scholarly journals The Biomimetic Inspiration for Renewable Hydrogen Fuel Production from Water Oxidation within Artificial Photosynthesis

2012 ◽  
Vol 65 (6) ◽  
pp. 597 ◽  
Author(s):  
Ron J. Pace ◽  
Rob Stranger

The thermodynamic constraints for the operation of the water oxidizing Mn4/Ca cluster within Photosystem II (PS II) are discussed. These are then examined in the light of the known redox chemistry of hydrated Mn-oxo systems and relevant model compounds. It is shown that the latest high resolution crystal structure of cyanobacterial PS II suggests an organization of the mono Ca tetranuclear Mn cluster that naturally accommodates the stringent requirements for successive redox potential constancy, with increasing total oxidation state, which the enzyme function imposes. This involves one region of the Mn4/Ca cluster being dominantly involved with substrate water binding, while a separate, single Mn is principally responsible for the redox accumulation function. Recent high level computational chemical investigations by the authors’ strongly support this, with a computed pattern of Mn oxidation states throughout the catalytic cycle being completely consistent with this interpretation. Strategies to design synthetic, biomimetic constructs utilizing this approach for efficient electrolytic generation of hydrogen fuel within artificial photosynthesis are briefly discussed.

Author(s):  
Eitan Yohanan ◽  
Maytal Caspary Toroker

Electrolysis of water to produce green and renewable hydrogen fuel is of great interest in clean energy field. water molecules can be decomposed to hydrogen and oxygen through catalysis. catalytic...


Author(s):  
Seyed Ehsan Hosseini

Renewable and sustainable energy has an evolving story as the ongoing trade war in the word is influencing crude oil prices. Moreover, the global warming is an inevitable consequence of the worldwide increasing rate of fossil fuel utilization which has persuaded the governments to invest on the clean and sustainable energy resources. In recent years, the cost of green energy has tumbled, making the price of renewables competitive to the fossil fuels. Although, the hydrogen fuel is still extremely expensive compared to the crude oil price, investigations about clean hydrogen fuel production and utilization has been developed significantly which demonstrate the importance of the hydrogen fuel in the future. This article aims to scrutinize the importance of green hydrogen fuel production from solar/wind energy.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Amr Radwan ◽  
Huihui Jin ◽  
Daping He ◽  
Shichun Mu

AbstractThe core reactions for fuel cells, rechargeable metal–air batteries, and hydrogen fuel production are the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER), which are heavily dependent on the efficiency of electrocatalysts. Enormous attempts have previously been devoted in non-noble electrocatalysts born out of metal–organic frameworks (MOFs) for ORR, OER, and HER applications, due to the following advantageous reasons: (i) The significant porosity eases the electrolyte diffusion; (ii) the supreme catalyst–electrolyte contact area enhances the diffusion efficiency; and (iii) the electronic conductivity can be extensively increased owing to the unique construction block subunits for MOFs-derived electrocatalysis. Herein, the recent progress of MOFs-derived electrocatalysts including synthesis protocols, design engineering, DFT calculations roles, and energy applications is discussed and reviewed. It can be concluded that the elevated ORR, OER, and HER performances are attributed to an advantageously well-designed high-porosity structure, significant surface area, and plentiful active centers. Furthermore, the perspectives of MOF-derived electrocatalysts for the ORR, OER, and HER are presented.


2020 ◽  
Author(s):  
Rong Chen ◽  
Gui-Lin Zhuang ◽  
Zhi-Ye Wang ◽  
Yi-Jing Gao ◽  
Zhe Li ◽  
...  

Abstract Photosynthesis in nature uses the Mn4CaO5 cluster as the oxygen-evolving center to catalyze the water oxidation efficiently in photosystem II (PS II). Herein, we demonstrate a bio-inspired heterometallic cluster LnCo3 (Ln = Nd, Eu and Ce) clusters, which can be viewed as synthetic analogs of CaMn4O5 cluster. Anchoring LnCo3 on phosphorus-doped graphitic carbon nitrides (PCN) shows efficient overall water splitting without any sacrificial reagents. The NdCo3/PCN-c photocatalyst exhibits excellent water splitting activity and a quantum efficiency of 2.0% at 350 nm. Ultrafast transient absorption (TA) spectroscopy revealed the transfer of photoexcited electron and hole into the PCN and LnCo3 for hydrogen and oxygen evolution reactions, respectively. DFT calculation showed the cooperative water activation on lanthanide and O-O bond formation on transition metal for water oxidation. This work not only prepares a synthetic model of bio-inspired oxygen-evolving center but also provides an effective strategy to realize light-driven overall water splitting.


2020 ◽  
Vol 117 (23) ◽  
pp. 12624-12635 ◽  
Author(s):  
Mohamed Ibrahim ◽  
Thomas Fransson ◽  
Ruchira Chatterjee ◽  
Mun Hon Cheah ◽  
Rana Hussein ◽  
...  

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.


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