectrochemical hydrogen production.

Water is a primary source of electrons and protons for photosynthetic organisms. For the production of hydrogen through the process of mimicking natural photosynthesis, photosystem II (PSII)-based hybrid photosynthetic systems have been created, both with and without an external voltage source. In the past 30 years, various PSII immobilization techniques have been proposed, and redox polymers have been created for charge transfer from PSII. This review considers the main components of photosynthetic systems, methods for evaluating efficiency, implemented systems and the ways to improve them. Recently, low-overpotential catalysts have emerged that do not contain precious metals, which could ultimately replace Pt and Ir catalysts and make water electrolysis cheaper. However, PSII competes with semiconductor analogues that are less efficient but more stable. Methods originally created for sensors also allow for the use of PSII as a component of a photoanode. To date, charge transfer from PSII remains a bottleneck for such systems. Novel data about action mechanism of artificial electron acceptors in PSII could develop redox polymers to level out mass transport limitations. Hydrogen-producing systems based on PSII have allowed to work out processes in artificial photosynthesis, investigate its features and limitations. Supplementary Information: The online version contains supplementary material available at 10.1007/s12551-023-01139-5.