Solvothermal Synthesis and Luminescence Properties of Gd2O2S:RE3+ (RE3+=Eu3+/Tb3+) Hollow Sphere

2019 ◽  
Vol 807 ◽  
pp. 1-10 ◽  
Author(s):  
Guang Xi Xu ◽  
Xiao Tong Sang ◽  
Jing Bao Lian ◽  
Nian Chu Wu ◽  
Xue Zhang
Keyword(s):  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Raw Materials ◽  
Hollow Spheres ◽  
Hollow Structure ◽  
Molar Ratio ◽  
Detailed Characterization ◽  
X Ray ◽  
Electronic Microscope

Eu3+ and Tb3+ ions singly activated Gd2O2S hollow spheres have been successfully synthesized via solvothermal method by using Gd (NO3)3, Eu (NO3)3, Tb (NO3)3 and thiourea as raw materials. Detailed characterization of the as-prepared samples were obtained by X-ray diffractometry (XRD), field emission scanning electron microscopy (FE-SEM), transmission electronic microscope (TEM) and photoluminescence (PL) spectroscopy. The results demonstrate that at 220 oC for 24 h, the molar ratio of thiourea/Gd3+ has no significant impact on the phase composition of Gd2O2S products. With the reaction time increased from 6 h to 24 h, the morphology of Gd2O2S samples changed from ellipsoidal to near-spheroidal structure, but still remained hollow structure. PL results show that the strongest emission peaks for Gd2O2S:Eu3+ and Gd2O2S:Tb3+ samples were centered at 625 nm and 545 nm, corresponding to the 5D0→7F2 transition of Eu3+ ions and 5D4→7F5 transition of Tb3+ ions, respectively. The quenching concentrations for Eu3+ and Tb3+ ions were 12% and 6%, which can be attributed to the exchange interaction for Eu3+ and Tb3+ ions, respectively.

Solvothermal Synthesis of Bi2Se3 Hexagonal Nanosheet Crystals

2011 ◽  
Vol 236-238 ◽  
pp. 1712-1716 ◽  
Author(s):  
Hai Tao Liu ◽  
Jun Dai ◽  
Jia Jia Zhang ◽  
Wei Dong Xiang
Keyword(s):  
Electron Microscope ◽  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
Uniform Size ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Scanning Electron

Bismuth selenide (Bi2Se3) hexagonal nanosheet crystals with uniform size were successfully prepared via a solvothermal method at 160°C for 22 h using bismuth trichloride(BiCl3) and selenium powder(Se) as raw materials, sodium bisulfite(NaHSO3) as a reducing agent, diethylene glycol(DEG) as solvent, and ammonia as pH regulator. Various techniques such as X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), and selected area electron diffraction (SAED) were used to characterize the obtained products. Results show that the as-synthesized samples are pure Bi2Se3 hexagonal nanosheet crystals. A possible growth mechanism for Bi2Se3 hexagonal nanosheet crystals is also discussed based on the experiment.

Synthesis and Characterization of Zn-Ca-Mg-Al Hydrotacite-Like Compounds and its Application in the PVC

2011 ◽  
Vol 66-68 ◽  
pp. 65-69
Author(s):  
Long Feng Li ◽  
Yuan Gao ◽  
Mao Lin Zhang
Keyword(s):  
Reaction Time ◽  
Ph Value ◽  
Raw Materials ◽  
Treatment Temperature ◽  
Molar Ratio ◽  
Medium Ph ◽  
X Ray ◽  
Ft Ir ◽  
Thermal Stability Of

Ca-Mg-Al hydrotalcite-like compounds (CaMgAl-HTLcs) were synthesized by a hydrothermal method, and characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and differential thermal analysis (DTA) techniques. The effects of the medium pH value, the molar ratio of the raw materials, the reaction temperature and the reaction time on the structure of CaMgAl-HTLcs were studied. The results showed that increasing treatment temperature and reaction time could improve the crystallinity and monodispersity of hydrotalcite-like compound particles. And well-defined CaMgAl-HTLcs could be prepared at a pH value of 10~11 with n(Zn+Mg+Ca):n(Al) =2. The products synthesized were applied to PVC to improve the thermal stability of PVC.

Sintering and Characterization of Calcium Phosphate Biomaterials Elaborated from Fossilized Calcareous Shell

2014 ◽  
Vol 936 ◽  
pp. 701-706
Author(s):  
Daiara F. Silva ◽  
Nelson Heriberto Almeida Camargo ◽  
Nelson Levandowski ◽  
Priscila F. Franczak ◽  
Mônica S. Schneider
Keyword(s):  
Calcium Phosphate ◽  
Open Porosity ◽  
Raw Materials ◽  
Microstructural Characterization ◽  
Bone Substitutes ◽  
Molar Ratio ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Bioceramics of calcium phosphate, obtained from natural raw materials, are promising as bone substitutes because they exhibit crystallographic similarity with the bone tissue. This work deals with the sintering and characterization of calcium phosphate biomaterials from fossilized calcareous shells. Four compositions of biomaterials were prepared with Ca/P molar ratio ranging from 1.4 to 1.67. They were synthesized using a wet method and calcined at 900°C/2h providing calcium phosphate powder, then compressed into a metallic mould. The samples obtained from this compression were sintered at 1200oC for 2h. The biomaterials recovered from sintering were subjected to a microstructural characterization by scanning electron microscopy [SE and by X-ray diffraction [XR. Mechanical properties were determined by compression tests. Finally, the Arthur method was used for determining the hydrostatic density and open porosity from these biomaterials. The value of fracture strength was between 54 and 84 MPa for compositions 1.5, 1.67 and 1.6 molar and for composition 1.4 molar about 328 Mpa. The results also showed was the amount of open porosity which ranged between 35 and 54% with increasing Ca/P molar ratio. These studies demonstrate that the production of biomaterials from fossilized calcareous shells may be a new alternative to the production of biomaterials for bone reconstruction.

Hydrothermal Synthesis and Characterization of Ca-Mg-Al Hydrotacite-Like Compounds

2011 ◽  
Vol 287-290 ◽  
pp. 569-572 ◽  
Author(s):  
Mao Lin Zhang ◽  
Yuan Gao ◽  
Long Feng Li
Keyword(s):  
Reaction Time ◽  
Ph Value ◽  
Raw Materials ◽  
Treatment Temperature ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Medium Ph ◽  
X Ray ◽  
Ft Ir

Ca-Mg-Al hydrotalcite-like compounds (CaMgAl-HTLcs) were synthesized by a hydrothermal method, and characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and differential thermal analysis (DTA) techniques. The effects of the medium pH value, the molar ratio of the raw materials, the reaction temperature and the reaction time on the structure of CaMgAl-HTLcs were studied. The results showed that increasing treatment temperature and reaction time could improve the crystallinity and monodispersity of hydrotalcite-like compound particles. And well-defined CaMgAl-HTLcs could be prepared at a pH value of 10~11 with n (Mg+Ca): n (Al) = 1~3 and n (Mg): n (Ca) = 1~3.

Solvothermal Synthesis and Characterization of Zn(NH3)CO3 Single Crystal

2004 ◽  
Vol 817 ◽  
Author(s):  
Fushan Wen ◽  
Jiesheng Chen ◽  
Jin Hyeok Kim ◽  
Taeun Kim ◽  
Wenlian Li
Keyword(s):  
Solvothermal Synthesis ◽  
Room Temperature ◽  
Raw Materials ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Photoluminescent Property ◽  
X Ray ◽  
3 Dimensional ◽  
Zinc Carbonate

AbstractA new 3-dimensional zinc carbonate Zn(NH3)CO3 has been synthesized from a glycol system with urea and zinc acetate as raw materials. The crystal structure and photoluminescent properties have been investigated using X-ray diffraction, smart CCD and FL. The compound had an orthorhombic system with space group of Pna21 with M = 142.41, a = 9.1449(18) Å, b = 7.5963(15) Å, c = 5.4982(11) Å, V = 381.95(13) Å3, Z = 4, R = 0.0285 and RW = 0.0745. The NH3 and CO32- were connected through the Zn-N bond and Zn-O bond in the symmetric unit. Photoluminescent property was observed in the compound at room temperature and the exited and emission peaks were located at about 350 nm and 426 nm, respectively.

CuS Nanotubes:Microwave-Solvothermal Synthesis and Photocatalytic Property

2012 ◽  
Vol 554-556 ◽  
pp. 605-609 ◽  
Author(s):  
Xiao Lin Liu ◽  
Ying Jie Zhu ◽  
Bin Yang ◽  
Qian Zhang ◽  
Zhi Feng Li
Keyword(s):  
Electron Microscopy ◽  
Copper Sulfide ◽  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Raw Materials ◽  
Low Cost ◽  
Photocatalytic Property ◽  
X Ray ◽  
Microwave Assisted ◽  
Transmission Electron

Copper sulfide (CuS) nanotubes assembled by nanoparticles were successfully synthesized by reaction thiourea with Cu(OH)2nanowire precursor which was obtained using CuCl2and NaOH as raw materials in the solvent ethylene glycol at 80 °C by a facile microwave-assisted solvothermal method. The forming influencing factors of CuS nanotubes were investigated. One of the advantages of this method is that the preparation of CuS nanotubes can well duplicate the shape of the nanowire precursor, thus the simplicity and low cost can be achieved. The products are characterized by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). The photocatalytic property of the CuS samples was also investigated.

Preparation of hollow Fe3O4 spheres through a facile method and their applications

2017 ◽  
Vol 10 (06) ◽  
pp. 1750075 ◽  
Author(s):  
Xingping Wu ◽  
Aiping Zhu ◽  
Zhaodong Nan
Keyword(s):  
Saturation Magnetization ◽  
Ostwald Ripening ◽  
Solvothermal Method ◽  
Hollow Spheres ◽  
Hollow Structure ◽  
Solid Sphere ◽  
Small Particles ◽  
Potential Applications ◽  
One Step ◽  
Solid Spheres

Fe3O4 hollow microspheres with good dispersibility and high saturation magnetization were synthesized through a facile one-step solvothermal method. The formation mechanism of the hollow structure was studied by taking time-dependent experiments. Porous [Formula: see text]-FeOOH and [Formula: see text]-Fe2O3 nanosheets were firstly fabricated. Fe3O4 solid spheres aggregated by small particles were obtained from the transition of [Formula: see text]-FeOOH and [Formula: see text]-Fe2O3. Finally, the solid sphere is transferred to hollow sphere through Ostwald ripening. The maximum saturation magnetization of the hollow spheres is [Formula: see text][Formula: see text]emu/g, which is higher than some results reported in references. The Fe3O4 hollow spheres show potential applications in microwave absorption and photocatalysis.

Low-temperature route to nanoscale P3N5 hollow spheres

2003 ◽  
Vol 18 (10) ◽  
pp. 2359-2363 ◽  
Author(s):  
Hongzhou Gu ◽  
Yunle Gu ◽  
Zhefeng Li ◽  
Yongcheng Ying ◽  
Yitai Qian
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hollow Spheres ◽  
Molar Ratio ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Influence Of Temperature On ◽  
Wide Gap ◽  
20 Nm ◽  
High Degree

Nanoscale hollow spheres of amorphous phosphorus nitride (P3N5) were synthesized by reacting PCl3 with NaN3 at 150–250 °C. Transmission electron microscope images show that the hollow spheres have a diameter of 150–350 nm, and the thickness of the shell is 20 nm. A very small amount of curly films were also found in the sample prepared at 150 °C. The infrared spectrum indicates a high degree of purity. X-ray photoelectron spectroscopy indicates the presence of P and N, with a molar ratio of 1:1.62 for P:N. Ultraviolet-visible absorption spectroscopy shows an absorption band at 265–315 nm. Under photoluminescent excitation at 230 nm, the P3N5 emits ultraviolet light at 305 nm. With a band gap of 4.28 eV, the products may be a wide gap semiconductor. A possible mechanism and the influence of temperature on the formation of the hollow spheres are also discussed.

Solvothermal synthesis and characterization of well-dispersed cerium-doped Y2SiO5 phosphor particles

2021 ◽  
Vol 112 (10) ◽  
pp. 812-816
Author(s):  
Xianxue Li
Keyword(s):  
Solvothermal Method ◽  
Luminescence Decay ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fluorescence Spectrophotometry ◽  
Decay Properties ◽  
Transmission Electron ◽  
Water As Solvent ◽  
Pure Phase

Abstract Well-dispersed cerium-doped Y2SiO5 (Ce:YSO) phosphor particles with spherical morphology and good luminescence intensity have been achieved by a solvothermal method with ethanol and water as solvent media. X-ray diffraction, Fourier transform infrared spectroscopy, fluorescence spectrophotometry and transmission electron microscopy were employed to characterize the as-synthesized Ce:YSO precursor and powders. The results showed that pure-phase Ce:YSO powders with a mean particle size of about 162 nm were accurately available at 310°C and above. The fluorescence ability and persistent luminescence decay properties of the Ce:YSO powders were also studied, and the excellent fluorescence properties could be attributed to the homogeneous Ce:YSO particles obtained through the solvothermal method.

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