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Search Results (167)

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Keywords = cobalt(III)

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36 pages, 2136 KB  
Review
Valorization of Agro-Industrial Lignin as a Functional Polymer for Sustainable Wastewater Treatment
by Elena Ungureanu, Bogdan-Marian Tofanica, Eugen Ulea, Ovidiu C. Ungureanu, Maria E. Fortună, Răzvan Rotaru, Irina Volf and Valentin I. Popa
Polymers 2025, 17(16), 2263; https://doi.org/10.3390/polym17162263 - 21 Aug 2025
Viewed by 1165
Abstract
The rational design of functional and sustainable polymers is central to addressing global environmental challenges. In this context, unmodified lignin derived from Sarkanda grass (Tripidium bengalense), an abundant agro-industrial lignocellulosic byproduct, was systematically investigated as a natural polymeric adsorbent for the [...] Read more.
The rational design of functional and sustainable polymers is central to addressing global environmental challenges. In this context, unmodified lignin derived from Sarkanda grass (Tripidium bengalense), an abundant agro-industrial lignocellulosic byproduct, was systematically investigated as a natural polymeric adsorbent for the remediation of aqueous media contaminated with heavy metals. The study evaluates lignin’s behavior toward nine metal(loid) ions: arsenic, cadmium, chromium, cobalt, copper, iron, nickel, lead, and zinc. Adsorption performance was systematically investigated under static batch conditions, optimizing key parameters, with equilibrium and kinetic data modeled using established isotherms and rate equations. Surface characterization and seed germination bioassays provided supporting evidence. Unmodified Sarkanda grass lignin demonstrated effective adsorption, exhibiting a clear preference for Cu(II) followed by other divalent cations, with lower capacities for As(III) and Cr(VI). Adsorption kinetics consistently followed a pseudo-second-order model, indicating chemisorption as the dominant mechanism. Thermodynamic studies revealed spontaneous and endothermic processes. Bioassays confirmed significant reduction in aqueous toxicity and strong metal sequestration. This work positions unmodified Sarkanda grass lignin as a bio-based, low-cost polymer platform for emerging water treatment technologies, contributing to circular bioeconomy goals and highlighting the potential of natural polymers in sustainable materials design. Full article
(This article belongs to the Special Issue Designing Polymers for Emerging Applications)
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38 pages, 5853 KB  
Article
Development of Technology for Processing Pyrite–Cobalt Concentrates to Obtain Pigments of the Composition Fe2O3 and Fe3O4
by Tatyana Chepushtanova, Aliya Altmyshbayeva, Yerik Merkibayev, Kulzira Mamyrbayeva, Zhanat Yespenova and Brajendra Mishra
Metals 2025, 15(8), 886; https://doi.org/10.3390/met15080886 - 7 Aug 2025
Cited by 1 | Viewed by 483
Abstract
This paper presents the results of a study on the development of a processing technology for pyrite–cobalt concentrates to obtain iron oxide pigments (Fe2O3 and Fe3O4) via high-temperature hydrolysis. It was found that, in a single [...] Read more.
This paper presents the results of a study on the development of a processing technology for pyrite–cobalt concentrates to obtain iron oxide pigments (Fe2O3 and Fe3O4) via high-temperature hydrolysis. It was found that, in a single operation, the concentrate can be effectively purified from lead, zinc, and copper, yielding an iron–nickel–cobalt product suitable for further processing by standard technologies, such as smelting into ferronickel. The scientific originality of research concludes in a mechanism of stepwise selective chloride volatilization, which was established as follows: stage I (500–650 °C)—removal of lead; stage II (700–750 °C)—chlorination of copper and iron; stage III (850–900 °C)—volatilization of nickel and cobalt. Microprobe analysis of the powders obtained from high-temperature hydrolysis of FeCl2·4H2O and FeCl3·6H2O revealed the resulting Fe3O4 and Fe2O3 powders with particle sizes 50 μm and 100 μm. A visual color palette was created, corresponding to different Fe3O4/Fe2O3 ratios in the pigment composition—ranging from black (magnetite) to red (hematite)—and potential application areas. For the first time, the new technological scheme was proposed of pigments Fe2O3 and Fe3O4 production from pyrite–cobalt concentrates via combination of oxidized roasting with subsequent chlorination and high-temperature hydrolysis of the products. Full article
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16 pages, 2520 KB  
Article
Infrared Spectroscopic Determination of Strongly Bound Cyanides in Water
by Rihab Masmoudi and Carl P. Tripp
Spectrosc. J. 2025, 3(3), 21; https://doi.org/10.3390/spectroscj3030021 - 17 Jul 2025
Viewed by 465
Abstract
Cyanide species pose an environmental concern as they inhibit important biological processes in humans and aquatic systems. There is more focus on free-CN and weak acid dissociables cyanide as hazardous species compared to strong acid dissociables due to their higher reactivity and toxicity. [...] Read more.
Cyanide species pose an environmental concern as they inhibit important biological processes in humans and aquatic systems. There is more focus on free-CN and weak acid dissociables cyanide as hazardous species compared to strong acid dissociables due to their higher reactivity and toxicity. However, the strong acid dissociables cyanide also poses health concerns as it liberates free-CN under ultraviolet irradiation or when present in acidic solutions. Detection of strongly acid dissociables cyanide typically requires its digestion in acidic solutions and measurement of the gaseous HCN produced. A simple infrared spectroscopic method is described here to speciate and quantify three strong acid dissociables cyanide: [Fe(CN)6]3−, [Co(CN)6]3−, and [Au(CN)2]. The strategy involves precipitating the strongly acid dissociables cyanide using cetyltrimethylethylammonium bromide, capturing the precipitate on a polyethylene membrane, and quantifying the individual strongly acid dissociables cyanide from the IR spectrum recorded in transmission mode through the membrane. Controlling the particle diameter to be in the range of 0.2–2 µm is important. Particles less than 0.2 µm pass through the membrane, whereas particles larger than about 2 µm lead to nonlinearity in quantification. The average %recoveries for [Fe(CN)6]3−, [Co(CN)6]3−, and [Au(CN)2] were 100% (%RSD = 7), 91% (%RSD = 7), and 101% (%RSD = 8), respectively. The detection limit for [Fe(CN)6]3− and [Co(CN)6]3− were both 20 ppb CN, whereas [Au(CN)2] was 100 ppb CN. The detection range was 20–750 ppb CN for [Fe(CN)6]3− and [Co(CN)6]3− and 100–750 ppb CN for [Au(CN)2] with a linear regression of R2 = 0.999–1.000. Full article
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19 pages, 7336 KB  
Article
Impacts of Structural Impurities and Solution pH on Hausmannite Transformation to Birnessite: Environmental Implications for Metal Solubility and Sequestration
by Boyoung Song, Mohammad M. Rashid, Evert J. Elzinga and Bojeong Kim
Minerals 2025, 15(7), 697; https://doi.org/10.3390/min15070697 - 29 Jun 2025
Viewed by 844
Abstract
Spinel-structured hausmannite (Mn(II)Mn(III)2O4) is a vital intermediate in Mn mineralogy and a key player in redox chemistry in the environment. Its transformation into other Mn oxides is a critical factor in controlling its environmental occurrence and reactivity. Yet structural [...] Read more.
Spinel-structured hausmannite (Mn(II)Mn(III)2O4) is a vital intermediate in Mn mineralogy and a key player in redox chemistry in the environment. Its transformation into other Mn oxides is a critical factor in controlling its environmental occurrence and reactivity. Yet structural impurities and solution pH, as well as the fate of impurities during transformation, which influence hausmannite transformation processes and products, remain largely unknown. In the present work, we address this knowledge gap by investigating pristine and metal-substituted hausmannite, specifically nickel (Ni) or cobalt (Co), equilibrated at two time periods (8 h and 30 days) and three different pH levels (4, 5, and 7). Solution chemistry data revealed that both the equilibration period and pH had a significant impact on hausmannite dissolution rates and the concomitant repartitioning of Ni or Co. Hausmannite with Ni or Co substitution exhibited lower dissolution rates than pristine mineral under acidic conditions. Mineralogy and crystal chemistry data indicated that hausmannite was the major host phase after 30-day equilibration, followed by minor transformed products, including birnessite and manganite. Although minor, birnessite became more abundant than manganite at low pHs. Analytical high-resolution transmission electron microscopy (HRTEM) analyses revealed a poorly crystalline, nano-scaled MnO2 formed from hausmannite and the majority of metal impurities remaining in the host hausmannite. Yet Co was associated with both hausmannite and the newly formed birnessite, whereas Ni was only found with hausmannite, indicating the strong sequestration of Co by Mn(II/III) and Mn(IV) mineral phases. This study highlights the significant impacts of metal impurities and pH on the stability of hausmannite and its transformation into birnessite, as well as the control of Mn-oxide minerals on the solubility and sequestration of transition metals in the environment. Full article
(This article belongs to the Special Issue Characterization of Geological Material at Nano- and Micro-scales)
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20 pages, 2995 KB  
Article
Genotoxic Effects of Chromium(III) and Cobalt(II) and Their Mixtures on the Selected Cell Lines
by Katarzyna Czarnek, Małgorzata Tatarczak-Michalewska, Eliza Blicharska, Andrzej K. Siwicki and Ryszard Maciejewski
Int. J. Mol. Sci. 2025, 26(11), 5056; https://doi.org/10.3390/ijms26115056 - 24 May 2025
Viewed by 2790
Abstract
Cr(III) and Co(II) can be potentially toxic to cells and induce a number of morphological and biochemical changes. These metals are widely used in many industries and can cause environmental pollution. They are the components of dietary supplements, vitamin and mineral products, and [...] Read more.
Cr(III) and Co(II) can be potentially toxic to cells and induce a number of morphological and biochemical changes. These metals are widely used in many industries and can cause environmental pollution. They are the components of dietary supplements, vitamin and mineral products, and energy drinks. Moreover, these metals are used in dentistry and orthopedics as components of implants. Data about the mechanism of genotoxic effects of Cr(III) and Co(II) are still incomplete. The aim of this study was to analyze the genotoxic effects of chromium(III) and cobalt(II) and their mixtures on two cell lines: mouse embryo fibroblast cell line BALB/3T3 and human hepatocellular carcinoma cell line G2 (HepG2). The BALB/3T3 and HepG2 cell lines were exposed to chromium chloride and cobalt chloride at concentrations ranging from 100 to 1400 µM. The genotoxicity assays used were the comet and micronucleus assays. On the basis of the results obtained from the first stage of the research, the concentrations of elements were selected in order to determine the interactions between them. The tested cell lines were treated with mixtures of the following compounds: chromium chloride at the concentration of 200 μM and cobalt chloride at the concentration of 1000 μM or chromium chloride at the concentration of 1000 μM and cobalt chloride at the concentration of 200 μM in the genotoxicity assays. This study shows that both cobalt(II) and chromium(III) cause genotoxic effects in the BALB/3T3 and HepG2 cell lines. A statistically significant increase in the percentage of comets was observed with increasing concentrations of Co(II) and Cr(III) compared to the control. A statistically significant induction of chromosomal aberrations was also observed in the micronucleus test. Moreover, chromium(III) at a concentration of 200 µM had a protective effect against the toxic concentration of cobalt(II) at a concentration of 1000 µM. The toxic effect of cobalt chloride and chromium chloride was confirmed in this study. Further research is needed on the genotoxic effects of cobalt(II) and chromium(III), especially due to the growing popularity of dietary supplements containing compounds of these metals and doubts as to the safety of their use. Full article
(This article belongs to the Special Issue Molecular Mechanism in DNA Replication and Repair)
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14 pages, 1458 KB  
Article
Synthesis, Reductive Reactivity and Anticancer Activity of Cobalt(III)– and Manganese(III)–Salen Complexes
by Amy Kanina, Haiyu Mei, Cheska Palma, Michelle C. Neary, Shu-Yuan Cheng and Guoqi Zhang
Chemistry 2025, 7(3), 85; https://doi.org/10.3390/chemistry7030085 - 23 May 2025
Cited by 1 | Viewed by 1054
Abstract
Mn(III)– and Co(III)–salen complexes (Mn-1 and Co-2) have been synthesized by a simple one-pot procedure through oxidation of Mn(II) and Co(II) precursors in air. X-ray structural analysis reveals that both complexes adopt similar coordination modes, including a typical square planar metal/salen [...] Read more.
Mn(III)– and Co(III)–salen complexes (Mn-1 and Co-2) have been synthesized by a simple one-pot procedure through oxidation of Mn(II) and Co(II) precursors in air. X-ray structural analysis reveals that both complexes adopt similar coordination modes, including a typical square planar metal/salen coordination sphere, which is further occupied by two axial ligands, i.e., an acetate anion and a water molecule. Despite their structural similarity, they are not isomorphous given their distinct cell parameters. In the solid-state structures, both complexes exist as hydrogen-bonded dimers through hydrogen bonding interactions between the axially coordinating water molecules and outer O4 cavity from another molecule of the complex. The reductive activity of both complexes has been explored. While the reaction of Mn-1 with potassium triethylborohydride was unsuccessful, leading to a complicated mixture, the use of Co-2 furnished the formation of a novel product (CoK-3) that was isolated as red crystals in reasonable yield. CoK-3 was characterized as a heterometallic dimer involving the coordination of a K+ ion within the O4 cavity of a semi-hydrogenated salen/cobalt complex while the cobalt center has been reduced from Co(III) to Co(II). In addition, an attempt at reducing Co-2 with pinacolborane resulted in the isolation of crystals of Co-4, whose structure was determined as a simple square planar CoII–salen complex. Finally, three complexes (Mn-1, Co-2 and CoK-3) have been investigated for their cytotoxic activities against two human breast cancer cell lines (MCF-7 and MDA-MB 468) and a normal breast epitheliel cell line (MCF-10A), with cisplatin used as a reference in order to discover potential drug candidates that may compete with cisplatin. The results reveal that Co-2 can be a promising drug candidate, specifically for the MCF-7 cancer cells, with minimal damage to healthy cells. Full article
(This article belongs to the Section Inorganic and Solid State Chemistry)
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21 pages, 3742 KB  
Article
Mixed 3d-3d’-Metal Complexes: A Dicobalt(III)Iron(III) Coordination Cluster Based on Pyridine-2-Amidoxime
by Sotiris G. Skiadas, Christina D. Polyzou, Zoi G. Lada, Rodolphe Clérac, Yiannis Sanakis, Pierre Dechambenoit and Spyros P. Perlepes
Inorganics 2025, 13(5), 171; https://doi.org/10.3390/inorganics13050171 - 17 May 2025
Viewed by 1504
Abstract
In the present work, we describe the use of the potentially tridentate ligand pyridine-2-amidoxime (NH2paoH) in Fe-Co chemistry. The 1:1:3 FeIII(NO3)3·9H2O/CoII(ClO4)2·6H2O/NH2paoH reaction mixture [...] Read more.
In the present work, we describe the use of the potentially tridentate ligand pyridine-2-amidoxime (NH2paoH) in Fe-Co chemistry. The 1:1:3 FeIII(NO3)3·9H2O/CoII(ClO4)2·6H2O/NH2paoH reaction mixture in MeOH gave complex [CoIII2FeIII(NH2pao)6](ClO4)2(NO3) (1) in ca. 55% yield, the cobalt(II) being oxidized to cobalt(III) under the aerobic conditions. The same complex was isolated using cobalt(II) and iron(II) sources, the oxidation now taking place at both metal sites. The structure of 1 contains two structurally similar, crystallographically independent cations [CoIII2FeIII(NH2pao)6]3+ which are strictly linear by symmetry. The central high-spin FeIII ion is connected to each of the terminal low-spin CoIII ions through the oximato groups of three 2.1110 (Harris notation) NH2pao ligands, in such a way that the six O atoms are bonded to the octahedral FeIII center ({FeIIIO6} coordination sphere). Each terminal octahedral CoIII ions is bonded to six N atoms (three oximato, three 2-pyridyl) from three NH2pao groups ({CoIIIN6} coordination sphere). The IR and Raman spectra of the complex are discussed in terms of the coordination mode of the organic ligand, and the non-coordinating nature of the inorganic ClO4 and NO3 counterions. The UV/VIS spectrum of the complex in EtOH shows the two spin-allowed d-d transitions of the low-spin 3d6 cobalt(III) and a charge-transfer NH2pao → FeIII band. The δ and ΔΕQ 57Fe-Mössbauer parameter of 1 at 80 K show the presence of an isolated high-spin FeIII center. Variable-temperature (1.8 K–300 K) and variable-field (0–7 T) magnetic studies confirm the isolated character of FeIII. A critical discussion of the importance of NH2paoH and its anionic forms (NH2pao, NHpao2−) in homo- and heterometallic chemistry is also attempted. Full article
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18 pages, 2959 KB  
Article
Evaluating Performance of Metal-Organic Complexes as Electrodes in Hydrogen Peroxide Fuel Cells
by Faraz Alderson, Raveen Appuhamy and Stephen Andrew Gadsden
Energies 2025, 18(10), 2598; https://doi.org/10.3390/en18102598 - 17 May 2025
Viewed by 486
Abstract
With increasing energy demands, fuel cells are a popular avenue for portability and low waste emissions. Hydrogen fuel cells are popular due to their potential output power and clean waste. However, due to storage and transport concerns, hydrogen peroxide fuel cells are a [...] Read more.
With increasing energy demands, fuel cells are a popular avenue for portability and low waste emissions. Hydrogen fuel cells are popular due to their potential output power and clean waste. However, due to storage and transport concerns, hydrogen peroxide fuel cells are a promising alternative. Although they have a lower output potential compared to hydrogen fuel cells, peroxide can act as both the oxidizing and reducing agent, simplifying the structure of the cell. In addition to reducing the complexity, hydrogen peroxide is stable in liquid form and can be stored in less demanding methods. This paper investigates chelated metals as electrode material for hydrogen peroxide fuel cells. Chelated metal complexes are ring-like structures that form from binding organic or inorganic compounds with metal ions. They are used in medical imaging, water treatment, and as catalysts for reactions. Copper(II) phthalocyanine, phthalocyanine green, poly(copper phthalocyanine), bis(ethylenediamine)copper(II) hydroxide, iron(III) ferrocyanine, graphene oxide decorated with Fe3O4, zinc phthalocyanine, magnesium phthalocyanine, manganese(II) phthalocyanine, cobalt(II) phthalocyanine are investigated as electrode materials for peroxide fuel cells. In this study, the performance of these materials is evaluated using cyclic voltammetry. The voltammograms are compared, as well as observations are made during the materials’ use to measure their effectiveness as electrode material. There has been limited research comparing the use of these chelated metals in the context of hydrogen peroxide fuel cells. Through this research, the goal is to further the viability of hydrogen peroxide fuel cells. Poly(copper phthalocyanine) and graphene oxide doped with iron oxides had strong redox catalytic activity for use in acidic peroxide single-compartment fuel cells, where the poly(copper phthalocyanine) electrode compound generated the highest peak power density of 7.92 mW/cm2 and cell output potential of 0.634 V. Full article
(This article belongs to the Section D: Energy Storage and Application)
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17 pages, 3550 KB  
Article
Advanced Degradation of Aniline in Secondary Effluent from a Chemical Industry Park by Cobalt Ferrite/Peracetic Acid System
by Jinxiang Gao, Peishan Yang, Mingxin Zhu, Hua Zhou and Shunlong Pan
Catalysts 2025, 15(5), 410; https://doi.org/10.3390/catal15050410 - 23 Apr 2025
Viewed by 638
Abstract
The residual emerging pollutants in secondary effluent from a chemical industry park contain potential risks for natural waters. Herein, the cobalt ferrite/peracetic acid system was employed to destroy aniline, a typical emerging pollutant, with a reaction rate of 0.0147 min−1 at pH [...] Read more.
The residual emerging pollutants in secondary effluent from a chemical industry park contain potential risks for natural waters. Herein, the cobalt ferrite/peracetic acid system was employed to destroy aniline, a typical emerging pollutant, with a reaction rate of 0.0147 min−1 at pH 7.0. Singlet oxygen (1O2) served as the predominant reactive species for aniline degradation, with superoxide radicals (O2) and organic radicals (R-O) acting in secondary roles. The valence transition between Co(II) and Co(III) on the CoFe2O4 surface played a determining role in the reaction progression. The presence of anions and humic acids with low concentrations had minimal impact on aniline removal. Additionally, the CoFe2O4 catalyst demonstrated excellent recyclability, maintaining a pollutant removal rate above 93% over five consecutive cycles. Lastly, the CoFe2O4/PAA system demonstrates effective treatment of typical pollutants, including phenolic compounds, pesticides, antibiotics, and dyes, achieving removal rates of 77.48% to 99.99%. Furthermore, it significantly enhances water quality in the treatment of actual secondary effluent, offering a novel theoretical foundation and practical insights for applying this catalytic system in wastewater treatment. Full article
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51 pages, 23276 KB  
Article
Structure–Function Analysis of the Self-Sufficient CYP102 Family Provides New Insights into Their Biochemistry
by Tiara Padayachee, David C. Lamb, David R. Nelson and Khajamohiddin Syed
Int. J. Mol. Sci. 2025, 26(5), 2161; https://doi.org/10.3390/ijms26052161 - 28 Feb 2025
Cited by 2 | Viewed by 1337
Abstract
Cytochromes P450 are a superfamily of heme-containing monooxygenases involved in a variety of oxidative metabolic reactions, primarily catalyzing the insertion of an oxygen atom into a C-H bond. CYP102 represents the first example of a bacterial P450 that can be classified as a [...] Read more.
Cytochromes P450 are a superfamily of heme-containing monooxygenases involved in a variety of oxidative metabolic reactions, primarily catalyzing the insertion of an oxygen atom into a C-H bond. CYP102 represents the first example of a bacterial P450 that can be classified as a type II (eukaryotic-like) P450 and functions as a catalytically self-sufficient enzyme. These unique features have made CYP102 an attractive system for studying P450 structure and function. However, an overall picture of the specific amino acid residues that are crucial to the functioning of CYP102 and the effect of mutations on the P450 structure and catalysis is yet to be reported. Such an approach will aid protein engineering approaches used to improve this enzyme. To address this research knowledge gap, we have investigated 105 CYP102 crystal structures in this study. We demonstrate that the CYP102 active site is highly dynamic and flexible. Amino acid residues that play critical roles in substrate binding, orientation, and anchoring were identified. Mutational studies highlighted the roles of amino acids and provided possible bioengineering improvement strategies for CYP102. Decoy molecules are a promising agent for deceiving CYP102 and permitting non-native substrates into the active site. Ru(II)-diimine photosensitizers and zinc/cobalt (III) sepulchrate (Co(III)Sep) could be used as alternative electron sources. The present study serves as a reference for understanding the structure–functional analysis of CYP102 family members precisely and of P450 enzymes in general. Significantly, this work contributes to the effort to develop an improved CYP102 enzyme, thereby advancing the field of P450 research and potentially leading to new industrial applications. Full article
(This article belongs to the Section Biochemistry)
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19 pages, 12229 KB  
Article
Green Synthesis of Cobalt–Zinc Ferrites and Their Activity in Dye Elimination via Adsorption and Catalytic Wet Peroxide Oxidation
by Mariia Liaskovska, Tetiana Tatarchuk and Volodymyr Kotsyubynsky
Metals 2025, 15(1), 44; https://doi.org/10.3390/met15010044 - 5 Jan 2025
Cited by 6 | Viewed by 1471
Abstract
Zinc-substituted cobalt ferrites were obtained by a green method using a black grape extract as a reductant and fuel. XRD analysis confirmed the spinel structure of the synthesized ferrites. An increase in the lattice constant is explained by increased Zn content. SEM analysis [...] Read more.
Zinc-substituted cobalt ferrites were obtained by a green method using a black grape extract as a reductant and fuel. XRD analysis confirmed the spinel structure of the synthesized ferrites. An increase in the lattice constant is explained by increased Zn content. SEM analysis confirmed changes in surface morphology, whereas FTIR spectra demonstrated the presence of organic species in the samples, which originated from grape extract. The content of Co(II) ions in octahedral sites as a function of the ratio between Fe(III) ions in A- and B-sites was calculated from Mössbauer data. pHPZC rose from 7.85 to 8.13 with an increase in zinc content, indicating a positive charge of the adsorbent surface at natural pH. The adsorption–catalytic properties of the spinel samples were investigated in terms of Congo Red (CR) dye removal. The mechanism of CR adsorption on the ferrite surface includes electrostatic and donor–acceptor interactions with the adsorbent surface. Furthermore, the sample with x(Zn) = 0.4 exhibited the highest degradation rate constant k = 0.102 min−1 in the peroxide oxidation of CR, whereas the sample with x(Zn) = 1.0 exhibited the highest adsorption capacity. The electron transfer between ferrite samples and hydrogen peroxide was evidenced using electrochemical tests. The green-synthesized Co-Zn ferrites demonstrate a big potential as adsorbents/catalysts for water treatment. Full article
(This article belongs to the Section Powder Metallurgy)
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17 pages, 1541 KB  
Article
Reconsidering Waterfront Regeneration and Cruise Tourism in Hamburg, Germany
by Carlos J. L. Balsas
Sustainability 2025, 17(1), 67; https://doi.org/10.3390/su17010067 - 26 Dec 2024
Viewed by 1985
Abstract
Written accounts of cultural festivals often deal with the various activities that comprise those types of events. There is a paucity of analyses that discuss how festivals encourage the status quo of consumption practices, while conjuring their hidden costs on society. This paper [...] Read more.
Written accounts of cultural festivals often deal with the various activities that comprise those types of events. There is a paucity of analyses that discuss how festivals encourage the status quo of consumption practices, while conjuring their hidden costs on society. This paper analyses how the Hamburg Cruise Days Festival attempted to perpetuate the status quo of the cruising industry. The research answers the following question: What would it take to help change the current “cobalt” color promoted by the organizers of the Hamburg’s Waterfront Cruise Days Festival to a “True Blue”, a symbol of the cleanest sky and harbor waters in Germany, and the best example of sustainable Green and Blue Infrastructure in Europe? The research methods comprised in loco fieldwork participant observation in the tradition of participatory action research. It is argued that, from a governance perspective, festival organizers ought to be required to disclaim, in the fashion of “truth in advertising”, the ecological impacts and sponsors’ progress toward reaching existing environmental standards to eradicate costly social and environmental injustices. Said practice will increase our individual and collective awareness of the invaluable richness of the world’s land- and water-based environment before it is irreplaceably exhausted. The article suggests extending events’ emphasis on sustainable tourism to also encompass three additional measures: (i) the socio-ecological performance of the cruise (and shipping) industry; (ii) in the fashion of a Solomonic approach to justice; and (iii) within a formalized Porto of Call Sister Cities Network. Full article
(This article belongs to the Section Tourism, Culture, and Heritage)
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13 pages, 2724 KB  
Article
Enhanced Electrochemical Performance of Carbon-Composited Co3O4 Microspheres as Anode Materials for Lithium-Ion Batteries
by Achmad Yanuar Maulana and Jongsik Kim
Materials 2024, 17(23), 5702; https://doi.org/10.3390/ma17235702 - 21 Nov 2024
Viewed by 1347
Abstract
Cobalt (II, III) oxide (Co3O4) has recently gained attention as an alternative anode material to commercial graphite in lithium-ion batteries (LIBs) due to its superior safety and large theoretical capacity of about 890 mAh g−1. However, its [...] Read more.
Cobalt (II, III) oxide (Co3O4) has recently gained attention as an alternative anode material to commercial graphite in lithium-ion batteries (LIBs) due to its superior safety and large theoretical capacity of about 890 mAh g−1. However, its practical application is limited by poor electrical conductivity and rapid capacity degradation because of significant volume increases and structural strain during repeated lithiation/delithiation cycles. To address these issues, this work presents a novel approach to synthesizing carbon-composited Co3O4 microspheres (Co3O4@C), using abietic acid (AA) as a carbon source to increase conductivity and structural stability. The resulting Co3O4@C anodes show an impressive discharge capacity of 1557.4 mAh g−1 after 200 cycling processes at a current density of 0.1 C, representing a significant improvement over bare Co3O4. This study demonstrates the potential of carbon-compositing as a strategy to mitigate the limitations of Co3O4 and extend its cyclability, making it a viable candidate for next-generation LIB anodes. Full article
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23 pages, 581 KB  
Review
The Role of Nutrition in the Pathogenesis and Treatment of Autoimmune Bullous Diseases—A Narrative Review
by Aleksandra Anna Kajdas, Agnieszka Żebrowska, Anna Zalewska-Janowska and Aneta Czerwonogrodzka-Senczyna
Nutrients 2024, 16(22), 3961; https://doi.org/10.3390/nu16223961 - 20 Nov 2024
Cited by 1 | Viewed by 4072
Abstract
Autoimmune bullous diseases (AIBDs) are a group of conditions marked by the formation of blisters and erosions on the skin and mucous membranes. It occurs in all age groups, slightly more often affecting women. Several factors may be linked to the development of [...] Read more.
Autoimmune bullous diseases (AIBDs) are a group of conditions marked by the formation of blisters and erosions on the skin and mucous membranes. It occurs in all age groups, slightly more often affecting women. Several factors may be linked to the development of AIBDs, with nutrition being one of them. The literature mentions various food products and food ingredients acting as disease modifiers. Given the complex relationship between bullous diseases and nutrition, the current literature on AIBDs has been reviewed, with an emphasis on the influence of dietary modifications, various diets, and the nutritional consequences of these conditions. This review summarizes the role of nutrition in the pathogenesis and treatment of the following AIBDs: (i) pemphigus, (ii) bullous pemphigoid and mucous membrane pemphigoid, (iii) dermatitis herpetiformis, and (iv) epidermolysis bullosa acquisita. Several nutrients and dietary factors have been studied for their potential roles in triggering or exacerbating AIBDs. The key nutrients and their potential impacts include thiols and bulb vegetables (Allium), phenols, tannic acid, tannins, phycocyanin, isothiocyanates, all trans-retinoic acids, cinnamic acid, and walnut antigens. Many patients with ABIDs may require supplementation, particularly of vitamin D and B3, calcium, potassium, zinc, selenium, and cobalt. In addition, various diets play an important role. A soft diet is recommended for individuals with issues in the oral cavity and/or esophagus, particularly for those who experience difficulties with biting or swallowing. This approach is commonly used in managing pemphigus. A high-protein, high-calcium diet, DASH (Dietary Approaches to Stop Hypertension), and the Mediterranean diet are utilized during long-term glucocorticoid therapy. However, in dermatitis herpetiformis it is advisable to follow a gluten-free diet and eliminate iodine from the diet. When it comes to herbal supplements, Algae (Spirulina platensis), Echinacea, and St. John’s wort (Hyperitum perforatum) enhance the ABIDs, while Cassia fistula may be recommended in the treatment of erosions in pemphigus vulgaris. Fast foods enhance the development of ABIDs. However, the pathomechanism is not yet fully understood. Future researchers should more precisely define the relationships between nutrients and nutrition and blistering diseases by also looking at, i.e., genetic predispositions, microbiome differences, or exposure to stress. Full article
(This article belongs to the Special Issue Relationships between Dietary Factors and Inflammatory Skin Diseases)
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Proceeding Paper
Microwave-Assisted Green Synthesis of Binary/Ternary ZnxCo1−xFe2O4 (x = 0, 0.5, 1) Nanoparticles
by Sanaz Chamani and Masoumeh Khatamian
Chem. Proc. 2024, 16(1), 29; https://doi.org/10.3390/ecsoc-28-20248 - 15 Nov 2024
Viewed by 635
Abstract
In this study, magnetic binary/ternary ZnxCo1−xFe2O4 (x = 0, 0.5, 1) nanoparticles were synthesized using a straightforward one-step microwave technique. To produce the ZnxCo1−xFe2O4 nanoparticles, iron [...] Read more.
In this study, magnetic binary/ternary ZnxCo1−xFe2O4 (x = 0, 0.5, 1) nanoparticles were synthesized using a straightforward one-step microwave technique. To produce the ZnxCo1−xFe2O4 nanoparticles, iron (III) nitrate nonahydrate, zinc nitrate hexahydrate, and cobalt nitrate hexahydrate were used as metal sources, with urea used as the fuel and ammonium nitrate as the oxidizer. These materials were combined in an alumina crucible covered by a CuO jacket to absorb microwave energy and facilitate calcination. The thermal treatment involved placing the alumina crucible in a domestic microwave oven at 450 W for 30 min. The key strengths of this experimental strategy include its simplicity, cost-effectiveness, and rapidity, aligning with green chemistry principles. The synthesized nanoparticles were characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, a vibrating sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET) analysis. XRD analysis confirmed the presence of the pure ferrite nanocrystalline phase. Scanning electron microscopy (SEM), employed with energy-dispersive X-ray spectroscopy (EDS), was used to study the surface morphology and analyze the elemental composition. The SEM analysis revealed that the synthesized magnetic nanoparticles had particle sizes ranging from 30 to 50 nm. Furthermore, we explored the potential use of these magnetic nanoparticles as photocatalysts for degrading organic pollutants such as methylene blue in aqueous solutions. Full article
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