scholarly journals Efficient water oxidation catalyzed by homogeneous cationic cobalt porphyrins with critical roles for the buffer base

2013 ◽  
Vol 110 (39) ◽  
pp. 15579-15584 ◽  
Author(s):  
D. Wang ◽  
J. T. Groves
Keyword(s):  
Water Oxidation ◽  
Cobalt Porphyrins ◽  
Buffer Base

scholarly journals Base-enhanced catalytic water oxidation by a carboxylate–bipyridine Ru(II) complex

2015 ◽  
Vol 112 (16) ◽  
pp. 4935-4940 ◽  
Author(s):  
Na Song ◽  
Javier J. Concepcion ◽  
Robert A. Binstead ◽  
Jennifer A. Rudd ◽  
Aaron K. Vannucci ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Proton Transfer ◽  
Water Oxidation ◽  
Proton Acceptor ◽  
Half Time ◽  
X Ray ◽  
X Ray Crystallography ◽  
Buffer Base ◽  
Electron Proton Transfer ◽  
C Nmr

In aqueous solution above pH 2.4 with 4% (vol/vol) CH3CN, the complex [RuII(bda)(isoq)2] (bda is 2,2′-bipyridine-6,6′-dicarboxylate; isoq is isoquinoline) exists as the open-arm chelate, [RuII(CO2-bpy-CO2−)(isoq)2(NCCH3)], as shown by 1H and 13C-NMR, X-ray crystallography, and pH titrations. Rates of water oxidation with the open-arm chelate are remarkably enhanced by added proton acceptor bases, as measured by cyclic voltammetry (CV). In 1.0 M PO43–, the calculated half-time for water oxidation is ∼7 μs. The key to the rate accelerations with added bases is direct involvement of the buffer base in either atom–proton transfer (APT) or concerted electron–proton transfer (EPT) pathways.

Cobalt porphyrins as homogeneous catalysts for water oxidation

2013 ◽  
Vol 49 (56) ◽  
pp. 6325 ◽  
Author(s):  
Takashi Nakazono ◽  
Alexander Rene Parent ◽  
Ken Sakai
Keyword(s):  
Water Oxidation ◽  
Homogeneous Catalysts ◽  
Cobalt Porphyrins

Thermal and photoinduced electron-transfer catalysis of high-valent metal-oxo porphyrins in oxidation of substrates

2016 ◽  
Vol 20 (01n04) ◽  
pp. 35-44 ◽  
Author(s):  
Shunichi Fukuzumi ◽  
Wonwoo Nam
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Water Oxidation ◽  
Photoinduced Electron Transfer ◽  
Hydrogen Abstraction ◽  
Eosin Y ◽  
Cobalt Porphyrins ◽  
Heme Domain ◽  
Visible Light Driven ◽  
High Valent

In this manuscript, we have overviewed thermal and photoinduced electron transfer catalysis of high-valent metal-oxo porphyrins in oxidation of various substrates. The high-valent iron-oxo porphyrin in cytochrome P450 (P450) is produced by photoinduced electron transfer from electron donors, such as triethanolamine (TEOA), to the excited state of a photosensitizer such as eosin Y, followed by the reduction of the heme domain of P450 by the resulting radical anion of the photosensitizer and the subsequent reaction of the reduced heme with dioxygen (O[Formula: see text]. Various substrates were oxidized by O2 in this visible light-driven electron-transfer catalytic reaction with several P450s from bacteria and humans. A manganese(V)-oxo corrorazine was produced by photoinduced electron transfer from the excited state of manganese(III) corrorazine to O2, followed by hydrogen abstraction from toluene derivatives, catalyzing the oxidation of toluene derivatives with O2 in the presence of an acid via photoinduced electron transfer catalysis. High-valent manganese-oxo porphyrins are also produced by photoinduced electron transfer from the excited state of [Ru(bpy)3][Formula: see text] (bpy = 2,2′-bipyridine) to electron acceptors, followed by electron transfer oxidation of manganese(III) porphyrins with [Ru(bpy)3][Formula: see text], catalyzing oxidation of various substrates with O2. Finally photoinduced electron-transfer catalysis of cobalt porphyrins is discussed for the photocatalytic water oxidation with persulfate.

Electrochemical and photoelectrochemical water splitting with a CoOx catalyst prepared by flame assisted deposition

2020 ◽  
Vol 49 (3) ◽  
pp. 588-592 ◽  
Author(s):  
Fusheng Li ◽  
Ziqi Zhao ◽  
Hao Yang ◽  
Dinghua Zhou ◽  
Yilong Zhao ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Water Splitting ◽  
Water Oxidation ◽  
Oxide Catalyst ◽  
Photoelectrochemical Water Splitting ◽  
Deposition Method ◽  
Photoelectrochemical Water Oxidation

A cobalt oxide catalyst prepared by a flame-assisted deposition method on the surface of FTO and hematite for electrochemical and photoelectrochemical water oxidation, respectively.

Impact Of Synthesis Route on the Water Oxidation Kinetics of Hematite Photoanodes

2020 ◽  
Author(s):  
Camilo A. Mesa ◽  
Ludmilla Steier ◽  
Benjamin Moss ◽  
Laia Francàs ◽  
James E. Thorne ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Reaction Kinetics ◽  
Water Oxidation ◽  
Oxidation Kinetics ◽  
Oxidation Reaction ◽  
Charge Accumulation ◽  
Optical Signals ◽  
Current Voltage ◽  
Voltage Performance ◽  
Kinetics Of

<p><i>Operando</i> spectroelectrochemical analysis is used to determine the water oxidation reaction kinetics for hematite photoanodes prepared using four different synthetic procedures. Whilst these photoanodes exhibit very different current / voltage performance, their underlying water oxidation kinetics are found to be almost invariant. Lower photoanode performance was found to correlate with the observation of optical signals indicative of charge accumulation in mid-gap oxygen vacancy states, indicating these states do not contribute directly to water oxidation.</p>

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