scholarly journals Enhanced Kinetics of Hole Transfer and Electrocatalysis during Photocatalytic Oxygen Evolution by Cocatalyst Tuning

ACS Catalysis ◽  
2016 ◽  
Vol 6 (7) ◽  
pp. 4117-4126 ◽  
Author(s):  
Ela Nurlaela ◽  
Hai Wang ◽  
Tatsuya Shinagawa ◽  
Sean Flanagan ◽  
Samy Ould-Chikh ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Hole Transfer ◽  
Kinetics Of

scholarly journals Photosystem II: Thermodynamics and Kinetics of Electron Transport from QA- to QB(QB- ) and Deleterious Effects of Copper(II)

1993 ◽  
Vol 48 (3-4) ◽  
pp. 234-240 ◽  
Author(s):  
G. Renger ◽  
H. M. Gleiter ◽  
E. Haag ◽  
F. Reifarth
Keyword(s):  
Oxygen Evolution ◽  
Manganese Content ◽  
Fluorescence Emission ◽  
Laser Flash ◽  
Fluorescence Induction ◽  
Oxygen Evolving Complex ◽  
Ps Ii ◽  
Thermodynamics And Kinetics ◽  
Redox Active ◽  
Kinetics Of

Studies on thermodynamics and kinetics of electron transfer from QA- to QB(QB-) were performed by monitoring laser flash induced changes of the relative fluorescence emission as a function of temperature (220 K < T < 310 K) in isolated thylakoids and PS II membrane fragments.In addition, effects of bivalent metal ions on PS II were investigated by measuring conventional fluorescence induction curves, oxygen evolution, manganese content and atrazine binding mostly in PS II membrane fragments. It was found: a) the normalized level of the fluorescence remaining 10 s after the actinic flash (Ft/F0) steeply increases at temperatures below -10 to - 20 °C, b) the fast phase of the transient fluorescence change becomes markedly retarded with decreasing temperatures, c) among different cations (Cu2+, Zn2+, Cd2+, Ni2+, Co2+) only Cu2+ exhibits marked effects in the concentration range below 100 μᴍ and d) Cu2+ decreases the normalized variable fluorescence, inhibits oxygen evolution and diminishes the affinity to atrazine binding without affecting the number of binding sites. The content of about four manganeses per functionally competent oxygen evolving complex is not changed by [Cu2+] < 70 μᴍ.Based on these findings it is concluded: i) a temperature dependent equilibrium between an inactive (I) and active (A) state of QA- reoxidation by QB(QB- ) is characterized by standard enthalpies ΔH° of 95 kJ mol-1 and 60 kJ mol-1 and standard entropies ΔS° of 370 kJ K-1 mol-1 and 240 kJ K-1 mol-1 in isolated thylakoids and PS II membrane fragments, respectively, ii) the activation energies of QA- reoxidation by plastoquinone bound to the QB site are about 30 kJ mol-1 (thylakoids) and 40 kJ mol-1 (PS II membrane fragments) in 220 K < T < 300 K, and iii) Cu2+ causes at least a two-fold effect on PS II by modifying the atrazine binding affinity at lower concentrations ( ~ 5 μᴍ) and interference with the redox active tyrosine Yz at slightly higher concentration ( ~ 10 μᴍ) leading to blockage of oxygen evolution.

Coupling NiCo catalysts with carbon quantum dots on hematite photoanodes for highly efficient oxygen evolution

2022 ◽  
Author(s):  
Yingpu Bi ◽  
Bin zhao ◽  
Chenchen Feng ◽  
Xiaojuan Huang ◽  
Yong Ding
Keyword(s):  
Quantum Dots ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
Carbon Quantum Dots ◽  
Hole Transfer ◽  
Highly Efficient ◽  
Pec Water Splitting

Highly efficient hole transfer from photoanodes to oxygen evolution catalysts is crucial for solar photoelectrochemical (PEC) water splitting. Herein, we demonstrated the coupling of NiCo catalysts with carbon quantum dots...

Zinc-telluride nanospheres as an efficient water oxidation electrocatalyst displaying a low overpotential for oxygen evolution

2019 ◽  
Vol 7 (46) ◽  
pp. 26410-26420 ◽  
Author(s):  
Maira Sadaqat ◽  
Laraib Nisar ◽  
Noor-Ul-Ain Babar ◽  
Fayyaz Hussain ◽  
Muhammad Naeem Ashiq ◽  
...  
Keyword(s):  
Water Splitting ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Water Oxidation ◽  
Zinc Telluride ◽  
Low Overpotential ◽  
Electrochemical Water Splitting ◽  
Kinetics Of

Electrochemical water splitting is economically unviable due to the sluggish kinetics of the anodically uphill oxygen evolution reaction (OER).

Study on kinetics of oxygen evolution on lead alloy anodes

1997 ◽  
Vol 4 (1) ◽  
pp. 69-72 ◽  
Author(s):  
Wenmi Chen ◽  
Bingkun Guo ◽  
Klaus Hein
Keyword(s):  
Oxygen Evolution ◽  
Lead Alloy ◽  
Kinetics Of
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