ABSTRACT
Rubidium dicalcium triniobate(V), RbCa(2)Nb(3)O(10), has been synthesized by solid-state reaction and its crystal structure refined from X-ray powder diffraction data using Rietveld analysis. The compound is a three-layer perovskite Dion-Jacobson phase with the perovskite-like slabs derived by termination of the three-dimensional CaNbO(3) perovskite structure along the ab plane. The rubidium ions (4/mmm symmetry) are located in the inter-stitial space.
ABSTRACT
A new type of prickly nickel microwires assembled by thornlike nanocrystals was fabricated through a simple chemical reduction route with the assistance of citrate. Thus-prepared nickel wires were subsequently morphology-retained modified with a thin silver shell via transmetallation. Compared with the uncoated sample, the Ni(core)-Ag(shell) wires exhibited much-enhanced oxidation resistance, slightly changed magnetic properties and stark different catalysis for the creation of carbon particles in pyrolyzing acetone.
ABSTRACT
Spherical ceria (CeO(2)) crystallites assembled by nanoparticles were synthesized by hydrothermal treatment of Ce(NO(3))(3)6H(2)O using poly(N-vinyl-2-pyrrolidone) (PVP) as surfactant. It was found that these spheres were developed from the gradual aggregation of small nanoparticles and size of the spheres could be tailored by adjusting the reagent concentrations. Electrochemical tests indicated that thus-prepared CeO(2) spheres exhibited size-dependent discharge capacities and good cyclability in the Li/CeO(2) couple, showing their promising usages as anode materials in the lithium ion battery.
ABSTRACT
A simple and efficient microemulsion-based technique, which used the new Tx-100/cyclohexanol/ H2O system, was developed to synthesize SrCrO4 nanowire based nanostructures, including nanowire bundles and flower-like structures at different temperature. X-ray powder diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) were used to characterize the products. Studies found that the reaction temperatures and the reaction systems have great influences on the final products. Optical properties studies by UV-Vis spectra and photoluminescence (PL) spectra confirmed that the as-obtained nanowires showed distinct optical activity under UV and visible light irradiation.
Subject(s)
Chromates/chemistry , Crystallization/methods , Emulsions/chemistry , Nanostructures/chemistry , Nanostructures/ultrastructure , Nanotechnology/methods , Strontium/chemistry , Surface-Active Agents/chemistry , Materials Testing , Molecular Conformation , Particle SizeABSTRACT
Rodlike Fe particles were prepared by reduction of iron salts with hydrazine hydrate in the presence of CTAB. The as-prepared powders were characterized in detail by conventional techniques such as X-ray diffraction, and scanning electron microscopy, and their magnetic properties were evaluated on a vibrating sample magnetometer.
Subject(s)
Cetrimonium Compounds/chemistry , Hydrazines/chemistry , Iron/chemistry , Nanostructures/chemistry , Surface-Active Agents/chemistry , Cetrimonium , Microscopy, Electron, Scanning/methods , Particle Size , Sensitivity and Specificity , Surface Properties , X-Ray DiffractionABSTRACT
High-quality large-area beta-MnO(2) nanowires can be easily synthesized using KNO(3) as the mineralizing agent in a process of mineralization from Mn(NO(3))(2) aqueous solution. The morphological evolution of the beta-MnO(2) nanowires and the influences of mineralizing agents and their concentrations on the morphology of the final products were investigated in detail. KNO(3) was the best mineralizing agent among KNO(3), NaNO(3), KCl, and NaCl. More interestingly, when the concentration of the mineralizing agent KNO(3) was not saturated, only irregular short faceted nanorods, instead of nanowires, can be observed. Finally, the formation mechanism is discussed.
ABSTRACT
Single-crystal MnWO(4) nanofibres with diameters as small as 3-4 nm and length up to 800-1000 nm have been successfully synthesized by a novel surfactant-assisted complexation-precipitation method. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and electron diffraction (ED) were employed to study the crystal structure and morphologies of the products. Experiments show that the complexation and the surfactant are the crucial factors affecting the morphology of the products. The possible formation process and growth mechanism have been proposed.
