Particle size tailoring and luminescence of europium(III)-doped gadolinium oxide obtained by the modified homogeneous precipitation method: Dielectric constant and counter anion effects

TiO2 nanocrystalline powder was synthesized by homogeneous precipitation method using urea, and its characteristics were investigated through comparison with the powder prepared by conventional precipitation using ammonia. The homogeneously precipitated powder was anatase-type TiO2 with a particle size of 4–5 nm and a uniform spherical particle shape. The fact that the transformation from anatase to rutile was prohibited at elevated temperatures in the homogeneously precipitated powder can be useful to prepare anatase-type TiO2 thin films by calcination at high temperatures. With increasing heat-treatment temperature, the particle size of the homogeneously precipitated powder was smaller than that of the conventionally precipitated powder, and the particle shape was more uniform. The homogeneously precipitated powder showed good photocatalytic activity for Ag ion photoadsorption because the powder had both good crystallinity and a large specific surface area of 280 m2/g.

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Synthesis of Spherical Zinc Oxide Micro-Flower via an Electric Field-Assisted Homogeneous Precipitation Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.328-330.1541 ◽

2011 ◽

Vol 328-330 ◽

pp. 1541-1544 ◽

Cited By ~ 1

Author(s):

Xiu Juan Liang ◽

Xiao Fang Hu ◽

Xing Xing Weng ◽

Da Wei Hu ◽

Hai Xu Ji

Keyword(s):

Crystal Structure ◽

Particle Size ◽

Zinc Oxide ◽

Electric Field ◽

Precipitation Method ◽

Homogeneous Precipitation ◽

Homogeneous Precipitation Method ◽

Ft Ir ◽

Particle Size And Morphology ◽

Size And Morphology

This paper presents the experimental results on electric field-assisted synthesis of spherical Zinc Oxide (ZnO) micro-flower in an homogeneous precipitation method. The synthesis processes with and without an electric field were compared. The products were characterized via SEM, XRD, TGA and FT-IR spectrum. The results show that the spherical ZnO micro-flower composed of ZnO single crystalline nanoparticles have thickness of about 10nm, width of about 50nm.The SEM results show that the application of an electric field caused the morphology transformation from flake-like to flower-like. It was found that an electric field had an effect on the crystal structure,the particle size and morphology.

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Upconversion luminescence properties of monodisperse spherical Y2O2S:Yb,Ho nanocrystals

Journal of Materials Research ◽

10.1557/jmr.2009.0208 ◽

2009 ◽

Vol 24 (5) ◽

pp. 1756-1760 ◽

Cited By ~ 11

Author(s):

Xixian Luo ◽

Wanghe Cao ◽

Mingming Xing

Keyword(s):

Particle Size ◽

Low Temperature ◽

Formation Mechanism ◽

In Vivo Imaging ◽

Upconversion Luminescence ◽

Green Emission ◽

Precipitation Method ◽

Homogeneous Precipitation ◽

Homogeneous Precipitation Method

Monodisperse spherical Y2O2S:Yb,Ho nanocrystals with particle size about 50 nm were prepared by a modified homogeneous precipitation method combined with low-temperature sulfurization process. The Y2O2S:Yb,Ho nanocrystals exhibit an intense green emission assigned to the Ho3+ ions 5F4, 5S2 → 4I15/2 transition under 980 nm infrared pump. The upconversion luminescence brightness of Y2O2S:Yb,Ho is 526 Cd/m2 under 4.63 W/cm2 pump density, indicating that the as-prepared Y2O2S:Yb,Ho nanocrystals can meet the requirement of in vivo imaging. The formation mechanism of monodisperse spherical oxysulfide nanoparticles is also discussed.

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Synthesis of Calcium Carbonate from Calcium Chlorine Solution Using Homogeneous Precipitation Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.486-487.542 ◽

2005 ◽

Vol 486-487 ◽

pp. 542-545 ◽

Cited By ~ 1

Author(s):

Kyung Nam Kim ◽

Dae Yong Shin ◽

Se Gu Son ◽

Yong Do Kim

Keyword(s):

Particle Size ◽

Calcium Carbonate ◽

Precipitation Method ◽

Homogeneous Precipitation ◽

Reaction Conditions ◽

Homogeneous Precipitation Method ◽

Reaction Solution ◽

Particle Size And Morphology ◽

Size And Morphology ◽

Hydrolysis Of

Calcium carbonate(CaCO3) was synthesized from aqueous CaCl2 solution, using the homogeneous precipitation technique, which uses the hydrolysis of urea. The effects of reaction conditions on the morphology of CaCO3 were examined at 50-90°C. Particle size of CaCO3 decreases, as the concentrations of urea and [Ca2+] are increased. Calcite is produced more, as the concentration of [Ca2+] is increased. Method to stir the reaction solution affects significantly the particle size and morphology of CaCO3. Uniform needle-like aragonite particles were obtained, when left at 90°C for 4hours without stirring.

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Synthesis of ZnO Nanopowders by the Homogeneous Precipitation Method: Use of Taguchi’s Method for Analyzing the Effect of Different Variables

Journal of Nanomaterials ◽

10.1155/2017/4595384 ◽

2017 ◽

Vol 2017 ◽

pp. 1-9 ◽

Cited By ~ 5

Author(s):

R. Herrera-Rivera ◽

M. de la L. Olvera ◽

A. Maldonado

Keyword(s):

Particle Size ◽

Experimental Design ◽

Size Variation ◽

Statistical Technique ◽

Morphological Properties ◽

Precipitation Method ◽

Statistical Experimental Design ◽

Homogeneous Precipitation ◽

Taguchi’S Method ◽

Homogeneous Precipitation Method

In the present work the effect of different factors in the synthesis of ZnO powders by the homogeneous precipitation method is analyzed. A robust statistical technique, Taguchi’s method, was used to reduce the experiments number. The variables studied were precursor, solvent and precipitating agent type, Zn molar concentration, percentage of saturation, speed and time of agitation, and temperature of synthesis. In order to optimize the particle size, an experimental design of 18 trials was proposed, according to L18 Taguchi array. Structural and morphological properties were characterized by X-ray diffraction (XRD) and scanning and transmission electron microscopy techniques (SEM and TEM). The estimated crystallite size in synthesized samples ranged from 32 to 57 nm. The morphologies obtained presented several forms, such as spheres, wires, flowers, bars, and tetrahedrons, with a particle size variation of 35 to 165 nm. In this work it is shown that using a statistical experimental design leads us to a fast and reliable optimization of the synthesis parameters for obtaining small size ZnO nanoparticles, thus optimizing time and human and materials resources.

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Particle Size of Alumina Hydrate Gel Prepared by the Homogeneous Precipitation Method

Journal of the Ceramic Association Japan ◽

10.2109/jcersj1950.94.1090_601 ◽

1986 ◽

Vol 94 (1090) ◽

pp. 601-603

Author(s):

Kazumi FUJITA ◽

Satoshi KONNO ◽

Isao KAYAMA

Keyword(s):

Particle Size ◽

Precipitation Method ◽

Homogeneous Precipitation ◽

Alumina Hydrate ◽

Homogeneous Precipitation Method

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Synthesis and Characterization of Nanocrystalline Ceria Powder through Homogeneous Precipitation Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.557-559.567 ◽

2012 ◽

Vol 557-559 ◽

pp. 567-571

Author(s):

Jin Liang ◽

Hong Chen

Keyword(s):

Particle Size ◽

Orthogonal Experiment ◽

Fluorite Structure ◽

Precipitation Method ◽

Homogeneous Precipitation ◽

X Ray Diffraction ◽

X Ray ◽

Homogeneous Precipitation Method ◽

Nanocrystalline Ceria

Nanocrystalline ceria powder was prepared through homogeneous precipitation method, orthogonal experiment was designed to figure out the most important factor that influence the particle size of the resultant and the optimum condition. X-ray diffraction revealed that the as-prepared nanoscale ceria powder had cubic fluorite structure, TEM image showed that the ceria powder was weakly agglomerated with a particle size of about 10 nm.

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Luminescence Properties of Europium-Doped Yttrium Oxides Derived from Their Dodecylsulfate-Templated Mesostructure and Nanotube Forms

MRS Proceedings ◽

10.1557/proc-775-p3.2 ◽

2003 ◽

Vol 775 ◽

Cited By ~ 2

Author(s):

Tsuyoshi Kijima ◽

Kenichi Iwanaga ◽

Tomomi Hamasuna ◽

Shinji Mohri ◽

Mitsunori Yada ◽

...

Keyword(s):

Room Temperature ◽

Broad Band ◽

Concentration Quenching ◽

Precipitation Method ◽

Homogeneous Precipitation ◽

Bulk Materials ◽

Main Band ◽

Homogeneous Precipitation Method ◽

Order Of Magnitude ◽

Weak Luminescence

AbstractEuropium-doped hexagonal-mesostructured and nanotubular yttrium oxides templated by dodecylsulfate species as well as surfactant free bulk oxides were synthesized by the homogeneous precipitation method. All the as grown nanostructured or bulk materials with amorphous or poorly crystalline frameworks showed weak luminescence bands at room temperature. On calcination at 1000°C these materials were converted into highly crystalline yttrium oxides, resulting in a total increase in intensity of all the bands by one order of magnitude. In the hexagonal-mesostructured system, the main band due to the 5D0-7F2 transition for the calcined phases showed a sharp but asymmetrical multiplet splitting indicating multiple Eu sites. Concentration quenching was found at a Eu content of 3 mol% or above for these phases. In contrast, the main emission for the calcined solids in the nanotubular system occurred as poorly resolved broad band and the intensity of the main band at higher Eu content was significantly enhanced compared with those for the other two systems.

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Preparation of α-Ni(OH)2 with Flowerlike Hierarchical Architectures via Homogeneous Precipitation Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.284-286.684 ◽

2011 ◽

Vol 284-286 ◽

pp. 684-687

Author(s):

Chang Yu Li ◽

Li Li Liu ◽

Shou Xin Liu

Keyword(s):

Electron Microscopy ◽

Precipitation Method ◽

Homogeneous Precipitation ◽

X Ray ◽

Homogeneous Precipitation Method ◽

Α Phase ◽

Transmission Electron ◽

Hierarchical Architectures ◽

Flowerlike Structure ◽

Adsorption Desorption

Without using any templates or surfactants, flowerlike α-nickel hydroxide (Ni(OH)2) was successfully synthesized by homogeneous precipitation method. The prepared products were characterized by X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and N2 adsorption-desorption. The prepared Ni(OH)2 is α-phase with specific surface area of 245.0 m2/g and shows flowerlike structure with 4-6 um in diameter.

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