On the Effect of Standard Deviation of Cationic Radii on the Transition Temperature in Fluorite-Structured Entropy-Stabilized Oxides (F-ESO).

It is confirmed that Fluorite-structured Entropy-Stabilized Oxides (F-ESO) can be obtained with multicomponent (5) equimolar systems based on cerium, zirconium, and other rare earth elements, selected according to the predictor already proposed by the authors. Indeed, in the present study, three different samples owning a standard deviation (SD in the following) of their cationic radii greater than the threshold value (i.e.

Reverse Micelle Strategy for the Synthesis of MnO -TiO Active Catalysts for NH-Selective Catalytic Reduction of NO at Both Low Temperature and Low Mn Content.

MnO -TiO catalysts (0, 1, 5, and 10 wt % Mn nominal content) for NH-SCR (selective catalytic reduction) of NO have been synthesized by the reverse micelle-assisted sol-gel procedure, with the aim of improving the dispersion of the active phase, usually poor when obtained by other synthesis methods (e.g., impregnation) and thereby lowering its amount.

Effective Inclusion of Sizable Amounts of Mo within TiO Nanoparticles Can Be Obtained by Reverse Micelle Sol-Gel Synthesis.

Six Mo/TiO samples (with 0, 1.0, 2.5, 5.

Separation of Biological Entities From Human Blood by Using Magnetic Nanocomposites Obtained From Zeolite Precursors.

In this work, three novel magnetic metal-ceramic nanocomposites were obtained by thermally treating Fe-exchanged zeolites (either A or X) under reducing atmosphere at relatively mild temperatures (750-800 °C). The so-obtained materials were thoroughly characterized from the point of view of their physico-chemical properties and, then, used as magnetic adsorbents in the separation of the target gene factors V and RNASE and of the bacteria DNA from human blood. Such results were compared with those obtained by using a top ranking commercial separation system (namely, SiMAG-N-DNA by Chemicell).

Entropy-Stabilized Oxides owning Fluorite Structure obtained by Hydrothermal Treatment.

Entropy-Stabilized Oxides (ESO) is a modern class of multicomponent advanced ceramic materials with attractive functional properties. Through a five-component oxide formulation, the configurational entropy is used to drive the phase stabilization over a reversible solid-state transformation from a multiphase to a single-phase state. In this paper, a new transition metal/rare earth entropy-stabilized oxide, with composition CeZrYGdLaO, was found after several investigations on alternative candidate systems.

New Insights in the Hydrothermal Synthesis of Rare-Earth Carbonates.

The rare-earth carbonates represent a class of materials with great research interest owing to their intrinsic properties and because they can be used as template materials for the formation of other rare earth phases, particularly of rare-earth oxides. However, most of the literature is focused on the synthesis and characterization of hydroxycarbonates. Conversely, in the present study we have synthesized both rare-earth carbonates-with the chemical formula RE(CO)·2-3HO, in which RE represents a generic rare-earth element, and a tengerite-type structure with a peculiar morphology-and rare-earth hydroxycarbonates with the chemical formula RECOOH, by hydrothermal treatment at low temperature (120 °C), using metal nitrates and ammonium carbonates as raw materials, and without using any additive or template.

Gd/Sm-Pr Co-Doped Ceria: A First Report of the Precipitation Method Effect on Flash Sintering.

In this work, ceria-based ceramics with the composition GdPrCeO and SmPrCeO, were synthesized by a simple co-precipitation process using either ammonium carbonate or ammonia solution as a precipitating agent. After the calcination, all of the produced samples were constituted by fluorite-structured ceria only, thus showing that both dopant and co-dopant cations were dissolved in the fluorite lattice. The ceria-based nanopowders were uniaxially compacted and consequently flash-sintered using different electrical cycles (including current-ramps).

Controlled Coprecipitation of Amorphous Cerium-Based Carbonates with Suitable Morphology as Precursors of Ceramic Electrolytes for IT-SOFCs.

To be suitable as electrolytes in intermediate temperature solid oxide fuel cell (IT-SOFC), ceramic precursors have to be characterized by high sintering aptitude for producing fully densified products which are needed for this kind of application. Therefore, synthesis processes able to prepare highly reactive powders with low costs are noteworthy to be highlighted. It has been shown that amorphous coprecipitates based on cerium doped (and codoped) hydrated hydroxycarbonates can lead to synthesized ceramics with such desired characteristics.

Preparation and Characterization of Magnetic and Porous Metal-Ceramic Nanocomposites from a Zeolite Precursor and Their Application for DNA Separation.

In this work, metal-ceramic nanocomposites were obtained through short (up to 2 h) thermal treatments at relatively moderate temperatures (750–800 °C) under a reducing atmosphere, using Fe-exchanged zeolite A as the precursor. The as-obtained materials were characterized by X-ray powder diffraction analysis, N2 adsorption at –196 °C, and highresolution transmission electron microscopy. The results of these analyses showed that the nanocomposites consisted of a dispersion of metallic Fe nanoparticles within a porous ceramic matrix, mainly based on amorphous silica and alumina.

Effect of the mineralizer solution in the hydrothermal synthesis of gadolinium-doped (10% mol Gd) ceria nanopowders.

Background: Gadolinium-doped ceria is an attractive electrolyte material for potential application in solid oxide fuel cells (SOFCs) operating at intermediate temperatures typically with 10%-20% substitution of Ce+4 by Gd+3. In particular, 10% gadolinium-doped ceria seems to have the highest values of conductivities among the other dopant compositions.

Methods: Nanosized powders of gadolinium-doped ceria were prepared by hydrothermal treatment using coprecipitate as a precursor and in the presence of 3 different mineralizer solutions.

Electrical and microstructural characterization of ceramic gadolinium-doped ceria electrolytes for ITSOFCs by sol-gel route.

Background: Gadolinium-doped ceria (GDC) is a promising alternative as a solid electrolyte for intermediate temperature solid oxide fuel cells (ITSOFCs) due to its low operating temperature and its high electrical conductivity. The traditional synthesis processes require extended time for powder preparation. Sol-gel methodology for electrolyte fabrication is more versatile and efficient.