Preparation of Rare-Earth Doped Zirconia Nanoparticles via Supercritical Hydrothermal Method for Luminescence Properties

2012 ◽  
Vol 512-515 ◽  
pp. 59-64
Author(s):  
Yukiya Hakuta ◽  
Kiwamu Sue ◽  
Yoshihiro Takebayashi ◽  
Satoshi Yoda ◽  
Takeshi Furuya ◽  
...  
Keyword(s):  
Reaction Temperature ◽  
Hydrothermal Reaction ◽  
Reaction System ◽  
Zirconium Hydroxide ◽  
Luminescence Properties ◽  
Photoluminescence Spectra ◽  
Ion Species ◽  
Rare Earth Doped ◽  
Zirconia Nanoparticles ◽  
Electro Luminescence

We report preparation of Tb3+ or Eu3+ doped zirconia nanoparticles by sub- and supercritical hydrothermal reaction and luminescence properties. Experiments were performed by a flow-type hydrothermal reaction system. We investigated the effect of the reaction temperature on crystal structure, particle size and photo-, electro-luminescence properties. Reaction temperature was varied in the ranges of 150 to 400 C and reaction pressure was fixed to 30MPa. Characteristics of the products were performed by XRD, TEM, SEM-EDS and PL, EL measurements. The product transformed from amorphous zirconium hydroxide to tetragonal ZrO2 with an increase in the reaction temperature, regardless of the doped ion species. The ZrO2:Eu particles obtained at 400C were spherical with around 5 nm in diameter. ZrO2:Eu nanoparticles obtained under supercritical water condision showed typical photoluminescence spectra of f-f transition of Eu3+; however ZrO2:Tb nanoparticle obtained under the same condition showed no photoluminescence. Furthermore, the ZrO2:Eu nanoparticles obtained at 400 C showed high electroluminescence properties at electric field of 350V and 1kHz.

Syntheses, Structural Characterization and Fluorescence of Zn(II) and Cd(II) Polymers from 5-(Pyridin-2-ylmethylamino)isophthalic acid

2013 ◽  
Vol 68 (9) ◽  
pp. 1007-1014 ◽  
Author(s):  
Xiao-Chun Cheng ◽  
Xiao-Hong Zhu ◽  
Hai-Wei Kuai
Keyword(s):  
Water Clusters ◽  
Hydrothermal Reaction ◽  
Reaction System ◽  
Chain Structure ◽  
Isophthalic Acid ◽  
Auxiliary Ligand ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alkaline Reaction ◽  
A Chain

The hydrothermal reaction of Zn(II) nitrate with 5-(pyridin-2-ylmethylamino)isophthalic acid (H2L) yields the complex [Zn(L)(H2O)] 2H2O (1). When 2,2'-bipyridine (bpy) as auxiliary ligand and Cd(II) nitrate were used in the alkaline reaction system, [Cd(L)(H2O)(bpy)] 3H2O (2) was obtained. Complexes 1 and 2 have been characterized by single-crystal and powder X-ray diffraction, IR, elemental and thermogravimetric analyses. Complex 1 shows a 2D fes network structure with uninodal 3-connected (4.82) topology, which is further linked by hydrogen bonding to give rise to a 3D supramolecular framework; complex 2 displays a chain structure. Interestingly, tetranuclear water clusters were generated in 1, which are interlinked to fabricate a water chain structure. The fluorescence properties of 1 and 2 were investigated

scholarly journals The pH Value Control of Morphology and Luminescence Properties of Gd2O2S: Tb3+ Phosphors

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 646
Author(s):  
Peng Jiang ◽  
Zhipeng Li ◽  
Wei Lu ◽  
Yi Ma ◽  
Wenhuai Tian
Keyword(s):  
Electron Beam ◽  
Rare Earth ◽  
Ph Value ◽  
Uv Light ◽  
Hexagonal Phase ◽  
Band Gap Energy ◽  
Information Storage ◽  
Luminescence Properties ◽  
Research Fields ◽  
Rare Earth Doped

Developing rare-earth doped oxysulfide phosphors with diverse morphologies has significant value in many research fields such as in displays, medical diagnosis, and information storage. All of the time, phosphors with spherical morphology have been developed in most of the related literatures. Herein, by simply adjusting the pH values of the reaction solution, Gd2O2S:Tb3+ phosphors with various morphologies (sphere-like, sheet-like, cuboid-like, flat square-like, rod-like) were synthesized. The XRD patterns showed that phosphors with all morphologies are pure hexagonal phase of Gd2O2S. The atomic resolution structural analysis by transmission electron microscopy revealed the crystal growth model of the phosphors with different morphology. With the morphological change, the band gap energy of Gd2O2S:Tb3+ crystal changed from 3.76 eV to 4.28 eV, followed by different luminescence performance. The samples with sphere-like and cuboid-like microstructures exhibit stronger cathodoluminescence intensity than commercial product by comparison. Moreover, luminescence of Gd2O2S:Tb3+ phosphors have different emission performance excited by UV light radiation and an electron beam, which when excited by UV light is biased towards yellow, and while excited by an electron beam is biased towards cyan. This finding provides a simple but effective method to achieve rare-earth doped oxysulfide phosphors with diversified and tunable luminescence properties through morphology control.

Preparation of Nanosize Anatase TiO2 Powders by Hydrothermal Synthesis

2007 ◽  
Vol 336-338 ◽  
pp. 2017-2020 ◽  
Author(s):  
Fan Yong Ran ◽  
Wen Bin Cao ◽  
Yan Hong Li ◽  
Xiao Ning Zhang
Keyword(s):  
Grain Size ◽  
Hydrothermal Synthesis ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Reaction Temperature ◽  
Reaction System ◽  
Anatase Tio2 ◽  
Holding Time ◽  
Precursor Concentration

Nanosize anatase TiO2 powders have been synthesized by hydrothermal synthesis by using technical grade TiOSO4 as precursor and urea as precipitating agent. The initial pressure of the reaction system was set at 6 MPa. Stirring speed was fixed at 300r/min. The reaction system reacted at the temperature ranged from 110 to 150°C for holding 2hrs to 8hrs and the concentration of the precursor was ranged from 0.25M to1.5M. XRD patterns show that the synthesized powders are in the form of anatase phase. Calculated grain size is ranged from 6.7 to 8.9nm by Scherrer method from the line broadening of the (101) diffraction peak of anatase. The specific surface area of the powders synthesized under different conditions is ranged from 124 to 240m2/g. The grain size of the powders increases with the increase of the reaction temperature, holding time and precursor concentration, respectively. The specific surface area decreases with the increase of reaction temperature and holding time, and does not obviously change with the change of precursor concentration when the concentration of the precursor is less than 1M. However, when the concentration is higher than 1M, the specific surface area will decrease quickly with the increase of the precursor concentration. XRD and DSC-TG analysis shows that the synthesized anatase TiO2 will begin to transform to rutile TiO2 at about 840°C. When heated to 1000°C for holding 1h, the anatase powders will transform to rutile completely.

Luminescence properties of rare-earth-doped fluoride borate crystals

2021 ◽  
pp. 163343
Author(s):  
Tatyana B. Bekker ◽  
Alexey A. Ryadun ◽  
Alexey V. Davydov ◽  
Vladimir P. Solntsev ◽  
Veronika D. Grigorieva
Keyword(s):  
Rare Earth ◽  
Luminescence Properties ◽  
Rare Earth Doped

scholarly journals Tandem buildup of complexity of aromatic molecules through multiple successive electrophile generation in one pot, controlled by varying the reaction temperature

2016 ◽  
Vol 14 (5) ◽  
pp. 1680-1693 ◽  
Author(s):  
Akinari Sumita ◽  
Yuko Otani ◽  
Tomohiko Ohwada
Keyword(s):  
Reaction Temperature ◽  
Reaction System ◽  
Reaction Rates ◽  
Aromatic Molecule ◽  
One Pot ◽  
Aromatic Molecules

The unmasking reaction rates and the time of generation of highly reactive electrophiles can be controlled. This reaction system demonstrates the conceptual validity of one-pot build-up of a complex aromatic molecule from multiple starting components.

scholarly journals Construction of Carbon Microspheres-Based Silane Melamine Phosphate Hybrids for Flame Retardant Poly(ethylene Terephthalate)

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 545 ◽  
Author(s):  
Baoxia Xue ◽  
Ruihong Qin ◽  
Jie Wang ◽  
Mei Niu ◽  
Yongzhen Yang ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Ethylene Terephthalate ◽  
Hydrothermal Reaction ◽  
Reaction System ◽  
Fire Risk ◽  
Carbon Microspheres ◽  
Limiting Oxygen Index ◽  
Melamine Phosphate ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

To improve the flame retardancy and inhibit the smoke of poly(ethylene terephthalate) (PET), carbon microspheres (CMSs)-based melamine phosphate (MP) hybrids (MP-CMSs) were constructed in situ with the introduction of CMSs into the hydrothermal reaction system of MP. The integrated MP-CMSs were modified by 3-Aminopropyltriethoxysilane (APTS) to obtain the silane MP-CMSs (SiMP-CMSs) to strengthen the interface binding between the MP-CMSs and PET matrix. The results showed that the SiMP layer was loaded on the CMSs surface. The addition of only 3% SiMP-CMSs increased the limiting oxygen index (LOI) value of the PET from 21% ± 0.1% to 27.7% ± 0.3%, reaching a V-0 burning rate. The SiMP-CMSs not only reduced heat damage, but also inhibited the smoke release during PET combustion, whereupon the peak heat release rate (pk-HRR) reduced from 513.2 to 221.7 kW/m2, and the smoke parameters (SP) decreased from 229830.2 to 81892.3 kW/kg. The fire performance index (FPI) rose from 0.07 m2s/kW to 0.17 m2s/kW, demonstrating the lower fire risk. The proportion of the flame-retardant mode in the physical barrier, flame inhibition, and char effects were recorded as 44.53%, 19.04%, and 9.04%, respectively.

Zirconium metal organic framework for design of tetragonal rare earth-doped zirconia nanoparticles

2019 ◽  
Vol 37 (11) ◽  
pp. 1230-1236
Author(s):  
Lam Thi Kieu Giang ◽  
Łukasz Marciniak ◽  
Krzysztof Kamil Żur ◽  
Dinh Manh Tien ◽  
Nguyen Vu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Metal Organic Framework ◽  
Metal Organic ◽  
Zirconium Metal ◽  
Rare Earth Doped ◽  
Zirconia Nanoparticles ◽  
Organic Framework

scholarly journals Investigation of Bioactive Glass-Ceramic 60SiO2-30CaO-10P2O5 Prepared by Hydrothermal Method

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Vuong Xuan Bui ◽  
Mai Quang Vo ◽  
Tien Anh Nguyen ◽  
Hoa Thi Bui
Keyword(s):  
Bioactive Glass ◽  
Hydrothermal Method ◽  
Reaction Temperature ◽  
Hydrothermal Reaction ◽  
Glass Ceramics ◽  
Degree Of Crystallinity ◽  
Apatite Phase ◽  
Powder Samples ◽  
Sbf Solution ◽  
The Degree Of Crystallinity

Bioactive glass-ceramics (BGCs) with the composition of 60SiO2-30CaO-10P2O5 (wt. %) have been synthesized by the hydrothermal method. The BGC samples were prepared at two reaction temperatures of 150 and 220°C, named BGC-150 and BGC-220. The XRD and FTIR analyses highlighted that the degree of crystallinity of BGCs increased linearly with hydrothermal reaction temperature. FE-SEM and TEM results indicated that the surface of BGC samples is covered by the nanosized particles which grow into larger sizes as a function of reaction temperature. The bioactivity of BGCs was investigated by the immersion of powder samples in the SBF solution. The results confirmed the dissolution and the interaction of BGC samples in the SBF solution which led to the formation of a new apatite phase on their surface.

Hydrothermal Synthesis and Morphology Evolution of Perovskite PbTiO3 Crystals with Different Lead Sources

2013 ◽  
Vol 745-746 ◽  
pp. 309-314 ◽  
Author(s):  
Si Min Yin ◽  
Gang Xu ◽  
Zhao Hui Ren ◽  
Chun Ying Chao ◽  
Ge Shen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Reaction ◽  
Reaction System ◽  
Morphology Evolution ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Transmission Electron ◽  
Lead Source

Perovskite lead titanate crystals with various morphologies were successfully synthesized via a hydrothermal reaction route with different lead sources. X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) were employed to characterize the phase composition and the morphology of the synthesized products. In order to investigate the effect of the lead source on the phase formation and morphology evolution of the synthesized pervoskite PbTiO3 crystals, PbO, PbF2, PbSO4 and Pb (CH3COO)3 ·3H2O, were used as starting precursor lead source introduced into the hydrothermal reaction system, respectively. Accordingly, perovskite PbTiO3 brken cubes, irregular particles, cubic particles, and microplates were obtained, respectively. Based on the experimental results, the effect of lead source was simply discussed.

Sign in / Sign up

Export Citation Format

Share Document