Selected-Control Solvothermal Synthesis of Nanoscale Hollow Spheres and Single-Crystal Tubes of PbTe

2004 ◽  
Vol 2004 (22) ◽  
pp. 4521-4524 ◽  
Author(s):  
Guifu Zou ◽  
Zhaopin Liu ◽  
Debao Wang ◽  
Changlong Jiang ◽  
Yitai Qian
Keyword(s):  
Single Crystal ◽  
Solvothermal Synthesis ◽  
Hollow Spheres

Solvothermal Synthesis of Single-Crystal Magnetite Hollow Sub-Microspheres: A Novel Formation Mechanism and Magnetic Properties

2016 ◽  
Vol 69 (7) ◽  
pp. 798
Author(s):  
Gongqin Yan ◽  
Guanlin Zhao ◽  
Fei He
Keyword(s):  
Magnetic Properties ◽  
Single Crystal ◽  
Formation Mechanism ◽  
Solvothermal Synthesis ◽  
Shell Thickness ◽  
Ostwald Ripening ◽  
Hollow Spheres ◽  
Diameter Distribution ◽  
Key Factor ◽  
Different Diameters

In this paper, single-crystal magnetite hollow sub-microspheres with a narrow diameter distribution are synthesized through a simple solvothermal process in ethylene glycol in the presence of urea and a small amount of water. The determining role of water in the solvothermal synthesis is studied. It is found that a small amount of water is crucial for the formation of the magnetite hollow spheres. A novel formation mechanism of the magnetite hollow spheres is proposed based on the bubble-assisted Ostwald ripening. It is believed that the appropriate amount of CO2 gas bubbles produced in situ by urea hydrolysis is crucial for the formation of hollow spheres. Because of the existence of gas microbubbles, magnetite solid spheres with a loose core and compact shell form, which is the key factor for the following inside-out Ostwald ripening and the formation of the hollow spheres. Thus, by simple changing of the water dosage, magnetite hollow spheres with different diameters and shell thicknesses are obtained controllably. The magnetic properties of the obtained magnetite hollow spheres are studied. It is found that the saturation magnetization of the magnetite hollow sub-microspheres decreases with the increasing shell thickness, whereas the coercivity and remanent magnetization increase with increasing shell thickness.

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 CoFe2O4 hollow spheres

2007 ◽  
Vol 42 (24) ◽  
pp. 10113-10117 ◽  
Author(s):  
Qi Liu ◽  
Lifang Lai ◽  
Xiujuan Fu ◽  
Fangping Zhu ◽  
Jianhua Sun ◽  
...  
Keyword(s):  
Solvothermal Synthesis ◽  
Hollow Spheres

Magnetic Ni and Ni/Pt hollow nanospheres and their catalytic activities for hydrolysis of ammonia borane

2014 ◽  
Vol 2 (43) ◽  
pp. 18171-18176 ◽  
Author(s):  
Wenliang Jiao ◽  
Xiaopeng Hu ◽  
Hao Ren ◽  
Pengfei Xu ◽  
Ranbo Yu ◽  
...  
Keyword(s):  
Solvothermal Synthesis ◽  
Hollow Spheres ◽  
Ammonia Borane ◽  
Hollow Nanospheres ◽  
Catalytic Activities ◽  
Pt Hollow Nanospheres ◽  
Hydrolysis Of ◽  
Inside Out

The controllable solvothermal synthesis of hollow nickel nanospheres was achieved via an assembly-then-inside-out evacuation process. The Ni/Pt hollow spheres exhibit high catalytic activities for the hydrolysis of ammonia borane.

ChemInform Abstract: A Rapid Solvothermal Synthesis of Cerium Oxide Hollow Spheres and Characterization.

ChemInform ◽  
2012 ◽  
Vol 43 (48) ◽  
pp. no-no
Author(s):  
Murukanahally Kempaiah Devaraju ◽  
Xiangwen Liu ◽  
Shu Yin ◽  
Tsugio Sato
Keyword(s):  
Cerium Oxide ◽  
Solvothermal Synthesis ◽  
Hollow Spheres

A rapid solvothermal synthesis of cerium oxide hollow spheres and characterization

2012 ◽  
Vol 194 ◽  
pp. 43-47 ◽  
Author(s):  
Murukanahally Kempaiah Devaraju ◽  
Xiangwen Liu ◽  
Shu Yin ◽  
Tsugio Sato
Keyword(s):  
Cerium Oxide ◽  
Solvothermal Synthesis ◽  
Hollow Spheres
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