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931.
In recent years, heteroatom-incorporated specially structured metal-free carbon nanomaterials have drawn huge attention among researchers. In comparison to the undoped carbon nanomaterials, heteroatoms such as nitrogen-, sulphur-, boron-, phosphorous-, etc., incorporated nanomaterials have become well-accepted as potential electrocatalysts in water splitting, supercapacitors and dye-sensitized solar cells. This review puts special emphasis on the most popular synthetic strategies of heteroatom-doped and co-doped metal-free carbon nanomaterials, viz., chemical vapor deposition, pyrolysis, solvothermal process, etc., utilized in last two decades. These specially structured nanomaterials’ extensive applications as potential electrocatalysts are taken into consideration in this article. Their comparative enhancement of electrocatalytic performance with incorporation of heteroatoms has also been discussed. 相似文献
932.
NiWO3 Nanoparticles Grown on Graphitic Carbon Nitride (g‐C3N4) Supported Toray Carbon as an Efficient Bifunctional Electrocatalyst for Oxygen and Hydrogen Evolution Reactions
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M. Praveen Kumar Pramila Murugesan Sankar Vivek Subbiah Ravichandran 《Particle & Particle Systems Characterization》2017,34(10)
Catalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are at the heart of water oxidation reactions. Despite continuous efforts, the development of OER/HER electrocatalysts with high activity at low cost remains a big challenge. Herein, a composite material consisting of TC@WO3@g‐C3N4@Ni‐NiO complex matrix as a bifunctional electrocatalyst for the OER and HER is described. Though the catalyst has modest activity for HER, it exhibits high OER activity thereby making it a better nonprecious electrocatalyst for both OER and HER and is further improved by g‐C3N4. The catalytic activity arises from the synergetic effects between WO3, Ni‐NiO, and g‐C3N4. A Ni‐NiO alloy and WO3 nanoparticles decorated on the g‐C3N4 surface supported toray carbon (TC) matrix (TC@WO3@g‐C3N4@Ni‐NiO) by a facile route that show an excellent and durable bifunctional catalytic activity for OER and HER in the alkaline medium are developed. This carbon nitride with binary metal/metal‐oxide matrix supported with TC exhibit an overpotential of 0.385 and 0.535 V versus RHE at a current density of 10 mA cm?2 (Tafel slopes of 0.057 and 0.246 V dec?1 for OER and HER, respectively), in 0.1 m NaOH . The catalyst is tested in water electrolysis for 17 h. 相似文献
933.
934.
Hansa Devi Gitanjali Pagare Ekta Jain Sankar P. Sanyal 《The European Physical Journal B - Condensed Matter and Complex Systems》2016,89(2):48
Dr. Salah Daoud pointed out the mistakes in formulae used for Debye temperature, soundvelocities and suggested corrections. We duly acknowledge the corrections pointed out byDr. Salah Daoud and also appreciate his focused study of our paper. 相似文献
935.
Sankar Hajra 《中国物理 B》2014,(9):129
We point out an error in Eq.(19) in our original paper [Chin. Phys. B 23 040402(2014)] and present the correct equation. 相似文献
936.
Dr. Debangsu Sil Firoz Shah Tuglak Khan Prof. Dr. Sankar Prasad Rath 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(41):14585-14597
The synthesis, structure, and properties of bischloro, μ‐oxo, and a family of μ‐hydroxo complexes (with BF4?, SbF6?, and PF6? counteranions) of diethylpyrrole‐bridged diiron(III) bisporphyrins are reported. Spectroscopic characterization has revealed that the iron centers of the bischloro and μ‐oxo complexes are in the high‐spin state (S=5/2). However, the two iron centers in the diiron(III) μ‐hydroxo complexes are equivalent with high spin (S=5/2) in the solid state and an intermediate‐spin state (S=3/2) in solution. The molecules have been compared with previously known diiron(III) μ‐hydroxo complexes of ethane‐bridged bisporphyrin, in which two different spin states of iron were stabilized under the influence of counteranions. The dimanganese(III) analogues were also synthesized and spectroscopically characterized. A comparison of the X‐ray structural parameters between diethylpyrrole and ethane‐bridged μ‐hydroxo bisporphyrins suggest an increased separation, and hence, less interactions between the two heme units of the former. As a result, unlike the ethane‐bridged μ‐hydroxo complex, both iron centers become equivalent in the diethylpyrrole‐bridged complex and their spin state remains unresponsive to the change in counteranion. The iron(III) centers of the diethylpyrrole‐bridged diiron(III) μ‐oxo bisporphyrin undergo very strong antiferromagnetic interactions (J=?137.7 cm?1), although the coupling constant is reduced to only a weak value in the μ‐hydroxo complexes (J=?42.2, ?44.1, and ?42.4 cm?1 for the BF4, SbF6, and PF6 complexes, respectively). 相似文献
937.
Cover Picture: Selective Oxidation of Alkyl‐Substituted Polyaromatics Using Ruthenium‐Ion‐Catalyzed Oxidation (Chem. Eur. J. 11/2015)
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938.
Selective Oxidation of Alkyl‐Substituted Polyaromatics Using Ruthenium‐Ion‐Catalyzed Oxidation
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Ewa Nowicka Meenakshisundaram Sankar Robert L. Jenkins David W. Knight David J. Willock Graham J. Hutchings Manuel Francisco Stuart H. Taylor 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(11):4285-4293
Ruthenium‐ion‐catalyzed oxidation of a range of alkylated polyaromatics has been studied. 2‐Ethylnaphthalene was used as a model substrate, and oxidation can be performed in either a conventional biphasic or in a monophasic solvent system. In either case the reaction rates and product selectivity are identical. The reaction products indicate that the aromatic ring system is oxidized in preference to the alkyl chain. This analysis is possible due to the development of a quantitative NMR protocol to determine the relative amounts of aliphatic and aromatic protons. From a systematic set of substrates we show that as the length of the alkyl chain substituent on a polyaromatic increases, the proportion of products in which the chain remains attached to the aromatic system increases. Larger polyaromatic systems, based on pyrene and phenanthrene, show greater reactivity than those with fewer aromatic rings, and the alkyl chains are more stable to oxidation. 相似文献
939.
JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
940.
The oxidation of hypophosphite and phosphite by the Anderson‐type hexamolybdocobaltate(III), [H6CoIIIMo6O24]3?, anion was investigated at pH 2 and 1, respectively, in aqueous medium. The reaction is found to occur through an outer‐sphere mechanism with a prior weak complex formation between the reactants. Under the reaction conditions, the oxidant exists in the [H5CoIIIMo5O20]2?, [H6CoIIIMo6O24]3?, and [H4CoIII2Mo10O38]6?(dimer) forms, and [H5CoIIIMo5O20]2? is the active species. Inhibition of the reaction by the oxidant anion and added molybdate ion kinetically indicates existence of prior equilibria between various forms of the oxidant. Both hypophosphite and phosphite exists in their protonated forms. The reaction involves direct electron transfer from the phosphorus center to the anion‐generating free radicals in a rate‐determining step. The effect of ionic strength and change in the solvent polarity did not affect the rate of the reaction. A probable mechanism was proposed leading to a complicated rate law as a result of involvement of prior equilibria between various forms of the oxidant. The activation parameters were also determined and are in support of the proposed mechanism. 相似文献