scholarly journals Microbial Reduction of Metal-Organic Frameworks Enables Synergistic Chromium Removal

2018 ◽  
Author(s):  
Sarah K. Springthorpe ◽  
Christopher M. Dundas ◽  
Benjamin K. Keitz
Keyword(s):  
Metal Oxides ◽  
Metal Organic Frameworks ◽  
Reduction Rate ◽  
Shewanella Oneidensis ◽  
Particle Morphology ◽  
Microbial Reduction ◽  
Pollutant Removal ◽  
Extracellular Electron Transfer ◽  
Promising Alternative ◽  
Metal Organic

AbstractMicrobe-material redox interactions underpin many emerging technologies, including bioelectrochemical cells and bioremediation. However, commonly utilized material substrates, such as metal oxides, suffer from a lack of tunability and can be challenging to characterize. In contrast, metal-organic frameworks, a class of porous materials, exhibit well-defined structures, high crystallinity, large surface areas, and extensive chemical tunability. Here, we report that metal-organic frameworks can support the growth of the electroactive bacterium Shewanella oneidensis. Specifically, we demonstrate that Fe(III)-containing frameworks, MIL-100 and Fe-BTC, can be reduced by the bacterium via its extracellular electron transfer pathways and that reduction rate/extent is tied to framework structure, surface area, and particle morphology. In a practical application, we show that cultures containing S. oneidensis and reduced frameworks can remediate lethal concentrations of Cr(VI), and that pollutant removal exceeds the performance of either component in isolation or bioreduced iron oxides. Repeated cycles of Cr(VI) dosing had little effect on bacterial viability or Cr(VI) adsorption capacity, demonstrating that the framework confers protection to the bacteria and that no regenerative step is needed for continued bioremediation. In sum, our results show that metal-organic frameworks can serve as microbial respiratory substrates and suggest that they may offer a promising alternative to metal oxides in applications seeking to combine the advantages of bacterial metabolism and synthetic materials.

scholarly journals Microbial reduction of metal-organic frameworks enables synergistic chromium removal

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Sarah K. Springthorpe ◽  
Christopher M. Dundas ◽  
Benjamin K. Keitz
Keyword(s):  
Metal Oxides ◽  
Metal Organic Frameworks ◽  
Shewanella Oneidensis ◽  
Microbial Reduction ◽  
Pollutant Removal ◽  
Inorganic Materials ◽  
Surface Areas ◽  
Synthetic Materials ◽  
Metal Organic ◽  
Multiple Cycles

AbstractRedox interactions between electroactive bacteria and inorganic materials underpin many emerging technologies, but commonly used materials (e.g., metal oxides) suffer from limited tunability and can be challenging to characterize. In contrast, metal-organic frameworks exhibit well-defined structures, large surface areas, and extensive chemical tunability, but their utility as microbial substrates has not been examined. Here, we report that metal-organic frameworks can support the growth of the metal-respiring bacterium Shewanella oneidensis, specifically through the reduction of Fe(III). In a practical application, we show that cultures containing S. oneidensis and reduced metal-organic frameworks can remediate lethal concentrations of Cr(VI) over multiple cycles, and that pollutant removal exceeds the performance of either component in isolation or bio-reduced iron oxides. Our results demonstrate that frameworks can serve as growth substrates and suggest that they may offer an alternative to metal oxides in applications seeking to combine the advantages of bacterial metabolism and synthetic materials.

A direct solvent-free conversion approach to prepare mixed-metal metal–organic frameworks from doped metal oxides

2021 ◽  
Vol 57 (29) ◽  
pp. 3587-3590
Author(s):  
Beili Yi ◽  
Haojie Zhao ◽  
Yue Zhang ◽  
Xiaomeng Si ◽  
Guanqun Zhang ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Metal Organic Frameworks ◽  
Solvent Free ◽  
Mixed Metal ◽  
Synthesis Strategy ◽  
Metal Metal ◽  
Metal Organic

We propose a novel solvent-free conversion strategy of Pt–ZnO to Pt-ZIF-8. This synthesis strategy may facilitate the discovery of MMOFs that have not been reported previously.

Impact of Graphitic Structures in Pyrogenic Carbon on Microbial Reduction of Ferrihydrite

2021 ◽  
Author(s):  
wentao yu ◽  
baoliang chen
Keyword(s):  
Electron Transfer ◽  
Pyrolysis Temperature ◽  
Shewanella Oneidensis ◽  
Exchange Capacity ◽  
Microbial Reduction ◽  
Systematic Evaluation ◽  
Extracellular Electron Transfer ◽  
Pyrogenic Carbon ◽  
The Impact

<p>Pyrogenic carbon plays important roles in microbial reduction of ferrihydrite by shuttling electrons in the extracellular electron transfer (EET) processes. Despite its importance, a full assessment on the impact of graphitic structures in pyrogenic carbon on microbial reduction of ferrihydrite has not been conducted. This study is a systematic evaluation of microbial ferrihydrite reduction by Shewanella oneidensis MR-1 in the presence of pyrogenic carbon with various graphitization extents. The results showed that the rates and extents of microbial ferrihydrite reduction were significantly enhanced in the presence of pyrogenic carbon, and increased with increasing pyrolysis temperature. Combined spectroscopic and electrochemical analyses suggested that the rate of microbial ferrihydrite reduction were dependent on the electrical conductivity of pyrogenic carbon (i.e., graphitization extent), rather than the electron exchange capacity. The key role of graphitic structures in pyrogenic carbon in mediating EET was further evidenced by larger microbial electrolysis current with pyrogenic carbon prepared at higher pyrolysis temperatures. This study provides new insights into the electron transfer in the pyrogenic carbon-mediated microbial reduction of ferrihydrite.</p>

Metal oxides and metal organic frameworks for the photocatalytic degradation: A review

2020 ◽  
Vol 8 (3) ◽  
pp. 103726 ◽  
Author(s):  
Sanjeev Gautam ◽  
Harshita Agrawal ◽  
Manisha Thakur ◽  
Ali Akbari ◽  
Hemam Sharda ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Photocatalytic Degradation ◽  
Metal Organic Frameworks ◽  
Metal Organic

Sequencing of metals in multivariate metal-organic frameworks

Science ◽  
2020 ◽  
Vol 369 (6504) ◽  
pp. 674-680 ◽  
Author(s):  
Zhe Ji ◽  
Tong Li ◽  
Omar M. Yaghi
Keyword(s):  
Metal Oxides ◽  
Atom Probe Tomography ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Molar Fraction ◽  
Atom Probe ◽  
Synthesis Temperature ◽  
Sequence Type ◽  
High Tolerance ◽  
Metal Organic

We mapped the metal sequences within crystals of metal-oxide rods in multivariate metal-organic framework–74 containing mixed combinations of cobalt (Co), cadmium (Cd), lead (Pb), and manganese (Mn). Atom probe tomography of these crystals revealed the presence of heterogeneous spatial sequences of metal ions that we describe, depending on the metal and synthesis temperature used, as random (Co, Cd, 120°C), short duplicates (Co, Cd, 85°C), long duplicates (Co, Pb, 85°C), and insertions (Co, Mn, 85°C). Three crystals were examined for each sequence type, and the molar fraction of Co among all 12 samples was observed to vary from 0.4 to 0.9, without changing the sequence type. Compared with metal oxides, metal-organic frameworks have high tolerance for coexistence of different metal sizes in their rods and therefore assume various metal sequences.

scholarly journals Cobalt-Based Metal-Organic Frameworks and Their Derivatives for Hydrogen Evolution Reaction

2020 ◽  
Vol 8 ◽  
Author(s):  
Wenjuan Han ◽  
Minhan Li ◽  
Yuanyuan Ma ◽  
Jianping Yang
Keyword(s):  
Hydrogen Production ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Hydrogen Evolution Reaction ◽  
Alternative Energy ◽  
Metal Organic Frameworks ◽  
Electrochemical Performances ◽  
Promising Alternative ◽  
Metal Organic ◽  
Electrochemical Water Splitting

Hydrogen has been considered as a promising alternative energy to replace fossil fuels. Electrochemical water splitting, as a green and renewable method for hydrogen production, has been drawing more and more attention. In order to improve hydrogen production efficiency and lower energy consumption, efficient catalysts are required to drive the hydrogen evolution reaction (HER). Cobalt (Co)-based metal-organic frameworks (MOFs) are porous materials with tunable structure, adjustable pores and large specific surface areas, which has attracted great attention in the field of electrocatalysis. In this review, we focus on the recent progress of Co-based metal-organic frameworks and their derivatives, including their compositions, morphologies, architectures and electrochemical performances. The challenges and development prospects related to Co-based metal-organic frameworks as HER electrocatalysts are also discussed, which might provide some insight in electrochemical water splitting for future development.

Metal and metal oxidenanoparticle synthesis from metal organic frameworks (MOFs): finding the border of metal and metal oxides

Nanoscale ◽  
2012 ◽  
Vol 4 (2) ◽  
pp. 591-599 ◽  
Author(s):  
Raja Das ◽  
Pradip Pachfule ◽  
Rahul Banerjee ◽  
Pankaj Poddar
Keyword(s):  
Metal Oxides ◽  
Metal Organic Frameworks ◽  
Metal Organic

scholarly journals Encoding Metal-Cation Arrangements in Metal-Organic Frameworks for Programming the Composition of Electrocatalytically Active Multi-Metal Oxides

2018 ◽  
Author(s):  
Celia Castillo-Blas ◽  
María de las Nieves López-Salas ◽  
María C. Gutiérrez ◽  
Inés Puente-Orench ◽  
Enrique Gutiérrez-Puebla ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Metal Organic Frameworks ◽  
Reduction Reaction ◽  
Methanol Tolerance ◽  
Present Contribution ◽  
Calcination Process ◽  
Secondary Building Units ◽  
Metal Organic ◽  
Synthetic Methodologies ◽  
Metal Ratios

In the present contribution, we report how through the use of metal-organic frameworks (MOFs) composed of addressable combinations of up to four different metal elements it is possible to program the composition of multi-metal oxides, which are not attainable by other synthetic methodologies. Thus, due to the ability to distribute multiple metal cations at specific locations in the MOF secondary building units it is possible to code and transfer selected metal ratios to multi-metal oxides with novel, desired compositions through a simple calcination process. The demonstration of an enhancement in the electrocatalytic activity of new oxides by pre-adjusting the metal ratios is here reported for the oxygen reduction reaction, for which activity values comparable to commercial Pt/C catalysts are reached, while showing long stability and methanol tolerance.

scholarly journals A novel zinc sulfide impregnated carbon composite derived from zeolitic imidazolate framework-8 for sodium-ion hybrid solid-state flexible capacitors

2021 ◽  
Author(s):  
Vishal Shrivastav ◽  
Shashank Sundriyal ◽  
Priyanshu Goel ◽  
Avishek Saha ◽  
Umesh K. Tiwari ◽  
...  
Keyword(s):  
Solid State ◽  
Specific Surface ◽  
Metal Oxides ◽  
Zinc Sulfide ◽  
Metal Organic Frameworks ◽  
Carbon Composite ◽  
High Specific Surface Area ◽  
Sodium Ion ◽  
Zeolitic Imidazolate Framework ◽  
Metal Organic

The pyrolysis of metal–organic frameworks (MOFs) is an easy approach to prepare metal oxides as well as nanoporous carbon with high specific surface area.

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