scholarly journals Carbon fibre paper coated by a layered manganese oxide: a nano-structured electrocatalyst for water-oxidation with high activity over a very wide pH range

2019 ◽  
Vol 7 (44) ◽  
pp. 25333-25346 ◽  
Author(s):  
Jens Melder ◽  
Stefan Mebs ◽  
Philipp A. Heizmann ◽  
Rebekka Lang ◽  
Holger Dau ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Manganese Oxide ◽  
High Activity ◽  
Water Oxidation ◽  
Wide Ph Range ◽  
Ph Range ◽  
Coated Carbon ◽  
Layered Manganese Oxide

Manganese oxide coated carbon fibre paper electrodes (MnOx/CFP) exhibit promising water oxidation activities and stabilities for applications in alkaline, neutral and even acidic electrolytes.

Surprisingly Low Reactivity of Layered Manganese Oxide toward Water Oxidation in Fe/Ni-Free Electrolyte under Alkaline Conditions

2022 ◽  
Author(s):  
Mahya Salmanion ◽  
Ivan Kondov ◽  
Matthias Vandichel ◽  
Pavlo Aleshkevych ◽  
Mohammad Mahdi Najafpour
Keyword(s):  
Manganese Oxide ◽  
Water Oxidation ◽  
Alkaline Conditions ◽  
Layered Manganese Oxide

scholarly journals Adsorption of As(V) by the Novel and Efficient Adsorbent Cerium-Manganese Modified Biochar

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2720
Author(s):  
Ting Liang ◽  
Lianfang Li ◽  
Changxiong Zhu ◽  
Xue Liu ◽  
Hongna Li ◽  
...  
Keyword(s):  
Manganese Oxide ◽  
Photoelectron Spectroscopy ◽  
Water Environment ◽  
Polluted Water ◽  
X Ray ◽  
Modified Biochar ◽  
Wide Ph Range ◽  
Infrared Spectrometer ◽  
Pseudo Second Order ◽  
Ph Range

Arsenic has become a global concern in water environment, and it is essential to develop efficient remediation methods. In this study, a novel adsorbent by loading cerium and manganese oxide onto wheat straw-modified biochar (MBC) was manufactured successfully aiming to remove arsenic from polluted water. Through scanning electron microscopy and energy-dispersive spectroscopy (SEM-EDS), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometer (FT-IR), and other techniques, it was found the loading of cerium and manganese oxide on MBC played a significant role in As(V) adsorption. The results of the batch test showed that the adsorption of MBC followed the pseudo-second order kinetics and Langmuir equation. The adsorption capacity of MBC was 108.88 mg As(V)/g at pH = 5.0 (C0 = 100 mg/L, dosage = 0.5 g/L, T = 298 K) with considerable improvement compared to the original biochar. Moreover, MBC exhibited excellent performance over a wide pH range (2.0~11.0). Thermodynamics of the sorption reaction showed that the entropy (ΔS), changes of enthalpy (ΔH) and Gibbs free energy (ΔG), respectively, were 85.88 J/(moL·K), 22.54 kJ/mol and −1.33 to −5.20 kJ/mol at T = 278~323 K. During the adsorption, the formation of multiple complexes under the influence of its abundant surface M-OH (M represents the Ce/Mn) groups involving multiple mechanisms that included electrostatic interaction forces, surface adsorption, redox reaction, and surface complexation. This study indicated that MBC is a promising adsorbent to remove As(V) from polluted water and has great potential in remediating of arsenic contaminated environment.

scholarly journals Rapid water oxidation electrocatalysis by a ruthenium complex of the tripodal ligand tris(2-pyridyl)phosphine oxide

2015 ◽  
Vol 6 (4) ◽  
pp. 2405-2410 ◽  
Author(s):  
Andrew G. Walden ◽  
Alexander J. M. Miller
Keyword(s):  
Phosphine Oxide ◽  
Water Oxidation ◽  
Ruthenium Complex ◽  
Tripodal Ligand ◽  
Wide Ph Range ◽  
Ph Range

A ruthenium complex of the tripodal ligand tris(2-pyridyl)phosphine oxide exhibits rapid water oxidation electrocatalysis over a wide pH range.

Gold nanorods or nanoparticles deposited on layered manganese oxide: new findings

2015 ◽  
Vol 39 (9) ◽  
pp. 7260-7267 ◽  
Author(s):  
Mohammad Mahdi Najafpour ◽  
Seyedeh Maedeh Hosseini ◽  
Małgorzata Hołyńska ◽  
Tatsuya Tomo ◽  
Suleyman I. Allakhverdiev
Keyword(s):  
Manganese Oxide ◽  
Gold Nanorods ◽  
Water Oxidation ◽  
Oxide Phase ◽  
Oxidation Activity ◽  
Mn Oxide ◽  
New Findings ◽  
Layered Manganese Oxide

Our results show that nano-sized gold has no significant effect on the water-oxidation activity of the Mn oxide phase in the presence of Ce(iv).

scholarly journals Electronic structure effects on catalytic water oxidation activity by layered manganese oxide phases

2020 ◽  
Author(s):  
Michael Zdilla ◽  
Daniel R Strongin ◽  
John P Perdew ◽  
Eric Borguet ◽  
Michael L Klein ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Manganese Oxide ◽  
Water Oxidation ◽  
Oxidation Activity ◽  
Oxide Phases ◽  
Layered Manganese Oxide

scholarly journals Systematic Doping of Cobalt into Layered Manganese Oxide Sheets Substantially Enhances Water Oxidation Catalysis

2018 ◽  
Vol 57 (2) ◽  
pp. 557-564 ◽  
Author(s):  
Ian G. McKendry ◽  
Akila C. Thenuwara ◽  
Samantha L. Shumlas ◽  
Haowei Peng ◽  
Yaroslav V. Aulin ◽  
...  
Keyword(s):  
Manganese Oxide ◽  
Water Oxidation ◽  
Oxidation Catalysis ◽  
Water Oxidation Catalysis ◽  
Layered Manganese Oxide

Oxidation of CrIII aminocarboxylate complexes by hydrous manganese oxide: products and time course behaviour

2015 ◽  
Vol 12 (1) ◽  
pp. 33 ◽  
Author(s):  
Richard F. Carbonaro ◽  
Alan T. Stone
Keyword(s):  
Manganese Oxide ◽  
Time Course ◽  
Ethylenediaminetetraacetic Acid ◽  
Environmental Concern ◽  
Iminodiacetic Acid ◽  
Nitrilotriacetic Acid ◽  
Product Distribution ◽  
Hydrous Manganese Oxide ◽  
Wide Ph Range ◽  
Ph Range

Environmental context Oxidation of CrIII (trivalent chromium) to CrVI (hexavalent chromium) is of environmental concern because CrVI is a known mutagen and carcinogen. Our results show that hydrous manganese oxide (HMO) is capable of oxidising soluble CrIII complexed with iminodiacetic acid and nitrilotriacetic acid to CrVI at appreciable rates. CrVI production from soluble CrIII organic complexes is therefore expected to occur in natural and engineered systems that contain HMO. Abstract MnIII,IV (hydr)oxides are believed to be the principal oxidants of CrIII in the subsurface. In nearly all previous work on this subject, the CrIII reactant was prepared from inorganic salts (e.g. nitrate, chloride, sulfate). In our present work, CrIII complexes with the synthetic chelating agents iminodiacetic acid (IDA) and nitrilotriacetic acid (NTA) were reacted with hydrous manganese oxide (HMO) over a wide pH range to examine rates of reaction and product distribution. Capillary electrophoresis was used to quantify changes in reactant (CrIII–IDA and CrIII–NTA) and product (CrVI, free IDA and free NTA) concentrations as a function of time. In addition, a small number of experiments were performed using solutions prepared from CrIII alum (KCr(SO4)2·12H2O(s)) as the CrIII reactant. CrIII–IDA and CrIII–NTA were oxidised to CrVI, but rates were considerably lower than those obtained using inorganic CrIII. Within the timescales of our experiments, complete conversion of CrIII–NTA occurred at pH >7, but not under moderately acidic conditions, even when there was a large stoichiometric excess of HMO. MnCl2 addition experiments indicated that the observed reaction inhibition was attributable to MnII generation during the reaction. Our previous work has shown that citric acid, IDA, NTA and ethylenediaminetetraacetic acid solubilise CrIII from amorphous Cr(OH)3(s) at appreciable rates. The results of this study show that HMO is capable of oxidising the resulting soluble CrIII complexes, providing a viable mechanism for CrIII oxidation to CrVI over a wide pH range.

Fragments of Layered Manganese Oxide Are the Real Water Oxidation Catalyst after Transformation of Molecular Precursor on Clay

2014 ◽  
Vol 136 (20) ◽  
pp. 7245-7248 ◽  
Author(s):  
M. M. Najafpour ◽  
Atefeh N. Moghaddam ◽  
Holger Dau ◽  
Ivelina Zaharieva
Keyword(s):  
Manganese Oxide ◽  
Water Oxidation ◽  
Oxidation Catalyst ◽  
The Real ◽  
Molecular Precursor ◽  
Layered Manganese Oxide
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