Solar water-splitting into H2 and O2: design principles of photosystem II and hydrogenases

Abstract

This review aims at presenting the principles of water-oxidation in photosystem II and of hydrogen production by the two major classes of hydrogenases in order to facilitate application for the design of artificial catalysts for solar fuel production. W: Lubitz E: Reijerse J: Messinger W. Lubitz is director of the MPI for Bioinorganic Chemistry and a specialist in advanced EPR techniques. He has a strong interest in both water-splitting and hydrogen production. E. Reijerse is working on hydrogenases using FTIR and EPR/ENDOR spectroscopies. J. Messinger is analyzing photosynthetic and artificial water-splitting employing O 2 measurements, mass spectrometry (MIMS), EPR and XAS.

Photoautotrophic hydrogen production by eukaryotic microalgae under aerobic conditions

“…Potential H 2 ase reactivation was also observed after the exposure to 25% headspace oxygen for 48 h. Photosynthetic organisms were previously reported to display a slow rate of H 2 production owing to the oxygen sensitivity of H 2 ase 20,21 . Thus, the sensitivity of H 2 ase to oxygen has been implicated as a major obstacle to improving phototrophic biological hydrogen production 22 . However, Chader et al 23 showed that Chlorella sp.…”

An Institutional Approach to Solar Fuels Research

“…Prominent examples are the only biological catalyst for solar water-splitting, photosystem II, and hydrogenases that reduce protons to molecular hydrogen. [9] A combination of both enzymes leads in principle to a direct solar-to-H 2 conversion via photolytic water-splitting, resulting in molecular oxygen (O 2 ) as by-product. In practice however, this has proven very difficult for many reasons, including enzyme instability and O 2 -sensitivity of many hydrogenases.…”

“…One of the more successful areas is solar energy related research. This research covers projects involving the synthesis and application of nanomaterials such as carbon nanotubes [16][17][18] ; the production of organic optoelectronic devices [19][20][21] ; synthesis of industrial catalysts [22][23][24] ; fundamental studies on the mechanism of enzymes (such as photosystem II) [9,11,[25][26][27] ; elucidation of the genome sequence, metabolism and biomass formation of various species [28][29][30] ; combustion, gasification and torrefaction of biomass including ash behaviour [31][32][33][34][35][36][37] ; the improvement of biomass (wood) quantity and quality by breeding and genetic modification [38,39] ; and implementation of a biorefinery concept at industrial scale. [40][41][42][43][44][45] For building and maintaining these research facilities and efforts, internal and external funding is required.…”

“…2) connects 15 group leaders that cover the fields of plant physiology and natural photosynthesis (including photosynthetic water-splitting), catalysis, photochemistry, spectroscopy, crystallography, nanomaterials, physics, mathematics, and device-building. The approach is two-fold: (a) understanding and improving natural photosynthesis, [9,11,[25][26][27] and (b) applying this knowledge to the construction of low cost, printable artificial membranes for the direct (wireless) conversion of solar energy into fuels. [12,66] This environment is led by the author.…”

“…In practice however, this has proven very difficult for many reasons, including enzyme instability and O 2 -sensitivity of many hydrogenases. [9] Man-made Devices for Solar Energy Conversion (Artificial Photosynthesis)…”