Preparation of a GdCaAl3O7 matrix by the non-hydrolytic sol–gel route

Matos, Marcela G.; Pereira, Paula Fabiana dos Santos; Calefi, Paulo S.; Ciuffi, Kátia J.; Nassar, Eduardo J.

doi:10.1016/j.jlumin.2009.03.003

Cited by 20 publications

(14 citation statements)

References 38 publications

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“…Therefore, these methods are somewhere between HSG and NHSG approach similar to the application of carboxylic acids in NHSG. However this method proved to be successful in the synthesis of amorphous mixed metal oxides [132][133][134][135][136][137][138][139][140][141][142][143]. Alcohols (and silanols) can also react with Si-H groups providing hybrid porous materials or building blocks based on Si-O-Si and Si-O-C bonds (condensation catalyzed by Et 2 NOH) [117,144,145].…”

Section: Alcohols In Nhsgmentioning

confidence: 99%

“…YAG doping with Tm 3+ , Tb 3+ , and Eu 3+ was found to be beneficial for tuning of photoluminescent properties by means of different color emission. The same group utilized a similar synthetic procedure to prepare other luminescent materials as well: several phases of Gd-O-Al mixed oxides doped with Eu 3+ [186], Eu 3+ :YVO 4 [134], and Eu 3+ :GdCaAl 3 O 7 [135].…”

Section: New Compositionsmentioning

confidence: 99%

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The Power of Non-Hydrolytic Sol-Gel Chemistry: A Review

et al. 2017

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This review is devoted to non-hydrolytic sol-gel chemistry. During the last 25 years, non-hydrolytic sol-gel (NHSG) techniques were found to be attractive and versatile methods for the preparation of oxide materials. Compared to conventional hydrolytic approaches, the NHSG route allows reaction control at the atomic scale resulting in homogeneous and well defined products. Due to these features and the ability to design specific materials, the products of NHSG reactions have been used in many fields of application. The aim of this review is to present an overview of NHSG research in recent years with an emphasis on the syntheses of mixed oxides, silicates and phosphates. The first part of the review highlights well known condensation reactions with some deeper insights into their mechanism and also presents novel condensation reactions established in NHSG chemistry in recent years. In the second section we discuss porosity control and novel compositions of selected materials. In the last part, the applications of NHSG derived materials as heterogeneous catalysts and supports, luminescent materials and electrode materials in Li-ion batteries are described.

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Section: Alcohols In Nhsgmentioning

confidence: 99%

Section: New Compositionsmentioning

confidence: 99%

The Power of Non-Hydrolytic Sol-Gel Chemistry: A Review

et al. 2017

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“…A typical sol-gel method is based on hydrolysis and condensation of the precursor (inorganic metal salts or metal organic compounds such as metal alkoxides) [24]. This process can be employed for the synthesis of functionalized inorganic oxides with controlled particle size and shape [35][36][37][38][39][40][41][42]. In the sol-gel method, control of the reactivity of the metal alkoxides used as precursors is very important in order to obtain sols and gels with desirable properties.…”

Section: Introductionmentioning

confidence: 99%

The influence of addition of a catalyst and chelating agent on the properties of titanium dioxide synthesized via the sol–gel method

Siwińska-Stefańska

Zdarta

Paukszta

et al. 2015

J Sol-Gel Sci Technol

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Titanium dioxide powders were prepared via the sol-gel method, using titanium alkoxide as a precursor. It was investigated how the addition of a catalyst (ammonia) and chelating agent (acetylacetone), as well as the temperature of calcination, affects the properties of the resulting TiO 2 powder. The physicochemical properties of samples were determined, including the dispersion, morphology and microstructure of the systems (particle size distribution, TEM images), crystalline structure (XRD), characteristics of porous structure (BET), and thermal stability (TGA/DTA). The samples were also analyzed using Fourier transform infrared spectroscopy. In addition, for selected TiO 2 systems, their photocatalytic activity in the decomposition of C.I. Basic Blue 9 was investigated. Our research results show that the presence of chelating agent in the synthesis of titanium dioxide caused significant changes in dispersive properties, crystalline structure and porous structure parameters. The novel feature of this work is the proposed method of synthesis of highly photoactive titanium dioxide with desirable physicochemical properties in the presence of a chelating agent such as acetylacetone. Graphical Abstract

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“…Os precursores metálicos utilizados na preparação da matriz de YVO 4 , YCl 3 , EuCl 3 e VOCl 4 foram obtidos conforme descrito por Matos et al 20,28,33,38 Os respectivos óxidos foram calcinados à 900 o C e dissolvidos em HCl para a formação dos respectivos cloretos. As massas necessárias foram pesadas para a obtenção da solução de concentração de 0,1 mol L -1…”

Section: Experimental Preparo Dos Precursoresunclassified

“…24 Uma variedade de redes hospedeiras podem ser obtidas por essa metodologia. 20,[25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] Diante disso, o objetivo deste trabalho foi obter por meio do processo sol gel rota não-hidrolítica a matriz de YVO 4 dopadas com o íon ativador Eu 3+ e Bi 3+ como sensibilizador, ambos em diferentes concentrações com o intuito de promover a intensificação da emissão do íon Eu 3+ . As caracterizações foram realizadas através da difração de raios X para identificação da fase cristalina formada e fotoluminescência do íon Eu 3+ avaliando as propriedades espectroscópicas.…”

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EFEITO DA CONCENTRAÇÃO DOS ÍONS Eu3+ E Bi3+ NAS PROPRIEDADES FOTOLUMINESCENTE DA MATRIZ DE YVO4

Matos¹,

Faria²,

Ciuffi³

et al. 2018

Quim. Nova

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. Inorganic matrices have been extensively studied for several applications, mainly doped with lanthanoid ions presenting special spectroscopic properties. The radiation emission can be affected by several factors, such as; matrix, synthesis methodology, activating ions and sensitizers, and concentrations. Thus, in this work the matrix of yttrium vanadate doped with Eu 3+ ions as activator and Bi 3+ ions as sensitizer was prepared by the non-hydrolytic sol-gel methodology. Europium (III) and Bismuth (III) ions concentrations were varied in 1, 3 and 5% in mol with respect to the Y 3+ ion and the samples were heat treated at 1000 °C. The X-ray diffraction analyzes showed a single phase of the yttrium vanadate matrix, indicating the non-influence of the dopant ions on the crystalline structure. The dopants concentrations presented influences on the spectroscopic properties of the emitting ion, the intensity parameters (W 2 e W 4 ), increased as a function of the increase of Bi 3+ concentration, affecting the covalence of the bond and the rigidity of the system. The increase of Eu 3+ concentration directly affected its environment, decreasing the symmetry and increasing the quantum efficiency. Finally, increasing the dopant ions promoted the decreasing the crystallite size.Keywords: sol-gel non-hydolytic; Judd-Ofelt parameter; lifetime; quantum efficience. INTRODUÇÃOAtualmente a aplicação dos elementos lantanóides tem sido vasta, englobando craqueamento de petróleo, catalisador automotivo, imãs permanentes, lasers, ligas, eletrônica, iluminação, concentradores solares, bio-análises, imageamento, visão noturna, comunicação, entre outros. 1Diante de tantas aplicações, as propriedades luminescentes são de suma importância, a utilização em pequenas quantidades como ativadores ou dopantes em matrizes hospedeiras, preservam suas características espectroscópicas, tais como: tempo de vida na ordem de milissegundos, finas bandas de emissão e grande deslocamento Stokes. sendo a rota sol-gel não-hidrolítica importante para a formação dos óxidos inorgânicos, empregando solventes orgânicos e sais metáli-cos como precursores. Esta rota promove a formação de partículas inorgânicas de diversas formas e tamanhos influenciada pela escolha do solvente que atua como doador de oxigênio. 24 Uma variedade de redes hospedeiras podem ser obtidas por essa metodologia. 20,[25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] Diante disso, o objetivo deste trabalho foi obter por meio do processo sol gel rota não-hidrolítica a matriz de YVO 4 dopadas com o íon ativador Eu 3+ e Bi 3+ como sensibilizador, ambos em diferentes concentrações com o intuito de promover a intensificação da emissão do íon Eu 3+ . As caracterizações foram realizadas através da difração de raios X para identificação da fase cristalina formada e fotoluminescência do íon Eu 3+ avaliando as propriedades espectroscópicas. EXPERIMENTAL Preparo dos precursoresOs precursores metálicos utilizados na preparação da matriz de YVO 4 , YCl 3 , EuCl 3 e VOCl ...

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Preparation of a GdCaAl3O7 matrix by the non-hydrolytic sol–gel route

Cited by 20 publications

References 38 publications

The Power of Non-Hydrolytic Sol-Gel Chemistry: A Review

The Power of Non-Hydrolytic Sol-Gel Chemistry: A Review

The influence of addition of a catalyst and chelating agent on the properties of titanium dioxide synthesized via the sol–gel method

EFEITO DA CONCENTRAÇÃO DOS ÍONS Eu3+ E Bi3+ NAS PROPRIEDADES FOTOLUMINESCENTE DA MATRIZ DE YVO4

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