Unravelling the water oxidation mechanism on NaTaO3-based photocatalysts

2020 ◽  
Vol 8 (14) ◽  
pp. 6812-6821 ◽  
Author(s):  
Qian Ding ◽  
Yang Liu ◽  
Tao Chen ◽  
Xiaoyu Wang ◽  
Zhaochi Feng ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Oxidation Mechanism ◽  
Lattice Oxygen

A lattice-oxygen evolved, three-step two-site mechanism is proposed for photocatalytic water oxidation on NaTaO3-based photocatalysts.

Activating the lattice oxygen oxidation mechanism in amorphous molybdenum cobalt oxide nanosheets for water oxidation

2022 ◽  
Author(s):  
Xiang Wang ◽  
Congcong Xing ◽  
Zhifu Liang ◽  
Pablo Guardia ◽  
Xu Han ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Water Oxidation ◽  
Oxidation Mechanism ◽  
Water Electrolysis ◽  
Cost Effective ◽  
Lattice Oxygen ◽  
Energy Technologies ◽  
Co2 Electroreduction ◽  
Oxygen Oxidation ◽  
The Cost

The cost-effective deployment of several key energy technologies, such as water electrolysis, CO2 electroreduction and metal-air batteries, relies on the design and engineering of cost-effective catalysts able to accelerate the...

scholarly journals Correction: Activating the lattice oxygen in (Bi0.5Co0.5)2O3 by vacancy modulation for efficient electrochemical water oxidation

2021 ◽  
Vol 9 (8) ◽  
pp. 5111-5112
Author(s):  
Huan Liu ◽  
Xiaoning Li ◽  
Cailing Peng ◽  
Liuyang Zhu ◽  
Yuanxi Zhang ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Lattice Oxygen

Correction for ‘Activating the lattice oxygen in (Bi0.5Co0.5)2O3 by vacancy modulation for efficient electrochemical water oxidation’ by Huan Liu et al., J. Mater. Chem. A, 2020, 8, 13150–13159, DOI: 10.1039/D0TA03411H.

Lattice Oxygen Redox Chemistry in Solid-State Electrocatalysts for Water Oxidation

2021 ◽  
Author(s):  
Ning Zhang ◽  
Yang Chai
Keyword(s):  
Solid State ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Water Oxidation ◽  
Water Electrolysis ◽  
Redox Chemistry ◽  
Lattice Oxygen ◽  
Vital Importance ◽  
Production Of Hydrogen ◽  
Overall Efficiency

Fundamental understandings towards oxygen evolution reaction (OER) are of vital importance as it dominates the overall efficiency of water electrolysis – a compelling technique for sustainable production of hydrogen feedstock....

Activating the lattice oxygen in (Bi0.5Co0.5)2O3 by vacancy modulation for efficient electrochemical water oxidation

2020 ◽  
Vol 8 (26) ◽  
pp. 13150-13159
Author(s):  
Huan Liu ◽  
Xiaoning Li ◽  
Cailing Peng ◽  
Liuyang Zhu ◽  
Yuanxi Zhang ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Lattice Oxygen ◽  
And Performance

Lattice-oxygen-active (Bi0.5Co0.5)2O3 was successfully prepared through vacancy modulation and demonstrated great OER activity and performance.

scholarly journals Untangling the sequence of events during the S2→ S3transition in photosystem II and implications for the water oxidation mechanism

2020 ◽  
Vol 117 (23) ◽  
pp. 12624-12635 ◽  
Author(s):  
Mohamed Ibrahim ◽  
Thomas Fransson ◽  
Ruchira Chatterjee ◽  
Mun Hon Cheah ◽  
Rana Hussein ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Water Oxidation ◽  
Donor Site ◽  
Oxidation Mechanism ◽  
Oxygenic Photosynthesis ◽  
Acceptor Site ◽  
Oxygen Evolving Complex ◽  
Ps Ii ◽  
Sequence Of Events ◽  
Large Channel

In oxygenic photosynthesis, light-driven oxidation of water to molecular oxygen is carried out by the oxygen-evolving complex (OEC) in photosystem II (PS II). Recently, we reported the room-temperature structures of PS II in the four (semi)stable S-states, S1, S2, S3, and S0, showing that a water molecule is inserted during the S2→ S3transition, as a new bridging O(H)-ligand between Mn1 and Ca. To understand the sequence of events leading to the formation of this last stable intermediate state before O2formation, we recorded diffraction and Mn X-ray emission spectroscopy (XES) data at several time points during the S2→ S3transition. At the electron acceptor site, changes due to the two-electron redox chemistry at the quinones, QAand QB, are observed. At the donor site, tyrosine YZand His190 H-bonded to it move by 50 µs after the second flash, and Glu189 moves away from Ca. This is followed by Mn1 and Mn4 moving apart, and the insertion of OX(H) at the open coordination site of Mn1. This water, possibly a ligand of Ca, could be supplied via a “water wheel”-like arrangement of five waters next to the OEC that is connected by a large channel to the bulk solvent. XES spectra show that Mn oxidation (τ of ∼350 µs) during the S2→ S3transition mirrors the appearance of OXelectron density. This indicates that the oxidation state change and the insertion of water as a bridging atom between Mn1 and Ca are highly correlated.

scholarly journals Lattice oxygen activation enabled by high-valence metal sites for enhanced water oxidation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ning Zhang ◽  
Xiaobin Feng ◽  
Dewei Rao ◽  
Xi Deng ◽  
Lejuan Cai ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Oxygen Activation ◽  
Lattice Oxygen

scholarly journals Electron, proton and hydrogen–atom transfers in photosynthetic water oxidation

2002 ◽  
Vol 357 (1426) ◽  
pp. 1383-1394 ◽  
Author(s):  
Cecilia Tommos
Keyword(s):  
Photosystem Ii ◽  
Proton Transfer ◽  
Water Oxidation ◽  
Oxidation Mechanism ◽  
Bulk Solution ◽  
Hydrogen Atoms ◽  
Redox Active ◽  
Hydrogen Atom Transfers ◽  
Reduce Carbon Dioxide ◽  
Photosynthetic Water Oxidation

When photosynthetic organisms developed so that they could use water as an electron source to reduce carbon dioxide, the stage was set for efficient proliferation. Algae and plants spread globally and provided the foundation for our atmosphere and for O 2 –based chemistry in biological systems. Light–driven water oxidation is catalysed by photosystem II, the active site of which contains a redox–active tyrosine denoted Y Z , a tetramanganese cluster, calcium and chloride. In 1995, Gerald Babcock and co–workers presented the hypothesis that photosynthetic water oxidation occurs as a metallo–radical catalysed process. In this model, the oxidized tyrosine radical is generated by coupled proton/electron transfer and re–reduced by abstracting hydrogen atoms from substrate water or hydroxide–ligated to the manganese cluster. The proposed function of Y Z requires proton transfer from the tyrosine site upon oxidation. The oxidation mechanism of Y Z in an inhibited and O 2 –evolving photosystem II is discussed. Domino–deprotonation from Y Z to the bulk solution is shown to be consistent with a variety of data obtained on metal–depleted samples. Experimental data that suggest that the oxidation of Y Z in O 2 –evolving samples is coupled to proton transfer in a hydrogen–bonding network are described. Finally, a dielectric–dependent model for the proton release that is associated with the catalytic cycle of photosystem II is discussed.

scholarly journals Direct and indirect role of Fe doping in NiOOH monolayer for water oxidation catalysis

2021 ◽  
Author(s):  
Manish Kumar ◽  
Simone Piccinin ◽  
Varadharajan Srinivasan
Keyword(s):  
Water Oxidation ◽  
Active Sites ◽  
Oxidation Catalysis ◽  
Lattice Oxygen ◽  
Nucleophilic Attack ◽  
Different Types ◽  
Water Oxidation Catalysis ◽  
Experimental Findings ◽  
Precise Role

The oxygen evolution reaction (OER) activity of pristine NiOOH is enhanced by doping with Fe. However, the precise role of Fe is still being debated. Here, we use the first-principles DFT+U approach to study three different types of active sites: one on pristine and the other two on Fe-doped NiOOH monolayers to account for the direct and indirect roles of Fe. To compare the activity of the active sites, we consider two mechanisms of OER based on the source of O-O bond formation. Our results show that the mechanism involving the coupling of lattice oxygen is generally more favorable than water nucleophilic attack on lattice oxygen. On doping with Fe, the overpotential of NiOOH is reduced by 0.33 V in excellent agreement with experimental findings. Introducing Fe at active sites results in different potential determining steps (PDS) in the two mechanisms, whereas Ni sites in pristine and Fe-doped NiOOH have the same PDS regardless of the mechanism. The Fe sites not only have the lowest overpotential but also decrease the overpotential for Ni sites.

scholarly journals Iron-TAML Complexes: A Computational Approach to Improving Stability

2021 ◽  
Author(s):  
◽  
Kevin Tuano
Keyword(s):  
Water Oxidation ◽  
Density Functional ◽  
Prolonged Exposure ◽  
Computational Study ◽  
Macrocyclic Ligand ◽  
Oxidation Mechanism ◽  
Nucleophilic Attack ◽  
Functional Theory ◽  
The Stability ◽  
Oxidation Chemistry

<p>Researchers at the Institute for Green Oxidation Chemistry of the Carnegie Mellon University developed a group of catalysts called tetra amido macrocyclic ligand (TAML) activators. The purpose of that research was that TAML activators would breakdown pollutants in the presence of a sacrificial oxidant. Furthermore, the catalyst was designed to decompose on a required timescale, as to not damage the environment by prolonged exposure. Since the initial designs from the 1980’s, the TAML structure has undergone significant changes to increase efficiency or selectivity. Other uses of this group of catalysts have been explored, namely, the oxidation of water to molecular oxygen.  This work presents a computational study using Density Functional Theory (DFT) which addresses the issue regarding the stability of certain iron-TAML intermediates in the water oxidation mechanism. Hence, the work seeks to explore how changing certain groups on the TAML ring can affect the stability of the reactive intermediates and the activation energy of the nucleophilic attack within the mechanism. The work highlights the importance of the fluorinated tail of the TAML structure in the accessibility of the desired transition state.</p>

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