The formation of O(2) (-) radical anions by contact of O(2) molecules with a Na pre-covered MgO surface is studied by a combined EPR and quantum chemical approach. Na atoms deposited on polycrystalline MgO samples are brought into contact with O(2). The typical EPR signal of isolated Na atoms disappears when the reaction with O(2) takes place and new paramagnetic species are observed, which are attributed to different surface-stabilised O(2) (-) radicals. Hyperfine sublevel correlation (HYSCORE) spectroscopy allows the superhyperfine interaction tensor of O(2) (-)Na(+) species to be determined, demonstrating the direct coordination of the O(2) (-) adsorbate to surface Na(+) cations. DFT calculations enable the structural details of the formed species to be determined. Matrix-isolated alkali superoxides are used as a standard to enable comparison of the formed species, revealing important and unexpected contributions of the MgO matrix in determining the electronic structure of the surface-stabilised Na(+)-O(2) (-) complexes.
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http://dx.doi.org/10.1002/chem.201000546 | DOI Listing |
J Phys Chem C Nanomater Interfaces
January 2025
Furman University, Greenville, South Carolina 29613, United States.
Surface-anchored metal-organic frameworks (surMOFs) are crystalline, nanoporous, supramolecular materials mounted to substrates that have the potential for integration within device architectures relevant for a variety of electronic, photonic, sensing, and gas storage applications. This research investigates the thin film formation of the Cu-BDC (copper benzene-1,4-dicarboxylate) MOF system on a carboxylic acid-terminated self-assembled monolayer by alternating deposition of solution-phase inorganic and organic precursors. X-ray diffraction (XRD) and atomic force microscopy (AFM) characterization demonstrate that crystalline Cu-BDC thin films are formed via Volmer-Weber growth.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2025
Surface Science Laboratory, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland.
Nanopowders or films of pure and mixed oxides in nanoparticulate form have gained specific interest due to their applicability in functionalizing high-surface-area substrates. Among various other applications, our presented work primarily focuses on the behavior of TiO as a photocatalyst deposited by atomic layer deposition (ALD) on a quartz particle. The photocatalytic activity of TiO on quartz particles grown by ALD was studied in terms of ALD growth temperature and post-treatment heating rate.
View Article and Find Full Text PDFNano Lett
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Institute of Photoelectronic Thin Film Devices and Technology, State Key Laboratory of Photovoltaic Materials and Cells, Tianjin Key Laboratory of Efficient Solar Energy Utilization, Ministry of Education Engineering Research Center of Thin Film Photoelectronic Technology, Nankai University, 300350 Tianjin, China.
Hematite is a promising material for photoelectrochemical (PEC) water oxidation, but its photocurrent is limited by bulk charge recombination and poor oxidation kinetics. In this study, we report a high-performance FeO photoanode achieved through gradient surface gallium doping, utilizing a GaO overlayer on FeOOH precursors via atomic layer deposition (ALD) and co-annealing for Ga diffusion. The Ga-doped layer passivates surface states and modifies the band structure, creating a built-in electric field that enhances the charge separation efficiency.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States.
Lithium-sulfur (Li-S) batteries, with their superior energy densities, are emerging as promising successors to conventional lithium-ion batteries. However, their widespread adoption is hindered by challenges such as the shuttle effect of polysulfides, which affects discharge capacity and cycling stability. This study explores the transformative potential of atomic layer deposition (ALD) of AlO on commercial PP/PE/PP separators (Celgard), combined with the use of UV ozone exposure to enhance ALD nucleation on the separator surface, to address these challenges.
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Internal Dosimetry Section, Radiation Safety Systems Division, Bhabha Atomic Research Centre, Trombay, 400085, India.
Shadow Shield Whole Body Counter (SSWBC) is used to estimate internal dose of radiation workers due to the intake of fission and activation products. The SSWBC geometry was numerically modelled in FLUKA code. The computational model was validated by comparing the experimental and simulated counting efficiencies (CEs), also known as response, using Bhabha Atomic Research Centre (BARC) reference BOttle Mannequin Absorption (BOMAB) phantom.
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