Ammonia has emerged as a promising fuel for solid oxide fuel cells (SOFCs) owing to its high energy density, high hydrogen content, and carbon-free nature. Herein, the electrocatalytic potential of a novel Ni-doped SFM double-perovskite (SrFeNiMoO) is studied, for the first time, as an alternative anode material for symmetrical direct-ammonia SOFCs. Scanning and transmission electron microscopy characterization has revealed the exsolution of Ni-Fe nanoparticles (NPs) from the parent SrFeMoO under anode conditions, and X-ray diffraction has identified the FeNi phase after exposure to ammonia at 800 °C.
View Article and Find Full Text PDFIn this work, palladium nanoparticles were synthesized using one-pot synthesis utilizing porcine gastric mucin glycoproteins as reducing and capping agents. It is shown that the particles exhibited noticeable catalytic activity through both nitrophenol reduction and Suzuki-Miyaura coupling reactions. The catalytic performance was demonstrated with exceptionally high product yield, a fast reaction rate, and low catalyst use.
View Article and Find Full Text PDFBiological and synthetic molecular motors, fueled by various physical and chemical means, can perform asymmetric linear and rotary motions that are inherently related to their asymmetric shapes. Here, we describe silver-organic micro-complexes of random shapes that exhibit macroscopic unidirectional rotation on water surface through the asymmetric release of cinchonine or cinchonidine chiral molecules from their crystallites asymmetrically adsorbed on the complex surfaces. Computational modeling indicates that the motor rotation is driven by a pH-controlled asymmetric jet-like Coulombic ejection of chiral molecules upon their protonation in water.
View Article and Find Full Text PDFIn metallurgy, many intermetallic compounds crystallize as nanosized particles in metallic matrices. These particles influence dramatically the physical properties of engineering materials such as alloys and steels. Since properties and crystal structure are intimately linked, characterization of the atomic model of these intermetallides is crucial for the development of new alloys.
View Article and Find Full Text PDFMaterials (Basel)
February 2018
During the exploitation of nuclear reactors, various U-Al based ternary intermetallides are formed in the fuel-cladding interaction layer. Structure and physical properties of these intermetallides determine the radiation resistance of cladding and, ultimately, the reliability and lifetime of the nuclear reactor. In current research, U(Al, Si)₃ composition was studied as a potential constituent of an interaction layer.
View Article and Find Full Text PDFSemiconductors with chiral geometries at the nanoscale and mesoscale provide a rich materials platform for polarization optics, photocatalysis, and biomimetics. Unlike metallic and organic optical materials, the relationship between the geometry of chiral semiconductors and their chiroptical properties remains, however, vague. Homochiral ensembles of semiconductor helices with defined geometries open the road to understanding complex relationships between geometrical parameters and chiroptical properties of semiconductor materials.
View Article and Find Full Text PDFACS Appl Mater Interfaces
May 2016
Transition metal dichalcogenides (TMDCs) have been known for decades to have unique properties and recently attracted broad attention for their two-dimensional (2D) characteristics. NbSe2 is a metallic TMDC that has been studied for its charge density wave transition behavior and superconductivity but is still largely unexplored for its potential use in engineered devices with applications in areas such as electronics, optics, and batteries. Thus, we successfully demonstrate and present evidence of lithium intercalation in NbSe2 as a technique capable of modifying the material properties of NbSe2 for further study.
View Article and Find Full Text PDFIn bottom-up synthesis, products from reactions of structural building units rapidly pass from soluble molecular complexes to nanoscale intermediates, whose solution-state structures defy elucidation by any routine method. To address this, electron diffraction is used to reveal the structures of cryogenically "trapped" colloidal nanocrystals.
View Article and Find Full Text PDFWe report a new phase in the binary SnS system, obtained as highly symmetric nanotetrahedra. Due to the nanoscale size and minute amounts of these particles in the synthesis yield, the structure was exclusively solved using electron diffraction methods. The atomic model of the new phase (a = 11.
View Article and Find Full Text PDFActa Crystallogr B Struct Sci Cryst Eng Mater
December 2014
The crystal structure of the novel Al77Rh15Ru8 phase (which is an approximant of decagonal quasicrystals) was determined using modern direct methods (MDM) applied to automated electron diffraction tomography (ADT) data. The Al77Rh15Ru8 E-phase is orthorhombic [Pbma, a = 23.40 (5), b = 16.
View Article and Find Full Text PDFActa Crystallogr B Struct Sci Cryst Eng Mater
June 2014
The industrial importance of the U-Al-Si system stems from the fact that during processing the Al-based alloy (containing Si as impurity), used for the cladding of U (fuel in nuclear reactors), undergoes heat treatment which stimulates diffusion between the fuel and the cladding. One of the possible ways to represent the ternary U-Al-Si phase diagram is the construction of an UAl3-USi3 quasi-binary phase diagram. On the one hand, since the UAl3 and USi3 phases are isostructural, an isomorphous phase diagram is expected; on the other hand, some researchers observed a miscibility gap at lower temperatures.
View Article and Find Full Text PDFElectrostatically stabilized monolayer shells of metal-oxide cluster anions (polyoxometalates, or POMs) on the surfaces of ca. 8 nm tetrahedral and octahedral gold nanocrystals regioselectively direct water-soluble alkanethiolate ligands to the corners and edges of the gold polyhedra.
View Article and Find Full Text PDFCryogenic transmission electron microscopy of polyoxometalate-protected gold nanoparticles reveals that the Preyssler ion, [NaP(5)W(30)O(110)](14-), lies "face down" with its C(5) axis perpendicular to the gold surface, while the Finke-Droege ion, [P(4)W(30)Zn(4)(H(2)O)(2)O(112)](16-), is "tilted", with its long axis close to 60° from the normal to the surface.
View Article and Find Full Text PDF"Out-of-pocket" association of Ag(+) to the tetradentate defect site of mono-vacant Keggin and Wells-Dawson polyoxometalate (POM) cluster-anions is used to direct the formation of water-soluble AgCl nanocubes.
View Article and Find Full Text PDFCryogenic "trapping" was used to obtain the first TEM images of self-assembled monolayers of inorganic anions on a gold nanoparticle. This unique structural information makes it possible to study the formation of a protecting-ligand shell at an unprecedented level of detail. The protecting ligands are polyoxometalates (POMs; alpha-X(n+)W(12)O(40)((8-n)-), X(n+) = Al(3+) and "2H(+)", and alpha-X(n+)W(11)O(39)((12-n)-), X(n+) = P(5+), Si(4+), and Al(3+)) with large negative charges for association with the gold surface and W atoms (Z = 74) for TEM imaging.
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