Manganese (Mn) oxides are among the strongest mineral oxidants in the environment and impose significant influence on mobility and bioavailability of redox-active substances, such as arsenic, chromium, and pharmaceutical products, through oxidation processes. Oxidizing potentials of Mn oxides are determined by Mn valence states (2+, 3+, 4+). In this study, the effects of beam damage during electron energy-loss spectroscopy (EELS) in the transmission electron microscope have been investigated to determine the "safe dose" of electrons. Time series analyses determined the safe dose fluence (electrons/nm(2)) for todorokite (10(6) e/nm(2)), acid birnessite (10(5)), triclinic birnessite (10(4)), randomly stacked birnessite (10(3)), and δ-MnO(2) (<10(3)) at 200 kV. The results show that meaningful estimates of the mean Mn valence can be acquired by EELS if proper care is taken.
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http://dx.doi.org/10.1021/es203516h | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Nankai University, Department of Chemistry, Weijin road, 300071, Tianjin, CHINA.
Localized surface plasmon resonance (LSPR) metals exhibit remarkable light-absorbing property and unique catalytic activity, attracting significant attention in photocatalysts recently. However, the practical application of plasmonic nanometal is hindered by challenge of energetic electrons extraction and low selectivity. The energetic carriers generated in nanometal under illumination have extremely short lifetimes, leading to rapid energy loss.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India.
Heterogeneous catalysts have emerged as a potential key for closing the carbon cycle by converting carbon dioxide (CO) into value-added chemicals. In this work, we report a highly active and stable ceria (CeO)-based electronically tuned trimetallic catalyst for CO to CO conversion. A unique distribution of electron density between the defective ceria support and the trimetallic nanoparticles (of Ni, Cu, Zn) was established by creating the strong metal support interaction (SMSI) between them.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Conjugated polymer donors have always been one of the important components of organic solar cells (OSCs), particularly those featuring simple synthetic routes, proper energy levels, and appropriate aggregation behavior. In this work, we employed a nonfused electron-deficient building block, dicyanobithiophene (2CT), for constructing high-performance donors. Combining this with side-chain engineering, two novel halogen-free polymer donors, PB2CT-BO and PB2CT-HD, were reported.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
A bimetallic organic framework (CuNi-MOF) was synthesized as a corrosion inhibitor using the solvothermal method. The effectiveness of the inhibitor in corrosion prevention of AISI 304 and 316 in 1N hydrochloric acid solution at room temperature was evaluated using weight loss measurements, electrochemical methods, and surface characterization techniques. The formation of CuNi-MOF protective layer on the stainless-steel surface was confirmed through Field Emission Scanning Electron Microscopes (FESEM), Energy Dispersive Spectroscopy (EDS), and X-Ray Diffraction (XRD) analysis.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Nuclear, Plasma, and Radiological Engineering, The Grainger College of Engineering, University of Illinois Urbana-Champaign, Champaign, IL, USA.
Doped semiconductors can exhibit metallic-like properties ranging from superconductivity to tunable localized surface plasmon resonances. Diamond is a wide-bandgap semiconductor that is rendered electronically active by incorporating a hole dopant, boron. While the effects of boron doping on the electronic band structure of diamond are well-studied, any link between charge carriers and plasmons has never been shown.
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