Formation of Fe–Mn–Si oxide and nontronite deposits in hydrothermal fields on the Valu Fa Ridge, Lau Basin

Sun, Zhilei; Zhou, Huaiyang; Glasby, G. P.; Qinye, Yang; Yin, Xijie; Li, Jiwei; Chen, Zhiqiang

doi:10.1016/j.jseaes.2011.08.011

Cited by 39 publications

(19 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…An intriguing aspect of this behavior is that it suggests the cells are able to control the directionality of stalk production, although the mechanism of this is not understood. Similar directional orientation has been observed in other Fe(II)‐oxidizer stalks, from freshwater microbes (Hanert, ) and marine deposits (Sun et al ., , ), and so control of directionality appears common to stalk‐forming Fe(II)‐oxidizers. Thus, in addition to being a biogenicity indicator, stalk directionality provides an important clue about the presence and orientation of the redox gradient, and the relative location of the oxygen source.…”

Section: Discussionmentioning

confidence: 99%

Morphology of biogenic iron oxides records microbial physiology and environmental conditions: toward interpreting iron microfossils

et al. 2013

View full text Add to dashboard Cite

Despite the abundance of Fe and its significance in Earth history, there are no established robust biosignatures for Fe(II)-oxidizing micro-organisms. This limits our ability to piece together the history of Fe biogeochemical cycling and, in particular, to determine whether Fe(II)-oxidizers played a role in depositing ancient iron formations. A promising candidate for Fe(II)-oxidizer biosignatures is the distinctive morphology and texture of extracellular Fe(III)-oxyhydroxide stalks produced by mat-forming microaerophilic Fe(II)-oxidizing micro-organisms. To establish the stalk morphology as a biosignature, morphologic parameters must be quantified and linked to the microaerophilic Fe(II)-oxidizing metabolism and environmental conditions. Toward this end, we studied an extant model organism, the marine stalk-forming Fe(II)-oxidizing bacterium, Mariprofundus ferrooxydans PV-1. We grew cultures in flat glass microslide chambers, with FeS substrate, creating opposing oxygen/Fe(II) concentration gradients. We used solid-state voltammetric microelectrodes to measure chemical gradients in situ while using light microscopy to image microbial growth, motility, and mineral formation. In low-oxygen (2.7-28 μm) zones of redox gradients, the bacteria converge into a narrow (100 μm-1 mm) growth band. As cells oxidize Fe(II), they deposit Fe(III)-oxyhydroxide stalks in this band; the stalks orient directionally, elongating toward higher oxygen concentrations. M. ferrooxydans stalks display a narrow range of widths and uniquely biogenic branching patterns, which result from cell division. Together with filament composition, these features (width, branching, and directional orientation) form a physical record unique to microaerophilic Fe(II)-oxidizer physiology; therefore, stalk morphology is a biosignature, as well as an indicator of local oxygen concentration at the time of formation. Observations of filamentous Fe(III)-oxyhydroxide microfossils from a ~170 Ma marine Fe-Si hydrothermal deposit show that these morphological characteristics can be preserved in the microfossil record. This study demonstrates the potential of morphological biosignatures to reveal microbiology and environmental chemistry associated with geologic iron formation depositional processes.

show abstract

Section: Discussionmentioning

confidence: 99%

Morphology of biogenic iron oxides records microbial physiology and environmental conditions: toward interpreting iron microfossils

et al. 2013

View full text Add to dashboard Cite

show abstract

“…The deposition process was conducted through a hydrothermal process, which facilitates the formation of Mn O Si composite interfaces. As revealed in various geological settings, [ 34 ] the formation of Mn Si oxides is facile under hydrothermal conditions. The precipitated oxide composite beads were fi nally treated with an alkaline solution to partially remove SiO 2 to produce a porous interior, which can increase the solid-electrolyte contact area.…”

Section: Resultsmentioning

confidence: 99%

“…The nature of the Mn ions within the bulk of the MnO 2 nanodomains may be probed based on the Mn k -edge energy and the profi le of the near-edge absorption spectrum. As indicated by the absorption spectra of standard Mn oxides shown in Figure 10 a, the Mn k -edge energy in general decreases with reducing Mn valence, [ 25,34,35 ] and some of the Mn oxides, for instance Mn 3 O 4 and MnO, exhibit unique spectrum profi les that are distinctly different from those of the other Mn oxides.…”

Section: Charge-transfer Kinetic Mechanismsmentioning

confidence: 99%

Spatially Confined MnO₂ Nanostructure Enabling Consecutive Reversible Charge Transfer from Mn(IV) to Mn(II) in a Mixed Pseudocapacitor‐Battery Electrode

Weng

Pan

Lee

et al. 2015

Advanced Energy Materials

View full text Add to dashboard Cite

where C is the specifi c capacitance, Δ V is the operating voltage range, and Q is the specifi c charge-storage capacity. For improving the specifi c energy, both the charge-storage capacity and operating potential window (OPW) of the pseudocapacitor electrodes should be maximized.First reported by Goodenough and coworkers, [ 13,14 ] MnO 2 has attracted substantial attention as a promising pseudocapacitor electrode material [ 15 ] because of its low cost, natural abundance, and environmental friendliness. The use of aqueous neutral electrolytes in MnO 2 -based pseudocapacitors, in particular, provides superior device safety compared with those requiring either organic electrolytes or strong acidic (such as for RuO 2 ) [ 16 ] aqueous electrolytes.Numerous studies have recently developed MnO 2 electrodes either in thin fi lm [17][18][19] or as composites with various materials, such as graphene, [ 20,21 ] porous carbon foam, [22][23][24] and SiC, [ 25 ] to increase the solid-electrolyte contact area and tailor the electrode architectures for enhanced capacity and power performances. [17][18][19][20][21][22][23][24][25] However, until now, the charge-storage capacity of MnO 2 -based pseudocapacitors has been limited to a small fraction of oneelectron transfer between Mn(IV) and Mn(III) ions per unit formula of MnO 2 ( e − /MnO 2 ) with an OPW of ≤1 V. [ 26 ] Only in rare cases of either extremely low oxide loading [ 22,27,28 ] or mixed valences, [ 21 ] the MnO 2 electrodes have been reported to afford a specifi c charge capacity close to 1 e − /MnO 2 . To exceed this charge-storage limit, new strategies that enable reversible electron transfer between Mn ions of lower valences are required, and this also means that the OPW must be extended to lower potentials.For an MnO 2 electrode in an aqueous electrolyte, the upper limit of its OPW is typically not related to the intrinsic properties of the oxide; however, it is limited by either water (solvent) or electrolyte anion (e.g., Cl − ) oxidation, [ 29 ] or current collector oxidation, [ 30 ] or the combination of both. For example, water oxidation causes oxygen bubbling, which may lead to active-layer loosening, and current collector oxidation causes an increase in the interfacial resistance between the active layer and the current collector. By contrast, the lower limit of the OPW of an MnO 2 electrode is closely related to the fundamental electrochemical Mn oxides are highly important electrode materials for aqueous electrochemical energy storage devices, including batteries and supercapacitors. Although MnO 2 is a promising pseudocapacitor material because of its outstanding rate and capacity performance, its electrochemical instability in aqueous electrolyte prevents its use at low electrochemical potential. Here, the possibility of stabilizing MnO 2 electrode using SiO 2 -confi ned nanostructure is demonstrated. Remarkably, an exceptionally good electrochemical stability under large negative polarization in aqueous (Li 2 SO 4 ) electrolyte, usually unattainable fo...

show abstract

“…Besides this, the observation that two‐generation structure, Fe‐rich core of filaments embedded in the Si‐rich parts, and existence of the Fe‐O‐Si and Si‐O‐Si bonds, all suggest that the mechanism involved in silica precipitation is representing a later generation with two‐step process. This finding was also consistent with the previous finding [ Beveridge and Fyfe , ; Sun et al ., ].…”

Section: Discussionmentioning

confidence: 99%

Generation of hydrothermal Fe‐Si oxyhydroxide deposit on the Southwest Indian Ridge and its implication for the origin of ancient banded iron formations

Sun

Huang

et al. 2015

JGR Biogeosciences

Self Cite

View full text Add to dashboard Cite

Modern hydrothermal Fe-Si oxyhydroxide deposits are now known to be analogues to ancient siliceous iron formations. In this study, samples of Fe-Si oxyhydroxide deposits were collected from hydrothermal field on the Southwest Indian Ridge. An investigation of mineralization in these deposits was carried out based on a series of mineralogical and morphological methods. X-ray diffraction and selected area electron diffraction analysis show that amorphous opal and poorly crystalline ferrihydrite are the major minerals. Furthermore, some typical filament structures detected by scanning electronic microscopy examinations, probably indicating the presence of Fe-oxidizing bacteria (FeOB), are pervasive with the main constituents being Fe, Si, P, and C. We thus believe that chemolithoautotrophic FeOB play a significant role in the formation of Fe oxyhydroxide which can effectively oxidize reduced Fe(II) sourced from hydrothermal fluids. Precipitation of amorphous silica, in contrast, is only a passive process with the Fe oxyhydroxide acting as a template. The distinct microlaminae structure alternating between the Fe-rich and Si-rich bands was observed in our samples for the first time in modern seafloor hydrothermal systems. We propose that its formation was due to the episodic temperature variation of the hydrothermal fluid which controls the biogenic Fe oxyhydroxide formation and passive precipitation of silica in this system. Our results might provide a clue for the formation mechanism of ancient banded iron formations.

show abstract

Formation of Fe–Mn–Si oxide and nontronite deposits in hydrothermal fields on the Valu Fa Ridge, Lau Basin

Cited by 39 publications

References 78 publications

Morphology of biogenic iron oxides records microbial physiology and environmental conditions: toward interpreting iron microfossils

Morphology of biogenic iron oxides records microbial physiology and environmental conditions: toward interpreting iron microfossils

Spatially Confined MnO₂ Nanostructure Enabling Consecutive Reversible Charge Transfer from Mn(IV) to Mn(II) in a Mixed Pseudocapacitor‐Battery Electrode

Generation of hydrothermal Fe‐Si oxyhydroxide deposit on the Southwest Indian Ridge and its implication for the origin of ancient banded iron formations

Contact Info

Product

Resources

About

Formation of Fe–Mn–Si oxide and nontronite deposits in hydrothermal fields on the Valu Fa Ridge, Lau Basin

Cited by 39 publications

References 78 publications

Morphology of biogenic iron oxides records microbial physiology and environmental conditions: toward interpreting iron microfossils

Morphology of biogenic iron oxides records microbial physiology and environmental conditions: toward interpreting iron microfossils

Spatially Confined MnO2 Nanostructure Enabling Consecutive Reversible Charge Transfer from Mn(IV) to Mn(II) in a Mixed Pseudocapacitor‐Battery Electrode

Generation of hydrothermal Fe‐Si oxyhydroxide deposit on the Southwest Indian Ridge and its implication for the origin of ancient banded iron formations

Contact Info

Product

Resources

About

Spatially Confined MnO₂ Nanostructure Enabling Consecutive Reversible Charge Transfer from Mn(IV) to Mn(II) in a Mixed Pseudocapacitor‐Battery Electrode