Nanostructured Yttria Powders Via Gel Combustion

Abstract

Nanostructured yttria powders were prepared by a gel combustion technique. The technique involves exothermic decomposition of an aqueous citrate-nitrate gel. The decomposition is based on a thermally induced anionic redox reaction. A variety of yttria powders with different agglomerate structures can be made by altering the citrate-nitrate ratio γ. The gel with γ = 0.098 in situ yields nanostructured yttria powder at 258 °C that is porous and agglomerated with an average of 25 nm primary particles. Its specific surface area is 55 m2/g. The decomposition of the gels was investigated by simultaneous thermogravimetry analysis (TGA) and differential thermal analysis (DTA) experiments. The produced ashes and calcined powders are characterized by x-ray diffraction (XRD), ir spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brunauer, Emmett, and Teller (BET) analysis.

A Rapid Microwave-Induced Solution Combustion Synthesis of Ceria-Based Mixed Oxides for Catalytic Applications

“…These features make combustion synthesis an attractive method for the manufacture of technologically useful materials at lower costs compared to the conventional processes [15]. Among various combustion routes, preparation of nanomaterials by solution combustion synthesis has received much attention due to its enormous advantages [16]. The typical advantages of solution combustion process over other combustion methods are: (1) a superior control over the homogeneity and stoichiometry of the products fixed by the solution process, (2) the possibility to incorporate desired impurity ions in the oxide hosts and prepare industrially useful materials, (3) the process is simple and fast, and (4) it does not require any special equipment as in other combustion methods.…”

Facile autocombustion synthesis of La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) perovskite via a modified complexing sol–gel process with NH4NO3 as combustion aid

“…The homogeneity in the molecular level suggests that no bulk diffusion block is needed to overcome during the phase transformation process; therefore, pure-phase composite oxides can be obtained after a mild heat treatment at relatively lower temperatures (<1000 • C) [1][2][3][4][5][6][7][8][9][10]. In addition to the energy savings, the lowering in the synthesis temperature has additional derived benefits, such as high surface area and nanoparticle size ders [25][26][27][28][29][30]. It takes advantage of the fast exothermic chemical reactions between the organic and the oxidant in the gel.…”

La2CuO4 sensing electrode configuration influence on sensitivity and selectivity for a multifunctional potentiometric gas sensor

“…In addition, it is non-catalytic for the reduction of NO [6] and highly catalytic for the reduction of NO 2 and oxidation of CO [7]. La 2 CuO 4 powders were synthesized via an amorphous citrate gel combustion method [8]. Solutions of nitrates of La and Cu were prepared.…”