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Open accessJournal ArticleDOI: 10.1021/ACSESTENGG.0C00268

Removal of Radionuclides from Aqueous Solution by Manganese Dioxide-Based Nanomaterials and Mechanism Research: A Review

04 Mar 2021-Vol. 1, Iss: 4, pp 685-705
Abstract: Manganese dioxide (MnO2) is an environmentally friendly metal oxide. The characteristics of diverse morphology, rich crystal forms, and controllable particle size make MnO2 flexibly adaptive to mul...

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Topics: Manganese (53%)
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28 results found


Journal ArticleDOI: 10.1007/S11356-021-14835-0
Renrong Liu1, Hai Wang1, Li Han1, Baowei Hu1  +1 moreInstitutions (1)
Abstract: The novel biochar supported by starch and nanoscale iron sulfide (SFeS@Biochar) composites were successfully prepared through coupling of biochar derived from peanut shell with nanoscale ferrous sulfide and starch under nitrogen atmosphere. It had the advantages of biochar, starch, and nanoscale ferrous sulfide. Therefore, it could overcome some shortcomings. The nanoscale ferrous sulfide particles and starch were thought to be loaded successfully on the surface of the biochar by SEM, EDS, BET, XRD, FT-IR, and XPS techniques. High uptake capacity of U(VI) by SFeS@Biochar could be attributed to reactive reaction of FeS nanoparticles and adsorptive of a lot of functional groups. The proposed reaction mechanisms of the U(VI) uptake by SFeS@Biochar were electrostatic attraction, surface complexation, precipitation, and reductive reaction. It also might be an improved environmentally friendly material for U(VI) removal.

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Topics: Biochar (59%), Sulfide (57%), Iron sulfide (54%) ... read more

8 Citations


Journal ArticleDOI: 10.1016/J.JECE.2021.105687
Eman A. Gendy1, Eman A. Gendy2, Jerosha Ifthikar1, Jawad K. Ali1  +5 moreInstitutions (2)
Abstract: Covalent organic frameworks (COFs) have demonstrated a great potential in the removal of heavy metals due to its high adsorption capacity, large surface area, tunable porosity, porous structure, and recyclability. These features give COFs advantages over traditional adsorbents. The occurrence of heavy metals in surface and groundwater above the maximum acceptable limit poses a great threat not only for human health but also for the environment. The elimination of these large amounts of heavy metals serves as a significant challenge. Hence, this review complies the recent investigations on COFs as a superior material in the removal of heavy metals from water considering various environmental parameters as well as the recycling process using different regeneration agents. The selectivity and sensitivity of COFs and COF-based materials were elucidated. Moreover, the different adsorption mechanisms of heavy metals by COF-based materials are critically discussed. The chemical structures and functional groups play a significant role in enhancing the removal efficiency of heavy metals. In addition, personal insights based on the interaction mechanism of COFs and various functional groups into future research prospects. We believe that this review paper can motivate more researchers to use COFs for water remediation.

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6 Citations


Journal ArticleDOI: 10.1016/J.CEJ.2021.131538
Ying Wang1, Zaiwen Lin1, Qi Liu1, Qi Liu2  +6 moreInstitutions (2)
Abstract: The uranium(VI) (U(VI)) extraction from seawater was crucial for future energy problems such as increasingly depleted fossil fuels and serious environmental pollution, and it could improve the current situation of limited U(VI) reserves on land. In this study, the natural material bamboo strips (BS) were utilized due to the flexibility and richness of various functional groups, and the amidoximized bamboo strips (AOBS) could be directly prepared by a simple one-step method. The amidoximation of materials not only adjusted the optimal adsorption pH from 4 to 6, but also advanced the hydrophilicity, speeded up the reaction rate (adsorption equilibrium within 1 h, about 0.17 times of BS), and increased the adsorption capacity (qe = 268.41 mg g−1 at pH = 6, about 1.7 times of BS). Importantly, the AOBS maintained its initial stitchability through flexibility adjustment, and was woven into a macro-shaped adsorbent (AOBS-M). After being placed in the Yellow Sea basin for 30 days, approximately 44.75 g of crude U(VI) (U(VI) content = 40.45 mg) was obtained (qe = 0.97 mg g−1), and it showed the excellent selectivity for U(VI). The AOBS-M not only overcame the problem that the existing adsorption materials were difficult to achieve macroscopic large-area molding, but also realized the flexibility adjustment during the modification process by controlling the reaction conditions, and promoted the industrial development of U(VI) extraction from seawater.

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Topics: Environmental pollution (53%), Adsorption (51%)

4 Citations


Journal ArticleDOI: 10.1016/J.CEJ.2021.130812
Nian-Dan Zhao1, Yan Wang2, Xiao-Hang Zou3, Wei-Ming Yin3  +3 moreInstitutions (3)
Abstract: The utilization of renewable biomass cellulose in treating pollution of heavy metal ions (HMIs) is one of overarching and appealing strategies, because it simultaneously satisfies sustainable development and resolves ever-increasing environmental issue. In this regard, the composite cellulose@Mg(OH)2 was prepared via a facile method and explored for its use as water treatment agent. It is demonstrated that the smaller and thinner hexagonal Mg(OH)2 flakes are constructed onto the cellulose substrate by self-assembling; two components are chemically coupled via hydrogen bonds and Mg-Oc (cellulose oxygen) dative bonds; what’s more, the coupling of cellulose with Mg(OH)2 (1 0 1) facet is much more preferential than with (0 0 1) facet. The resultant composite material shows remarkable HMI removal performance: large capacities of 734.9, 595.8 and 1473.1 mg g−1 for Cd2+, Cu2+ and Pb2+, respectively. Further assisted by good shaping property of the cellulose substrate, the composite is capable of being made into filter, which practically separates HMIs and purifies wastewater with high removal efficiency (99.99%) for Cd2+ even after operating for 110 days and potable water can be obtained. The mechanism is delineated with removal models and characterizations of HMI-recovered products.

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4 Citations


Journal ArticleDOI: 10.1016/J.CHEMOSPHERE.2021.132313
Zhe Wang1, Lingyu Zhang1, Kangjie Zhang1, Yuexiang Lu2  +4 moreInstitutions (3)
01 Jan 2022-Chemosphere
Abstract: Radioactive ions with high-heat release or long half-life could cause long-term influence on environment and they might enter the food chain to damage human body for their toxicity and radioactivity. It is of great importance to develop methods and materials to detect and remove radioactive ions. Carbon dots and their composite materials has been applied widely in many fields due to their plentiful raw materials, facile synthesis and functional process, unique optical property and abundant functional groups. This comprehensive review focuses on the preparation of CDs and composite materials for the detection and adsorption of radioactive ions. Firstly, the recent-developed synthetic methods for CDs were summarized briefly, including hydrothermal/solvothermal, microwave, electrochemistry, microplasma, chemical oxidation methods, focusing on the influence of CDs properties. Secondly, the synthetic methods for CDs composite materials were classified to four categories and summarized generally. Thirdly, the application of CDs for radioactive ions detection and adsorption were explored and concluded including uranium, iodine, europium, strontium, samarium et al. Finally, the detection and adsorption mechanism for radioactive ions were searched and the perspective and outlook of CDs for detection and adsorption radioactive ions have been proposed based on our understanding.

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Topics: Adsorption (50%)

2 Citations


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110 results found


Journal ArticleDOI: 10.1016/J.JHAZMAT.2011.10.016
Ming Hua1, Shujuan Zhang1, Bingcai Pan1, Weiming Zhang1  +2 moreInstitutions (1)
Abstract: Nanosized metal oxides (NMOs), including nanosized ferric oxides, manganese oxides, aluminum oxides, titanium oxides, magnesium oxides and cerium oxides, provide high surface area and specific affinity for heavy metal adsorption from aqueous systems. To date, it has become a hot topic to develop new technologies to synthesize NMOs, to evaluate their removal of heavy metals under varying experimental conditions, to reveal the underlying mechanism responsible for metal removal based on modern analytical techniques (XAS, ATR-FT-IR, NMR, etc.) or mathematical models, and to develop metal oxide-based materials of better applicability for practical use (such as granular oxides or composite materials). The present review mainly focuses on NMOs’ preparation, their physicochemical properties, adsorption characteristics and mechanism, as well as their application in heavy metal removal. In addition, porous host supported NMOs are particularly concerned because of their great advantages for practical application as compared to the original NMOs. Also, some magnetic NMOs were included due to their unique separation performance.

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Topics: Oxide (50%)

1,562 Citations


Journal ArticleDOI: 10.1002/ADMA.200701231
Jinbo Fei1, Yue Cui1, Xuehai Yan1, Wei Qi1  +4 moreInstitutions (2)
04 Feb 2008-Advanced Materials
Abstract: Manganese oxides are of considerable importance in technological applications, including ion-exchange, molecular adsorption, catalysis, and electrochemical supercapacitors owing to their structural flexibility combined with novel chemical and physical properties. Up to now, various nanostructures of MnO2, such as nanoparticles, [6] nanorods/-belts/-wires/-tubes/fibers, nanosheets, mesoporous/molecular sieves and branched structures, urchins/orchids, and other hierarchical structures have been synthesized by different methods. Over the past years, fabrication of hierarchical hollow nanostructures has attracted significant interest because of their widespread potential applications in catalysis, drug delivery, acoustic insulation, photonic crystals, and other areas. Until now, the general approach for preparation of hollow structures has involved the use of various removable or sacrificial templates, referred to as “hard”, such as monodispersed silica, polymer latex spheres and reducing metal nanoparticles, as well as “soft” ones, for example, emulsion droplets/ micelles and gas bubbles. Furthermore, lots of one-pot template-free methods for generating hollow inorganic microand nanostructures have been developed employing novel mechanisms, including the nanoscale corrosion-based insideout evacuation and Kirkendall effect. Recently, rhombododecahedral silver cages have been prepared by self-assembly coupled with the precursor crystal-templating approach. By treating the external morphologies of hollow structures, unique properties can be obtained. Thus, it is desirable to develop easy methods to control the morphologies of assembled systems with well-defined hierarchical structures. Herein, we report a simple controlled preparation of hierarchical hollow microspheres and microcubes of MnO2 nanosheets through self-assembly with an intermediate crystaltemplating process. As shown in Figure 1, the synthesis is performed by a three-step process. Particularly, discrete spherical and cubic hollow MnO2 nanostructures with controlled morphologies can be prepared by changing the morphologies of MnCO3 precursors, which can be simply obtained by adding the (NH4)2SO4 solution in the reaction system, and the

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Topics: Nanostructure (50%)

653 Citations


Journal ArticleDOI: 10.1002/ADMA.200800623
04 Aug 2008-Advanced Materials
Abstract: Hierarchically structured metal oxides have two or more levels of structure. Their nanometer-sized building blocks provide a high surface area, a high surface-to-bulk ratio, and surface functional groups that can interact with, e.g., heavy metal ions. Their overall micrometer-sized structure provides desirable mechanical properties, such as robustness, facile species transportation, easy recovery, and regeneration. In combination these features are suitable for the removal of heavy metal ions from water. Several general synthesis routes for the fabrication of metal oxides with various morphologies and hierarchical structures are discussed including soft and hard template-assisted routes. These routes are general, reliable, and environmentally friendly methods to prepare transition and rare earth metal oxides, including cobalt oxide, iron oxide, and ceria. As-prepared hierarchically structured metal oxides show excellent adsorption capacities for AsV and CrVI ions in water.

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Topics: Iron oxide (51%)

512 Citations


Journal ArticleDOI: 10.1021/IC051715B
Fangyi Cheng1, Jianzhi Zhao1, Wene Song1, Chunsheng Li1  +3 moreInstitutions (1)
Abstract: In this paper, MnO2 nanomaterials of different crystallographic types and crystal morphologies have been selectively synthesized via a facile hydrothermal route and electrochemically investigated as the cathode active materials of primary and rechargeable batteries. β-MnO2 nano/microstructures, including one-dimensional (1-D) nanowires, nanorods, and nanoneedles, as well as 2-D hexagramlike and dendritelike hierarchical forms, were obtained by simple hydrothermal decomposition of an Mn(NO3)2 solution under controlled reaction conditions. α- and γ-MnO2 nanowires and nanorods were also prepared on the basis of previous literature. The as-synthesized samples were characterized by instrumental analyses such as XRD, SEM, TEM, and HRTEM. Furthermore, the obtained 1-D α- and γ-MnO2 nanostructures were found to exhibit favorable discharge performance in both primary alkaline Zn−MnO2 cells and rechargeable Li−MnO2 cells, showing their potential applications in high-energy batteries.

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Topics: Nanorod (52%)

451 Citations


Journal ArticleDOI: 10.1016/J.CEJ.2013.09.034
Yingguo Zhao1, Yingguo Zhao2, Jiaxing Li2, Lanping Zhao  +5 moreInstitutions (2)
Abstract: Amidoxime-functionalized silica coated Fe3O4 (Fe3O4@SiO2-AO) was synthesized and carefully characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transformed infrared spectroscopy, and magnetic measurements. The prepared Fe3O4@SiO2-AO was applied to adsorb U(VI) from aqueous solutions and exhibited enhanced sorption capacity for U(VI) in comparison with raw silica coated Fe3O4 due to the strong chelation of amidoxime to U(VI). Effects of contact time, pH, ionic strength, interfering ions, U(VI) concentration, and temperature on the sorption of U(VI) on Fe3O4@SiO2-AO were investigated. The kinetic process of U(VI) sorption on Fe3O4@SiO2-AO reached equilibrium within 2 h. The sorption was strongly dependent on pH and independent of ionic strength, indicating that the sorption was mainly dominated by inner-sphere surface complexation. The sorption isotherm agreed well with the Langmuir model, having a maximum sorption capacity of 0.441 mmol g−1 at pH = 5.0 ± 0.1 and T = 298 K. The U(VI)-loaded Fe3O4@SiO2-AO could be readily separated from aqueous solutions by an external magnetic field and efficiently regenerated by 1 mol L−1 HCl with only slight decrease in U(VI) sorption capability. Findings of the present work suggest that Fe3O4@SiO2-AO is a potential and suitable candidate for the preconcentration and separation of U(VI) from seawater and contaminated wastewater.

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Topics: Sorption (66%), Adsorption (51%), Ionic strength (51%)

344 Citations