(Mg,Ni)Ga2O4 Solid Solution with a Spinel Structure

Doklady Chemistry - The boundaries of Mg1 – xNixGa2O4 solid solutions (0 ≤ х ≤ 0.5) with a spinel structure synthesized by the gel combustion method,...     

Selective precipitation of rare earth orthophosphates with hydrogen peroxide from phosphoric acid solutions

It has been shown for the first time that the use of hydrogen peroxide allows precipitation of rare earth orthophosphates (La–Tb) from phosphoric acid solutions at temperatures below 100°C. Either anhydrous or hydrated orthophosphates with monazite or rhabdophane structure, respectively, can be obtained depending on rare earth element position in lanthanide series and precipitation conditions (orthophosphoric acid and hydrogen peroxide concentration). Hydrated orthophosphates with rhabdophane structure can be prepared by precipitation with hydrogen peroxide for all studied rare earth elements.     

Synthesis of manganese dioxide by homogeneous hydrolysis in the presence of melamine

A new selective method for the synthesis of nanocrystalline manganese dioxide (α-, β-, and γ-MnO₂) based on the reaction of potassium permanganate with 2,4,6-triamino-1,3,5-triazine (melamine) under hydrothermal conditions has been proposed. Effect of synthesis conditions on the phase composition of the products has been revealed. A new manganese-containing phase with layered structure has been prepared.     

Synthesis of cerium orthophosphates with monazite and rhabdophane structure from phosphoric acid solutions in the presence of hydrogen peroxide

It has been proposed to conduct the synthesis of cerium(III) orthophosphates by reacting cerium(IV) compounds with hydrogen peroxide in the presence of concentrated orthophosphoric acid at ambient temperature. It has been shown that the reaction of H₂O₂ with CeO₂ suspensions in H₃PO₄ medium produces CePO₄ · xH₂O (rhabdophane structure), while that with CeO₂ solutions in concentrated H₃PO₄ results in CePO₄ (monazite structure).     

Luminescent alumina-based aerogels modified with tris(8-hydroxyquinolinato)aluminum

A facile procedure was developed for the production of Al₂O₃ aerogels modified with tris(8-hydroxyquinolinato)aluminum complex (AlQ₃). The addition of 8-hydroxyquinoline during the stage of alumina lyogel formation was found to increase gelation duration. The translucent monolithic aerogels were obtained by supercritical drying of lyogels in CO₂. The composition and properties of aerogels were analyzed using low-temperature nitrogen adsorption, helium pycnometry, IR spectroscopy, UV–visible spectroscopy, luminescence spectroscopy, powder X-ray diffraction, scanning and transmission electron microscopy, and thermogravimetry combined with mass spectrometry. The obtained aerogels had low density (0.15–0.18?g?cm^?3), high specific surface area (480–550?m²/g), high porosity (90–95%), and showed bright luminescence upon excitation in the UV range.

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Hydrothermal Microwave Synthesis of MnO<Subscript>2</Subscript> in the Presence of Melamine: The Role of Temperature and pH

Nanocrystalline manganese dioxide have been prepared by hydrothermal microwave treatment of mixed solutions of potassium permanganate and 2,4,6-triamino-1,3,5-triazine (melamine) in pH range 0.5–3. Phase and chemical composition and morphology of the samples was studied by XRD, Raman spectroscopy, and SEM. Conditions (solution pH and temperature) for the formation of single phase MnO₂ powders (α-MnO₂, γ-MnO₂, δ-MnO₂, and δ*-MnO₂) under hydrothermal microwave treatment were determined.     

Cobalt-based ZIF-68 and ZIF-69 as the precursors of non-platinum electrocatalysts for oxygen reduction

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A Study of the Influence of Irradiation of Carbon Diamond-Like Coatings with Nanosecond Laser Pulses on Their Structural-Phase Composition and Tribological Properties

Russian Physics Journal - Using the methods of Raman spectroscopy, optical metallography and scanning electron microscopy, combined with the measurements of tribological characteristics, special...     

Laser damage threshold of hydrophobic up-conversion carboxylated nanocellulose/SrF2:Ho composite films functionalized with 3-aminopropyltriethoxysilane

Cellulose - Luminescent nanocomposite films, containing SrF2:Ho up-conversion particles, were prepared by two different protocols from aqueous dispersions of TEMPO-oxidized cellulose nanofibrils...