Amorphous SiHfBCN ceramics were prepared from a commercial polysilazane (HTT 1800, AZ-EM), which was modified upon reactions with Hf(NEt2)4 and BH3·SMe2, and subsequently cross-linked and pyrolyzed. The prepared materials were investigated with respect to their chemical and phase composition, by means of spectroscopy techniques (Fourier transform infrared (FTIR), Raman, magic-angle spinning nuclear magnetic resonance (MAS NMR)), as well as X-ray diffraction (XRD) and transmission electron microscopy (TEM). Annealing experiments of the SiHfBCN samples in an inert gas atmosphere (Ar, N2) at temperatures in the range of 1300-1700 °C showed the conversion of the amorphous materials into nanostructured UHTC-NCs. Depending on the annealing atmosphere, HfC/HfB2/SiC (annealing in argon) and HfN/Si3N4/SiBCN (annealing in nitrogen) nanocomposites were obtained. The results emphasize that the conversion of the single-phase SiHfBCN into UHTC-NCs is thermodynamically controlled, thus allowing for a knowledge-based preparative path toward nanostructured ultrahigh-temperature stable materials with adjusted compositions.
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http://dx.doi.org/10.1021/ic501512p | DOI Listing |
Molecules
December 2024
CP2M-ESCPE Lyon, CNRS, University Claude Bernard Lyon 1, UMR 5128, 43 Bd du 11 Nov. 1918, CEDEX, 69616 Villeurbanne, France.
TiO:Eu nanoparticles with varying europium concentrations were successfully synthesized via a one-pot sol-gel approach using a molecular heterometallic single-source precursor (SSP) Eu-Ti. For comparison, nanomaterials with similar europium levels were also produced by impregnating europium salts onto the same TiO substrate. All the nanomaterials were thoroughly characterized using Eu elemental analysis, powder X-ray diffraction (XRD), scanning (SEM), transmission (TEM), scanning transmission electron microscopy (STEM), Brunauer-Emmett-Teller (BET) analysis, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and photoluminescence (PL).
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Functional Materials and Electrochemistry Lab, Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India.
The rational design and synthesis of bifunctionally active and durable oxygen electrocatalysts have garnered significant attention for electrochemical energy conversion and storage. Intermetallic nanostructures are particularly promising for these applications due to their unique catalytic properties and exceptional durability. In this study, we present a fascinating synthetic approach for the direct synthesis of a bifunctional oxygen electrocatalyst based on nitrogen-doped carbon-encapsulated ordered PdFe (o-PdFe@NC) intermetallic, using a cyano-bridged bimetallic single-source precursor tailored for aqueous rechargeable zinc-air batteries (ZABs).
View Article and Find Full Text PDFNanoscale Adv
December 2024
Department of Chemical Engineering, University of Manchester Manchester M13 9PL UK
Nanocrystals are widely explored for a range of medical, imaging, sensing, and energy conversion applications. CdS nanocrystals have been reported as excellent photocatalysts, with thin film CdS also highly important in photovoltaic devices. To optimise properties of nanocrystals, control over phase, facet, and morphology are vital.
View Article and Find Full Text PDFJ Fluoresc
November 2024
CHRIST (Deemed to be University), Bengaluru, 560029, India.
Dalton Trans
October 2024
Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 IDB, UK.
Addition of two equivalents of NaSCNHBz to CuSO affords the yellow diamagnetic coordination polymer [Cu(SCNHBz)] (1), resulting from intramolecular electron-transfer and concomitant formation of the thiourea, (BzNH)CS. 1 reacts with PPh and 1,1'-bis(diphenylphosphino)ferrocene (dppf) in CHCl to give monomeric [Cu(κ-SCNHBz)(PPh)] (2) and [Cu(κ-SCNHBz)(κ-dppf)] (3), respectively, both of which have been crystallographically characterised. While 1 is thermally stable in dimethylsulfoxide (DMSO) up to 70 °C, addition of BuNH to 1 leads to its rapid decomposition to afford CuS (covellite) nanomaterials; indeed in neat BuNH, covellite formation is rapid at room temperature.
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