Introduction to Oxygen Evolving

The critical bottleneck for water splitting, which is important for sustainable production of hydrogen, has remained in sluggish oxygen evolving reaction (OER) requiring insufficiently low overpote.

Dissolved oxygen evolving from aviation fuel leads to an increase in the oxygen concentration in an inert aircraft fuel tank ullage that may increase the flammability of the tank.

Complexome profiling revealed that in the mutant CP43 was reduced to ∼23%, D1, D2, and CP47 to ∼30% of wild-type levels, while small PSII core subunits and components of the oxygen evolving complex were reduced at most by factor two.

Based on our present knowledge of the oxygen evolving complex a possible reaction mechanism is proposed for the interaction between NO and the S3 state.

The detrimental effects of salinity on the oxygen evolving-complex, the trapping of light energy in PSII, and delivering in the electron transport chain occurred earlier and more in the landrace than the cultivar.

Other identified proteins showing variations were ATPase beta subunit, UDP-glucose anthocyanin 5-O-glucosyltransferase, RNA-binding protein, putative transkelotase 1, putative ferredoxin-NAPD(H) oxide-reductase, and putative 33kDa oxygen evolving protein photosystem II.

The alterations in oxygen evolving capacity were evaluated by registration of flash-induced oxygen yields and kinetics of initial oxygen burst.

The Photosystem II (PSII) water oxidation to molecular oxygen process is catalyzed by an oxygen-bridged Mn4CaO5 cluster, known as Oxygen Evolving Complex (OEC) of PSII.

occurs at the Mn4CaO5 active site of the oxygen evolving complex (OEC) of photosystem II, there has been growing interest in synthetic multinuclear catalysts for promoting intramol.

Water is oxidized to dioxygen at the Oxygen Evolving Complex (OEC), a Mn4CaO5 inorganic core embedded on the lumen side of PSII.

PC3 with photocurrent density = 8 µA cm-2), which is encouraging for coupling with an oxygen evolving photoanode in tandem water splitting devices.

Edge-functionalised graphene (EFG) is included to mimic the metal-binding local protein environment, and the tyrosine residue, in the oxygen evolving complex (OEC) of PSII, while MnOx and Ca2+ are incorporated to mimic the Mn4CaO5 cluster.

Further, oxygen evolving enhancer protein and elongation factor Tu could be observed in the 2-DE gels of Phe and Phe-B methods, but could only be detected in the results of the Phe-B methods, showing that Phe-B method might be the optimized choice for proteomic analysis.

A novel underlying mechanism was observed that the limited construction of the trans-thylakoid proton gradient (ΔpH) caused by photoinactivation of the oxygen evolving complex (OEC) did not induce protonation of PsbS, thus explaining the inability to form quenching sites for qE induction.

Double normalised differential kinetics indicated adverse effects at the antennae, oxygen evolving complex and intersystem electron acceptors in cv.

The prepared 3D CoO@NiFe LDH/NF emerges a superior catalytic activity for oxygen evolving reaction (OER) in alkaline media, which only demands an overpotential of 225 mV at 20 mA cm-2.

Chlorophyll a fluorescence measurements (Fo, Fm, Fv, Fo/Fm, Fv/Fo, Fv/Fm and other JIP-test parameters) revealed that chromium stress caused PSII photoinhibition by damaging donor end of PSII (oxygen evolving complex) and acceptor end of PSII (over reduction of QA).

In natural photosynthesis, water oxidation occurs in the oxygen evolving complex (OEC), a manganese-oxo cluster {Mn4CaO5} with a cubane-like topology that is embedded within a redox-active protein environment located in photosystem II (PS II).

Water is oxidized to dioxygen at the Oxygen Evolving Complex (OEC), a Mn4CaO5 inorganic core embedded in the lumenal side of PSII.

Cyanobacteria are oxygen evolving, nitrogen fixing prokaryotes occur in every conceivable habitats but abundantly in water logged rice fields in several rice growing countries.

The prepared NiFe LDH-Ci/CC emerges a superior catalytic activity for oxygen evolving reaction in alkaline media, which only demands an overpotential of 240 mV at 20 mA cm−2 with a high stability for at least 90 h, and shows an excellent turnover frequency value of 0.

2O3−δ (BSCF), an oxygen evolving perovskite that exhibits excellent activity [1], has revealed a spinel surface structure that accommodates the conversion to the active oxyhydroxide phase during cyclic voltammetry (CV) [2].

5[Ge3PCo9(OH)5(H2O)4W30O115] ⋅ 45H2O (Co9), Na6K16[Ge4P4Co20(OH)14(H2O)18W36O150] ⋅ 61H2O (Co20) with non‐, quasi‐, or full cubane motifs structurally strongly reminiscent of the naturally occurring {Mn4Ca} oxygen evolving complex (OEC) in photosystem II was achieved.

Under high applied potential conditions, the oxygen evolving catalytic activity is reduced by 95 % in the absence of the PDA layer.

The catalytic site of PSII is a Mn4Ca cluster and is known as the oxygen evolving complex (OEC) of PSII.

5 x AA, such as increased dark respiration, reduced leaf pigment content, reduced maximum quantum yield of PSII, inactivation of the oxygen evolving complex of PSII and reduced performance index PITOT.

The Sr2+ substituted PSII is active but slower than with the native Ca2+ as an oxygen evolving catalyst.

Meanwhile, photosynthetic efficiency was significantly increased under low concentration of sodium acetate, however, when adding the high concentrations of sodium acetate, the oxygen evolving complex in donor side of reaction center was damaged, and electron transport at the donor and receptor sides of the reaction center was also suppressed, accompanied by the changes of the absorption, transfer, and application of light energy.

Furthermore, a hole transport pathway was further constructed by site-selective incorporation of an oxygen evolving catalyst (Co-Pi) in the ternary system via a photo-assisted electrodeposition or electrodeposition approach, which contributes to more enhanced separation efficiency and prolonged lifetime of photo-induced charge carriers together with improved photostability.

Resembling the cuboidal [CaMn3O4] subsite of the biological oxygen evolving complex (OEC), [Mn4O4] and [YMn3O4] complexes featuring ligands of different basicity and chelating properties were characterized by cyclic voltammetry.

The proposed mechanism shows parallels with the function of the oxygen evolving complex of photosystem II, and provides new insights into the mechanism of heterogeneous water oxidation on a metal oxide surface.

First we introduce tetranuclear Co(II)-based water oxidation catalysts featuring a cubane core as found in the oxygen evolving complex of nature's photosystem II.

Domain-based local pair natural orbital (DLPNO) coupled cluster single and double (CCSD) with triple perturbation (T) correction methods were applied for six different S1 structures of oxygen evolving complex (OEC) of photosystem II (PSII), showing that right-opened three S1 structures were nearly degenerated in energy.

High oxygen-vacancy ratio has been recognized as an important criterion for oxygen evolving electrocatalysts to achieve high catalytic performance.

The oxidation of water to O2 is catalyzed by the Oxygen Evolving Complex (OEC), a Mn4CaO5 complex in Photosystem II (PSII).

Oxygen evolving complex activity (Fv/Fo) and PSII maximum quantum efficiency (Fv/Fm) in R-grown plants were lower than plants grown under other light spectra.

To create the Artificial Leaf, an oxygen evolving complex of Photosystem II was mimicked, the most important property of which was the self-healing nature of the catalyst.

Using chlorophyll (Chl) a fluorescence transient (OJIP) measurements, we indicated that the photosynthetic apparatus of Aloe vera was damaged at chilling, as evaluated from decrease in maximal efficiency of PSII photochemistry (Fv/Fm) and in performance index (PIABS) coupled with lower values of photosynthetic electron transport chain components including the electron transport flux (φEo) and the inferred oxygen evolving complex activity (Fv/Fo).

Although WO3 is considered an oxygen evolving photocatalyst with decent stability and proper bandgap, its lower photocatalytic efficiency is ascribed to high charge recombination.

When the cyanobacterial cultures were exposed to UV-C radiation of varying doses (6, 12 and 18 mJ/cm2), concentrations of various photo-absorbing pigments, RuBisCO and D1 protein of PSII; activities of oxygen evolving complex, nitrogenase and glutamine synthetase were significantly increased upon 6 and 12 mJ/cm2 UV-C radiation exposures.

Our results showed that upon receiving a high UV-B dose, a severe inactivation of oxygen evolving complex (OEC) activity at the PSII donor side and irreversible PSII photodamage caused primarily by limitation of the acceptor side occurred, which overloaded protective mechanisms and finally led to the death of the plants.

This synthesis supports an emergence of H2S-driven anoxygenic photosynthesis in Cyanobacteria prior to the evolution of oxygenic photosynthesis and underscores a role for the former metabolism in fueling fine-tuning of the oxygen evolving complex and mechanisms to repair oxidative damage.

Domain-based local pair natural orbital (DLPNO) coupled cluster single and double (CCSD) with triple perturbation (T) correction methods were applied for fourteen different S2 structures of the CaMn4O5 cluster in oxygen evolving complex (OEC) of photosystem II (PSII).

Furthermore, the current knowledge of the structure and functional role of the three most well characterized Mn-containing metalloenzymes in plants; the oxygen evolving complex of photosystem II, Mn superoxide dismutase, and oxalate oxidase is summarized.

Additionally, the real-time quantitative PCR analysis of oxygen evolving complex genes in photosystem II, such as PsbO, PsbP, PsbQ, and PsbR, showed a significant reduction of the relative expression of these genes at the late stage of TYLCCNV A + β infection and at the vegetative stage of βC1 transgenic N.

Ex situ and operando X-ray absorption spectroscopy (XAS) was used to study the local electronic and geometric structure under oxygen evolving conditions.

We have achieved hydrogen generation derived from WD with BPMTHEA-2CC using an oxygen evolving reaction active TH dimensionally stable anode by imposing a voltage with less than the theoretical 1.

The spin structure in the S2 state and the crystal structure of the manganese cluster of the oxygen evolving complex of plant photosystem II was combined by the quantitative evaluation of the magnetic anisotropy of the g = 4 signal.

According to the obtained results, the incubation of native PSII preparations with Tb3+ cations caused an irreversible inhibition (by ~75% for 2 mM of Tb3+) of the oxygen evolving function.

Calcium ion plays an indispensable role for water oxidation by oxygen evolving complex (OEC) composed of a manganese-oxo cluster (Mn4CaO5) in Photosystem II.

The obtained results indicate that the observed increase in the efficiency of CO2 carboxylation after short-term UV-A:red radiation has resulted from the efficient linear electron transport due to maintaining the effective oxygen evolving complex (OEC) and increased total electron carriers.

Salt stress increased Vj, VI, ABS/RC, TRo/RC and DIo/RC but it decreased ETo/RC which indicated that salt stress damaged the donor end of PSII (oxygen evolving complex) and reaction centers.

According to density functional theory (DFT) computations, this structure may allow a reaction path involving iron as the oxygen evolving center and a nearby terrace O site on the γ-NiOOH support oxide as a hydrogen acceptor.

Photosystem II (PSII) uses water as the terminal electron donor, producing oxygen in the Mn4CaO5 oxygen evolving complex (OEC), while cytochrome c oxidase (CcO) reduces O2 to water in its heme–Cu binuclear center (BNC).

We applied our analysis, based on a linear response function of density and spin density, to two typical transition metal complex systems-the reaction centers of P450, and oxygen evolving center in Photosystem II, both of which contain open-shell transition metal ions.

K step was observed in heat stress and heat +Water stress stress which may be because of damage to Oxygen Evolving Complex indicating that low thermostability of the complex.

In this work, electro-precipitation of different TOCN gels has been performed on oxygen evolving anodes.

Understanding the role of Ca2+ ion in the oxygen evolving complex (OEC) of photosystem II (PSII) is essential in order to design commercially viable and efficient water oxidation catalysts.

The Mn Mn and Ca Mn distances obtained by the QM/MM calculations were found to be totally comparable to the SFX experiments, elucidating the entire Kok cycle involving the S4 transition state during the O O bond formation for water oxidation in the oxygen evolving complex (OEC) of photosystem II (PSII).

The conductivities of thin film cobalt oxygen evolving catalysts (Co-OECs) are examined for four variants differing in phosphate and borate anion compositions and pH.

Although the mechanism responsible for the decrease is not clear, relatively severe reductions in levels of Fv/Fo (an indicator of water-splitting activity) by TBT treatment than diuron treatment suggest that TBT inhibits photosynthetic function via inhibition of photosynthetic oxygen evolving systems, a different mechanism than that of diuron.

The optimized geometries of the CaMn4 OX (X = 5, 6) cluster in the oxygen evolving complex (OEC) of photosystem II (PSII) by large-scale quantum mechanics (QM) and molecular mechanics (MM) calculations are compared with recent serial femtosecond crystallography (SFX) results for the Si (i = 0-3) states.

This thesis describes a series of studies devoted toward the synthesis of model complexes that mimic aspects of structure, redox state, and spectroscopy of the oxygen evolving complex (OEC) of Photosystem II.

The resulting multi-functional coating yields BiVO_4 photoanodes with almost 100% efficient surface collection of holes under oxygen evolving reaction conditions.

Today's best molecular water oxidation catalysts reach turnover frequencies that are orders of magnitude higher than that of the natural oxygen evolving center in photosystem II.

One of the major challenges in developing sustainable energy storage systems is to discover robust oxygen evolving catalysts (OECs) that can efficiently oxidize water and produce oxygen, electrons and protons under highly oxidizing conditions.