Influence of oxalic acid on the dissolution kinetics of manganese oxide

Godunov, E. B.; Artamonova, I. V.; Горичев, И. Г.; Lainer, Yu. A.

doi:10.1134/s0036029512110079

Cited by 8 publications

(4 citation statements)

References 2 publications

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“…The λ-MnO 2 host dielectrically screens the positive charge, stabilizing it in the structure. [46,47] The same LiMn 2 O 4 sample was transferred to different electrolyte solutions and CV curves were measured in each electrolyte. Our experimental measurements suggest that this bulk electronic charge-switching mechanism accounts for up to 20%-30% of the total capacity, conspicuously close to the 27% of residual Li left in LiMn 2 O 4 upon complete discharge [5,44] and the ≈20% of Mn centers which are thought to contribute to the rapid charge-storage in pseudocapacitive α-MnO 2 with incorporated Na + .…”

Section: Deconvolution Of Capacitive and Diffusive Charge Storagementioning

confidence: 99%

“…is precluded by instability of LiMn 2 O 4 at pH < 4. [46,47] The same LiMn 2 O 4 sample was transferred to different electrolyte solutions and CV curves were measured in each electrolyte. We observed small, but distinct differences between the cations; in Na + and K + electrolytes a third peak is observed within the same region where we measured two peaks in the Li + electrolyte, and no peaks are observed in this region in the Mg 2+ electrolyte.…”

Section: Deconvolution Of Capacitive and Diffusive Charge Storagementioning

confidence: 99%

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Band Diagram and Rate Analysis of Thin Film Spinel LiMn₂O₄ Formed by Electrochemical Conversion of ALD‐Grown MnO

Young

Schnabel

Holder

et al. 2016

Adv Funct Materials

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Nanoscale spinel lithium manganese oxide is of interest as a high-rate cathode material for advanced battery technologies among other electrochemical applications. In this work, the synthesis of ultrathin films of spinel lithium manganese oxide (LiMn 2 O 4 ) between 20 and 200 nm in thickness by room-temperature electrochemical conversion of MnO grown by atomic layer deposition (ALD) is demonstrated. The charge storage properties of LiMn 2 O 4 thin films in electrolytes containing Li + , Na + , K + , and Mg 2+ are investigated. A unified electrochemical band-diagram (UEB) analysis of LiMn 2 O 4 informed by screened hybrid density functional theory calculations is also employed to expand on existing understanding of the underpinnings of charge storage and stability in LiMn 2 O 4 . It is shown that the incorporation of Li + or other cations into the host manganese dioxide spinel structure (λ-MnO 2 ) stabilizes electronic states from the conduction band which align with the known redox potentials of LiMn 2 O 4 . Furthermore, the cyclic voltammetry experiments demonstrate that up to 30% of the capacity of LiMn 2 O 4 arises from bulk electronic charge-switching which does not require compensating cation mass transport. The hybrid ALD-electrochemical synthesis, UEB analysis, and unique charge storage mechanism described here provide a fundamental framework to guide the development of future nanoscale electrode materials for ion-incorporation charge storage.

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Section: Deconvolution Of Capacitive and Diffusive Charge Storagementioning

confidence: 99%

Section: Deconvolution Of Capacitive and Diffusive Charge Storagementioning

confidence: 99%

Band Diagram and Rate Analysis of Thin Film Spinel LiMn₂O₄ Formed by Electrochemical Conversion of ALD‐Grown MnO

Young

Schnabel

Holder

et al. 2016

Adv Funct Materials

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“…Thus, the concentration of free manganese in the medium increased more than five times compared to selenium-free treatment (Figure 2a). Since the fungi are capable of dissolving manganese oxides via both reductive and oxidative pathways via extracellular metabolites [50,51], it is very likely that the presence of selenium prompted extrusion of redoxactive metabolites or enzymes responsible for hausmannite dissolution, e.g., exposure of fungus Beauveria caledonica to heavy metals led to overexcretion of citric and oxalic acids, with the former reported to actively contribute to the reductive dissolution of manganese oxides in acidic solutions [52].…”

Section: Discussionmentioning

confidence: 99%

Fungal Mobilization of Selenium in the Presence of Hausmannite and Ferric Oxyhydroxides

Farkas

Vojtková

Bujdoš

et al. 2021

JoF

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Bioleaching of mineral phases plays a crucial role in the mobility and availability of various elements, including selenium. Therefore, the leachability of selenium associated with the surfaces of ferric and manganese oxides and oxyhydroxides, the prevailing components of natural geochemical barriers, has been studied in the presence of filamentous fungus. Both geoactive phases were exposed to selenate and subsequently to growing fungus Aspergillus niger for three weeks. This common soil fungus has shown exceptional ability to alter the distribution and mobility of selenium in the presence of both solid phases. The fungus initiated the extensive bioextraction of selenium from the surfaces of amorphous ferric oxyhydroxides, while the hausmannite (Mn3O4) was highly susceptible to biodeterioration in the presence of selenium. This resulted in specific outcomes regarding the selenium, iron, and manganese uptake by fungus and residual selenium concentrations in mineral phases as well. The adverse effects of bioleaching on fungal growth are also discussed.

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“…The proposed dissolution mechanism occurs through the adsorption of oxalate ion onto the oxide surface layers, followed by the reduction reaction via electron transfer (Godunov et al, 2012). Sahoo et al (2001) studied the leaching of low-grade manganese ore using oxalic acid as reductant in sulphuric acid solution.…”

Section: Introductionmentioning

confidence: 99%

Jiroft refractory manganese ore leaching using oxalic acid as reducing agent in sulfuric acid solution

Sobouti

Shafaat

Abdollahzadeh

2020

Physicochem. Probl. Miner. Process.

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Leaching process of Jiroft refractory manganese ore was investigated. The effects of operating parameters such as liquid to solid ratio, pulp temperature, sulfuric acid concentration, and oxalic acid concentration were studied and the optimization was done through the response surface methodology (RSM) based on central composite design (CCD) model. The recoveries of Mn, Fe and Si were selected as response of design. The optimum condition was determined by ANOVA, indicating that the liquid to solid ratio, oxalic acid concentration and pulp temperature for Mn recovery and liquid to solid ratio, pulp temperature and sulfuric acid concentration for Fe recovery and liquid to solid ratio for Si recovery were the most effective parameters, respectively. Under the optimum conditions of liquid to solid ratio= 11.8%, pulp temperature= 70 o C, sulfuric acid concentration= 40 g/L and oxalic acid concentration= 35 g/L, 71.1%, 4.67% and 0.6% of Mn, Fe and Si were recovered, respectively.

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Influence of oxalic acid on the dissolution kinetics of manganese oxide

Cited by 8 publications

References 2 publications

Band Diagram and Rate Analysis of Thin Film Spinel LiMn₂O₄ Formed by Electrochemical Conversion of ALD‐Grown MnO

Band Diagram and Rate Analysis of Thin Film Spinel LiMn₂O₄ Formed by Electrochemical Conversion of ALD‐Grown MnO

Fungal Mobilization of Selenium in the Presence of Hausmannite and Ferric Oxyhydroxides

Jiroft refractory manganese ore leaching using oxalic acid as reducing agent in sulfuric acid solution

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Influence of oxalic acid on the dissolution kinetics of manganese oxide

Cited by 8 publications

References 2 publications

Band Diagram and Rate Analysis of Thin Film Spinel LiMn2O4 Formed by Electrochemical Conversion of ALD‐Grown MnO

Band Diagram and Rate Analysis of Thin Film Spinel LiMn2O4 Formed by Electrochemical Conversion of ALD‐Grown MnO

Fungal Mobilization of Selenium in the Presence of Hausmannite and Ferric Oxyhydroxides

Jiroft refractory manganese ore leaching using oxalic acid as reducing agent in sulfuric acid solution

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Product

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Band Diagram and Rate Analysis of Thin Film Spinel LiMn₂O₄ Formed by Electrochemical Conversion of ALD‐Grown MnO

Band Diagram and Rate Analysis of Thin Film Spinel LiMn₂O₄ Formed by Electrochemical Conversion of ALD‐Grown MnO