Nano zero valent iron encapsulated in graphene oxide for reducing uranium

Huiping, Tang; Cheng, Wencai; Yi, Yunpeng; Ding, Congcong; Nie, Xiaoqin

doi:10.1016/j.chemosphere.2021.130229

Cited by 25 publications

(7 citation statements)

References 54 publications

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“…The diffraction peaks at 44.99° and 65.21° correspond to different crystal planes of the zero‐valent iron, indicating that NRI was successfully synthesized. In addition, it can be seen from SEM and TEM that NRI are spherical nanoparticles, which often exist in the form of chain‐like aggregates due to magnetic attraction, colloidal aggregation and surface hydroxides (Figure 1a and b and Figure S1b–d) [8c, 9c] . The HRTEM images (Figure 1c) of NRI further indicate that the lattices with spacing of 0.202 nm correspond to (110) crystal planes of Fe, which is consistent with the results reported in the literature [15] .…”

Section: Resultsmentioning

confidence: 99%

Electrochemical‐Mediated Regenerable Fe^II Active Sites for Efficient Uranium Extraction at Ultra‐Low Cell Voltage

Wang

Song

et al. 2023

Angew Chem Int Ed

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Nano‐reduced iron (NRI) is a promising uranium adsorbent due to its strong reducibility and good selectivity, but it still faces the challenges of slow kinetics, limited and non‐renewable active sites. In this work, we realized high efficiency uranium extraction under ultra‐low cell voltage (−0.1 V) in seawater with 20 ppm UO2(NO3)2 solution by coupling electrochemical mediated FeII/FeIII redox and uranium extraction. The adsorption capacity and extraction efficiency of NRI after electrochemical uranium extraction (EUE) could reach 452 mg/g and 99.1 %, respectively. Combined with quasi‐operando/operando characterization technologies, we clarified the mechanism of EUE and revealed that continuously regenerating FeII active sites by electroreduction could significantly enhance the property of EUE. This work here provides a new electrochemical mediated and low energy consumption uranium extraction strategy which also provides a reference for other metal resource recovery.

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Section: Resultsmentioning

confidence: 99%

Electrochemical‐Mediated Regenerable Fe^II Active Sites for Efficient Uranium Extraction at Ultra‐Low Cell Voltage

Wang

Song

et al. 2023

Angew Chem Int Ed

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“…Combined with operando Raman spectroscopy and quasi-operando XPS analysis, the EUE mechanism of S-NRI can be as follows (Figure ): (1) U(VI)O 2 2+ was electroadsorbed onto the surface of S-NRI and coordinated with Fe–SO 4 2– under an electric field. (2) U(VI)O 2 2+ was spontaneously reduced by Fe(0/II) on the surface of S-NRI to form low valent uranium oxides (U x O y ) and Fe(III) . (3) Finally, as-formed Fe(III) on the surface of S-NRI was electroreduced to Fe(II) and (4) then, as-formed Fe(II) continued to reduce U(VI) to U(IV) and was oxidized to Fe(III), and the cycle then repeated itself.…”

Section: Resultsmentioning

confidence: 99%

“…Combined with operando Raman spectroscopy and quasioperando XPS analysis, the EUE mechanism of S-NRI can be as follows (Figure 4): ( 1 was spontaneously reduced by Fe(0/II) on the surface of S-NRI to form low valent uranium oxides (U x O y ) and Fe(III). 26 (3) Finally, asformed Fe(III) on the surface of S-NRI was electroreduced to Fe(II) and ( 4) then, as-formed Fe(II) continued to reduce U(VI) to U(IV) and was oxidized to Fe(III), and the cycle then repeated itself. We further evaluated the EUE property of the as-synthesized S-NRI adsorbent in a two-electrode system.…”

Section: +mentioning

confidence: 99%

Strengthening Fe(II)/Fe(III) Dynamic Cycling by Surface Sulfation to Achieve Efficient Electrochemical Uranium Extraction at Ultralow Cell Voltage

Wang,

Song,

Wei

et al. 2023

Environ. Sci. Technol.

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Electrochemically mediated Fe(II)/Fe(III) redox-coupled uranium extraction can efficiently reduce the cell voltage of electrochemical uranium extraction (EUE). How to regulate the surface structure to enhance the uranium acyl ion adsorption capacity and strengthen the Fe(II)/Fe(III) redox cycle process is crucial for EUE. In this work, we developed surface sulfated nanoreduced iron (S-NRI) for EUE and exhibited improved properties for EUE at an ultralow cell voltage (−0.1 V). Compared with a nanoreduced iron (NRI) adsorbent, S-NRI displayed faster electrochemical extraction kinetics properties and higher extraction efficiency and capacity for uranium. In a more complex seawater electrolyte containing uranyl ion concentration ranging from 1 to 20 ppm, the removal efficiency could reach almost ∼100% after EUE for 24 h. At a higher 50 ppm uranium acyl ion concentration in a seawater electrolyte, S-NRI exhibited higher extraction capacity (755.03 mg/g), which is better than 528.53 mg/g of NRI at a cell voltage of −0.1 V. Outstanding EUE property could be attributed to the fact that sulfate species (M−SO 4 2− ) on the S-NRI surface not only enhanced selective adsorption of uranyl ions but also strengthened the Fe(II)/Fe(III) redox cycle, which accelerated electron transfer between Fe(II) and U(VI), promoted the regeneration of Fe(II) active sites, and finally enhanced the EUE property.

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“…One of the most significant drawbacks of iron nanoparticles is the tendency towards agglomeration, which leads to a decrease in the specific surface area and, thus, to a reduction in the reactivity. To overcome this disadvantage, several support materials for nZVI have been used over time, such as magnesium oxide [95,96], biochar [97][98][99], activated carbon [100][101][102], chitosan fibres [103], hydrochar [104], plastics-derived carbon [105], zeolite [106,107], montmorillonite [108][109][110], bentonite [111][112][113], expanded graphite [114], graphene, and graphene oxide [115][116][117][118][119]. These supported nZVIs were used for the treatment of numerous contaminants, such as heavy metals, inorganic pollutants, and organic compounds.…”

Section: Supported Nzvimentioning

confidence: 99%

Nitrate Removal by Zero-Valent Metals: A Comprehensive Review

et al. 2022

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Nitrate is a widespread water contaminant that can pose environmental and health risks. Various conventional techniques can be applied for the removal of nitrate from water and wastewater, such as biological denitrification, ion exchange, nanofiltration, and reverse osmosis. Compared to traditional methods, the chemical denitrification through zero-valent metals offers various advantages, such as lower costs, simplicity of management, and high efficiencies. The most utilized material for chemical denitrification is zero-valent iron (ZVI). Aluminium (ZVA), magnesium (ZVM), copper (ZVC), and zinc (ZVZ) are alternative zero-valent metals that are studied for the removal of nitrate from water as well as from aqueous solutions. To the best of our knowledge, a comprehensive work on the use of the various zero-valent materials that are employed for the removal of nitrate is still missing. Therefore, in the present review, the most recent papers concerning the use of zero-valent materials for chemical denitrification were analysed. The studies that dealt with zero-valent iron were discussed by considering microscopic (mZVI) and nanoscopic (nZVI) forms. For each Fe0 form, the effects of the initial pH, the presence or absence of dissolved oxygen, the initial nitrate concentration, the temperature, and the dissolved ions on the nitrate removal process were separately evaluated. Finally, the different materials that were employed as support for the nanoparticles were examined. For the other zero-valent metals tested, a detailed description of the works present in the literature was carried out. A comparison of the various features that are related to each considered material was also made.

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Nano zero valent iron encapsulated in graphene oxide for reducing uranium

Cited by 25 publications

References 54 publications

Electrochemical‐Mediated Regenerable Fe^II Active Sites for Efficient Uranium Extraction at Ultra‐Low Cell Voltage

Electrochemical‐Mediated Regenerable Fe^II Active Sites for Efficient Uranium Extraction at Ultra‐Low Cell Voltage

Strengthening Fe(II)/Fe(III) Dynamic Cycling by Surface Sulfation to Achieve Efficient Electrochemical Uranium Extraction at Ultralow Cell Voltage

Nitrate Removal by Zero-Valent Metals: A Comprehensive Review

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Nano zero valent iron encapsulated in graphene oxide for reducing uranium

Cited by 25 publications

References 54 publications

Electrochemical‐Mediated Regenerable FeII Active Sites for Efficient Uranium Extraction at Ultra‐Low Cell Voltage

Electrochemical‐Mediated Regenerable FeII Active Sites for Efficient Uranium Extraction at Ultra‐Low Cell Voltage

Strengthening Fe(II)/Fe(III) Dynamic Cycling by Surface Sulfation to Achieve Efficient Electrochemical Uranium Extraction at Ultralow Cell Voltage

Nitrate Removal by Zero-Valent Metals: A Comprehensive Review

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Electrochemical‐Mediated Regenerable Fe^II Active Sites for Efficient Uranium Extraction at Ultra‐Low Cell Voltage

Electrochemical‐Mediated Regenerable Fe^II Active Sites for Efficient Uranium Extraction at Ultra‐Low Cell Voltage