Probing Porous Structure of Single Manganese Oxide Mesorods with Ionic Current

2013 ◽  
Vol 117 (47) ◽  
pp. 24836-24842 ◽  
Author(s):  
Trevor Gamble ◽  
Eleanor Gillette ◽  
Sang Bok Lee ◽  
Zuzanna S. Siwy
Keyword(s):  
Porous Structure ◽  
Manganese Oxide ◽  
Ionic Current

scholarly journals Morphological Features and Sorption Performance of Materials Based on Birnessite Exposed to Various Reductive Conditions

2018 ◽  
Vol 2 (4) ◽  
pp. 70
Author(s):  
Arseniy Portnyagin ◽  
Andrey Egorin ◽  
Alexey Golikov ◽  
Eduard Tokar ◽  
Vitaliy Mayorov ◽  
...  
Keyword(s):  
Porous Structure ◽  
Kinetic Analysis ◽  
Manganese Oxide ◽  
Structural Changes ◽  
Xrd Analysis ◽  
Operating Regime ◽  
Repeated Use ◽  
Temperature Programmed ◽  
Amorphous Surface ◽  
Sorption Characteristics

The article is devoted to the evolution of structural, morphological, and sorption characteristics of layered manganese oxide (birnessite) under various conditions close to the real operating regime of the sorbents for radioactive waste processing. To identify the phase composition in the birnessites, we implemented XRD analysis, while SEM and temperature-programmed reduction (TPR) were used to study morphological and redox features of the materials, respectively. Structural changes after various kinds of treatment of birnessites were tracked using low temperature nitrogen sorption. Sorption characteristics were assessed under static and in dynamic conditions on the efficiency of Sr2+ removal from simulated seawater. TPR combined with kinetic analysis revealed the decrease of particle sizes in the birnessites after repeated use in sorption-regeneration cycle and reduction with hydrazine. Despite the fact that the porous structure of the materials remains preserved, the surface morphology of birnessite changes drastically depending on the reducing agent. Hydrazine treatment increases the sorption performance of the birnessite followed by degradation of mechanical properties, thus, preventing such sorbent from repeated use. Kinetic analysis of TPR allows quantifying differences in morphology and porous structure of manganese oxide materials. The specific surface area, amorphous surface structure, and accessibility of Mn+3 sites are the most important factors for birnessite sorption performance.

scholarly journals Accumulation charge mechanisms in electrochemical systems formed based on activated carbon and manganese oxide

2020 ◽  
Vol 21 (1) ◽  
pp. 27-34
Author(s):  
B. K. Ostafiychuk ◽  
M. I. Kolkovskyi ◽  
B. I. Rachiy ◽  
P. I. Kolkovskyi ◽  
N. Ya. Ivanichok ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Activated Carbon ◽  
Electrochemical Performance ◽  
Porous Structure ◽  
Manganese Oxide ◽  
Specific Capacitance ◽  
Crystalline Structure ◽  
Carbon Material ◽  
Asymmetric Supercapacitors ◽  
Electrochemical Systems

In this work, the porous structure of the carbon material and the crystalline structure of manganese oxide α - modification (α - MnO2) have been investigated. The electrochemical performance of symmetric and asymmetric supercapacitors (α - MnO2 / Activated carbon) was investigated by cyclic voltammetry and galvanostatic cycling methods. The processes occur mainly at the electrode – electrolyte interface have been analyzed. It was determined that at discharge currents of 0.5 - 5 mA, the specific capacitance value for the α - MnO2 / Activated carbon hybrid capacitor exceeds the value of the symmetric capacitor by 45 - 55 % under the same conditions.

Solar hydrogen from a manganese oxide based thermochemical cycle

1999 ◽  
Vol 09 (PR3) ◽  
pp. Pr3-331-Pr3-335 ◽  
Author(s):  
M. Sturzenegger ◽  
J. Ganz ◽  
P. Nüesch ◽  
Th. Schelling
Keyword(s):  
Manganese Oxide ◽  
Thermochemical Cycle ◽  
Solar Hydrogen
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