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Aqueous zinc-sulfur battery has garnered significant attention as a high-energy, low-cost, and safe energy storage system. However, the multielectron transfer kinetics of sulfur cathodes are relatively slow, presenting challenges such as limited sulfur utilization and lower discharge voltage, which significantly hinder their practical applications. In this study, we explored a comprehensive design approach for high-performance, long-cycle aqueous zinc-sulfur batteries. The simultaneous introduction of ZnI and Fe single atoms (Fe-SAs) as catalytically active agents decouples the redox reactions, effectively facilitating ZnS oxidation and S reduction separately. The application of an external magnetic field regulates the spin state of Fe-SAs, further enhancing their catalytic activity and electron transfer capability. Electrochemical tests demonstrate that the S@Fe-NC HS/ZnI cathode assembled under a magnetic field exhibits excellent rate performance, achieving an impressive specific capacity of 1399 mAh g at a high current density of 5 A g and good cycling stability over 300 cycles, representing the highest reported high-current discharge capacity to date. This study provides a comprehensive design framework for optimizing zinc-sulfur (Zn-S) battery performance and elucidates the influence of magnetic field-induced spin state modulation on catalytic behavior.
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http://dx.doi.org/10.1021/acsnano.5c05185 | DOI Listing |
Anal Sens
January 2025
Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390 United States.
At present, two competing hyperpolarization (HP) techniques, dissolution dynamic nuclear polarization (DNP) and parahydrogen (para-H) induced polarization (PHIP), can generate sufficiently high liquid state C signal enhancement for in vivo studies. PHIP utilizes the singlet spin state of para-H to create non-equilibrium spin populations. In hydrogenative PHIP, para-H is irreversibly added to unsaturated precursors, typically in the presence of a homogeneous catalyst.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
September 2025
Department of Materials Science and Engineering, University of California, Berkeley, California 94720, United States.
Density functional theory (DFT) calculations are employed to investigate the formation energies, charge redistribution, and binding energies of iron-oxygen divacancies in magnetite (FeO) and hematite (FeO). For magnetite, we focus on the low-temperature phase to explore variations with local environments. Building on previous DFT calculations of the variations in formation energies for oxygen vacancies with local charge and spin order in magnetite, we extend this analysis to include octahedral iron vacancies before analyzing the iron-oxygen divacancies.
View Article and Find Full Text PDFNatl Sci Rev
September 2025
Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials, Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China.
Covalent organic frameworks (COFs) have great potential as versatile platforms for proton conduction. However, the commonly applied 2D COFs that are easy to design and synthesize have only 1D channels for proton conduction, limiting the formation of continuous hydrogen bonds due to the anisotropy between their crystalline grains. Herein, we report a strategy to construct 3D channels in 2D COFs by using rotaxane structures and eliminate the strong interlayer π-π interactions, facilitating the formation of smooth 3D proton-transfer pathways during guest doping.
View Article and Find Full Text PDFDalton Trans
September 2025
Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry, Russian Academy of, Sciences, Chernogolovka, Moscow region 142432, Russia.
Neutral iron(III) and iron(II) complexes based on the pyruvic acid thiosemicarbazone (Hthpy) ligand [Fe(Hthpy)(thpy)] (1) and [Fe(Hthpy)] (2) were synthesized, and deeper insights into magneto-structural correlation were gained by FT-IR spectroscopy, single crystal X-ray crystallography, dc magnetic characterization, Fe Mössbauer spectroscopy, and DFT calculations. The X-ray structures of complex 1 were established for the HS ( = 5/2) state at 295 K and the LS ( = 1/2) state at 150 K. The crystal packing of 1 at these temperatures corresponds to the triclinic 1̄ symmetry and contains pairs of [Fe(Hthpy)(thpy)] complexes interconnected by a shortened S⋯S contact.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2025
Key Laboratory of Organic Synthesis of Jiangsu Province & State Key Laboratory of Bioinspired Interfacial Materials Science, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, P.R. China.
Reaction of LZnI [L = BuC(N-DIPP), DIPP = 2,6-Pr-CH] with KC in the presence of cyclic (alkyl)(amino)carbene (cAAC) affords a stable radical complex [LZn(cAAC)] (3). Single-crystal structural analysis of 3 shows a short Zn─C bond and concomitant elongation of C─N bond within the cAAC ligand, indicating a significant π-backbonding from the metal to the cAAC ligand. EPR spectroscopy and DFT calculations reveal that the spin density is mainly localized on the carbenic carbon atom, with a small portion on the zinc center.
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