Studies on MnO2—II. Relationship between physicochemical properties and electrochemical activity of some synthetic MnO2 of different crystallographic forms

Kanungo, S. B.; Parida, Kulamani; Sant, B. R.

doi:10.1016/0013-4686(81)85092-x

Cited by 40 publications

(18 citation statements)

References 20 publications

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“…8 Heat-treatment at 300°C in air for 1 h has the effect of lowering the water content and consequently increases the electronic conductivity of the TPA-MO films. These factors are believed to have contributed collectively to the substantial higher charge capacity of films calcined at 300°C.…”

Section: Nitrogen Absorption-desorption (Bet) Analysis-mentioning

confidence: 99%

Material and Electrochemical Characterization of Tetrapropylammonium Manganese Oxide Thin Films as Novel Electrode Materials for Electrochemical Capacitors

Chin

Pang

Anderson

2002

J. Electrochem. Soc.

142

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Stable colloidal tetrapropylammonium manganese oxide ͑TPA-MO͒ was formed by the reduction of tetrapropylammonium permanganate with 2-butanol at room temperature. Thin films of TPA-MO were prepared using the sol-gel process by dip-coating directly onto clean nickel foils followed by heat-treatment under controlled conditions. The microstructure evolution of TPA-MO films at various calcination temperatures was characterized using Brunauer-Emmett-Teller method, X-ray diffraction, and scanning electron microscopy. The performance of these films as supercapacitors was evaluated using cyclic voltammetry in various aqueous electrolytes. These thin films exhibited excellent capacitive behavior with a specific capacitance of 720 F/g. These films also showed good reversibility and cycling stability, losing little more than 20% of their charge capacity after 1500 cycles. 4,5 As compared to other transition metal oxides such as NiO 2 , CoO, RuO 2 , and V 2 O 5 , these materials have received much attention and interest due to the low cost of raw materials, low toxicity, and environmentally friendly character.Studies of Pang et al. 4,5 have shown that sol-gel-derived MnO 2 thin films are a promising electrode material for supercapacitors due to their high reversibility, good cycling stability, and their high specific capacitance of 700 F/g. However, in spite of their favorable characteristics, the potential use of such sol-gel-derived MnO 2 films for fabricating practical devices is limited by the very dilute concentration (10 Ϫ3 M) of the MnO 2 colloidal suspension employed in coatings. Stable nanoparticles of manganese oxides having higher concentrations are difficult to prepare because of the strong tendency of manganese oxides to precipitate or coagulate during synthesis. Any increase in the MnO 2 concentration invariably leads to the destabilization of the colloidal suspension. Considerable efforts have therefore been directed toward exploring alternative precursors and approaches in order to prepare stable colloidal suspensions with higher concentrations of manganese dioxide particles.Recently, stable colloidal manganese oxides with concentrations as high as 0.57 M have been successfully prepared by incorporating tetralkylammonium cations ͑alkyl ϭ ethyl, propyl, and butyl͒ to prevent agglomerization of the negatively charged manganese oxide particles.6 Materials derived from such colloidal manganese oxides are reported to have lamellar structure with tetraalkylammonium cations intercalated between the manganese oxide layers. The manganese oxides have an average oxidation state of 3.70-3.79. 6 The pore size distribution of materials derived from such organic cation template-based manganese oxides can be well controlled by the size of the particles that constitute the templates, which can be subsequently removed by heat-treatment.In this paper, we report on the microstructural characterization of sol-gel-derived tetraproplyammonium manganese oxide ͑TPA-MO͒ thin films on nickel substrates and the electrochemical charact...

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Section: Nitrogen Absorption-desorption (Bet) Analysis-mentioning

confidence: 99%

Material and Electrochemical Characterization of Tetrapropylammonium Manganese Oxide Thin Films as Novel Electrode Materials for Electrochemical Capacitors

Chin

Pang

Anderson

2002

J. Electrochem. Soc.

142

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“…Recently, much effort has been devoted to the synthesis of 1D nanostructured manganese oxides and their assembly in hierarchical superstructures. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] 1D nanostructured manganese oxides have been reported to show promise as electrodes for lithium secondary batteries and supercapacitors, as well as redox catalysts. [11][12][13][14][15][16][17][18][19][20][21] It is well known that cation substitution can provide an effective tool for tailoring the physicochemical properties of metal oxides, [22,23] which means that the functionalities of these nanomaterials can be optimized by careful control of the cation composition.…”

Section: Introductionmentioning

confidence: 99%

Non‐Hydrothermal Synthesis of 1D Nanostructured Manganese‐Based Oxides: Effect of Cation Substitution on the Electrochemical Performance of Nanowires

Park

Lee

Kim

et al. 2007

Adv Funct Materials

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The synthesis of cation‐substituted 1D manganese oxide nanowires is achieved via a non‐hydrothermal oxidation reaction using a solid‐state precursor and conventional glassware. By changing the reaction conditions and precursor composition, it is possible to control the crystal structure and chemical composition of the resulting 1D nanostructured materials. The nanowires are found to exhibit promising electrochemical properties as cathode materials in lithium secondary batteries; moreover, the electrochemical properties of the nanowires can be improved by the partial replacement of Mn with Cr3+ cations. The measurements strongly suggest that the cation composition of the nanostructured metal oxides is very important for optimizing their electrode performance. The non‐hydrothermal solution synthesis method presented here provides an effective composition‐tailored approach for the fabrication of large quantities of 1D manganese oxide nanowires.

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“…Geometric current density (normalized to disk area) of (A) LaMn0. 57 and electronic conductivity 58 . Not only do these properties affect the mass activity of the oxides, but also they correlate with the electronic structure at the surface and thereby give rise to different specific activities.…”

Section: Measuring and Quantifying Orr Kinetics: Specific And Mass Acmentioning

confidence: 99%

Recent Insights into Manganese Oxides in Catalyzing Oxygen Reduction Kinetics

et al. 2015

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The sluggish kinetics of the oxygen reduction reaction (ORR) limit the efficiency of numerous oxygen-based energy conversion devices such as fuel cells and metal-air batteries. Among earth abundant catalysts, manganese-based oxides have the highest activities approaching that of precious metals. In this Review, we summarize and analyze literature findings to highlight key parameters that influence the catalysis of the ORR on manganese-based oxides, including the number of electrons transferred, specific and mass activities. These insights can help develop design guides for highly active ORR catalysts, and shape future fundamental research to gain new knowledge regarding the molecular mechanism of ORR catalysis.2

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Studies on MnO2—II. Relationship between physicochemical properties and electrochemical activity of some synthetic MnO2 of different crystallographic forms

Cited by 40 publications

References 20 publications

Material and Electrochemical Characterization of Tetrapropylammonium Manganese Oxide Thin Films as Novel Electrode Materials for Electrochemical Capacitors

Material and Electrochemical Characterization of Tetrapropylammonium Manganese Oxide Thin Films as Novel Electrode Materials for Electrochemical Capacitors

Non‐Hydrothermal Synthesis of 1D Nanostructured Manganese‐Based Oxides: Effect of Cation Substitution on the Electrochemical Performance of Nanowires

Recent Insights into Manganese Oxides in Catalyzing Oxygen Reduction Kinetics

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