A STUDY ON A NEW SYNTHETIC METHOD OF CdS AND CdSe NANOPARTICLES AND THEIR ORGANIC/INORGANIC NANOCOMPOSITE

2002 ◽  
Vol 01 (05n06) ◽  
pp. 501-505 ◽  
Author(s):  
JU YOUNG LEE ◽  
YOUNG SOO KANG ◽  
YONG JOO KIM

Materials such as CdS and CdSe inorganic nanoparticles have photoluminescence. Sodium oleate has been used as effective stabilizers for the synthesis of CdS and CdSe nanoparticles in water by autoclave method. Photoluminescence of CdS and CdSe with particle size of 5–14 nm showed λ max at 520 nm and 600 nm, respectively, when were excited at 365 nm. These nanoparticles doped into the PVA resulted in the organic/inorganic films ( PVA/CdS , CdSe ). Photoluminescence, X-ray diffraction and transmission electron microscopy were employed for their characterization.

2006 ◽  
Vol 05 (04n05) ◽  
pp. 663-669 ◽  
Author(s):  
GANGQIANG ZHU ◽  
HONGYAN MIAO ◽  
GUOQIANG TAN ◽  
YUN LIU ◽  
AO XIA

Potassium bismuth titanate nanoparticles were prepared by the hydrothermal method using Ti ( C 4 H 9 O )4 and Bi ( NO 3)3·5 H 2 O as raw materials in alkaline solution at temperatures of 160–200°C. The crystal phase, particle size, morphology and dispersion of the particles were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the particles with sizes of about 50–100 nm in diameter are well-dispersed K 0.5 Bi 0.5 TiO 3 (KBT) crystals of tetragonal structure, and the alkaline concentration and the temperature of solutions have great effects on the phase composition and morphology of the resultant particles. We could gain the KBT phase of high purity when the concentration of KOH is about 8–12 M and the reaction temperature is about 170–180°C.


2011 ◽  
Vol 311-313 ◽  
pp. 545-548 ◽  
Author(s):  
Yu Jiang Wang ◽  
Yong Gang Wang

NiWO4 nanoparticles were successfully synthesized by a molten salt method at 270°C. The as-prepared powders were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and exhibited a pure phase NiWO4 with about 50 nm in particle size and uniform nearly-spherical particle shape.


2004 ◽  
Vol 49 (4) ◽  
pp. 177-181 ◽  
Author(s):  
C.Y. Yun ◽  
J. Moon ◽  
K. Chung ◽  
M. Kang ◽  
C.B. Shin ◽  
...  

Photocatalytically active nanocrystalline titania particles were prepared using a hydrothermal process, by controlling the particle size and crystallinity. The crystalline structures and morphologies of the particles were characterized by X-ray diffraction and transmission electron microscopy. The BET method was used to determine the surface area and verify the grain size. To estimate the photocatalytic activity of the synthesized particles, a dye photodegradation experiment was carried out and the activity of the particles was compared with that of conventional titania. The results show that synthesized nanocrystalline titania particles had a higher photocatalytic activity than that of conventional titania. These findings provide a basis for the preparation of more effective and useful materials for use in AOP applications.


2002 ◽  
Vol 17 (9) ◽  
pp. 2197-2200 ◽  
Author(s):  
Juan Yang ◽  
Sen Mei ◽  
José M.F. Ferreira

Well-dispersed anatase and rutile nano-particles were prepared via hydrothermal treatment of tetrabutylammonium hydroxide-peptized and HNO3-peptized sols at 240 °C. A broad particle size distribution of anatase crystals was observed in the nonpeptized TiO2 species hydrothermally treated at 240 °C. X-ray diffraction and transmission electron microscopy, as well as zeta potential measurement, were used to characterize the particles. The formation of the well-dispersed anatase and rutile particles from the peptized samples could be attributed to (i) homogeneous distribution of the component in the peptized sols, and (ii) the high long-range electrostatic forces between particles in the presence of both peptizers, which were not present in the nonpeptized samples. This work provided a new way to prepare nano-crystals of titania.


2014 ◽  
Vol 887-888 ◽  
pp. 139-142
Author(s):  
Yang Rong Yao ◽  
Ying Zheng ◽  
Xu Chun Song

In the present paper, the γ-Fe2O3 nanoparticles have been successfully synthesized by the co-precipitation process and followed by calcination. The X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the as prepared nanoparticles. The results show that the phase structure of the nanoparticles is γ-Fe2O3 with the particle size ranging from 40 to 50 nm. The catalytic activity of the γ-Fe2O3 was investigated by decomposing the phenol in liquid phase. The results showed that γ-Fe2O3 has the highest catlytic activity.


2008 ◽  
Vol 368-372 ◽  
pp. 635-637
Author(s):  
Jian Feng Huang ◽  
Li Yun Cao ◽  
Jian Peng Wu ◽  
Hai Yan He

Nanocrystalline Y2BaCuO5 was prepared by a co-precipitation method with aid of ultrasonic irradiation using Y2O3, CuCl2 and BaCl2 as source materials. The crystallization and morphology of the prepared nanoparticles were characterized by X-ray diffraction and transmission electron microscopy. Results showed that Y2BaCuO5 monophase can be prepared at 900°C with NaOH + NaCO3 mixture as precipitator. Particle size of Y2BaCuO5 crystallites decreases with the increase of sonicating power. Around 30 nm Y2BaCuO5 crystallites could be achieved when sonicating power increased to 300 W.


2011 ◽  
Vol 10 (01n02) ◽  
pp. 227-231 ◽  
Author(s):  
S. S. KANMANI ◽  
N. RAJKUMAR ◽  
K. RAMACHANDRAN

TiO 2 nanoparticles and TiO 2: ZnO (80:20) nanocomposites were prepared by chemical method, and X-ray diffraction, high resolution transmission electron microscopy, and Raman analysis of the samples showed a strong anatase phase and they are further used to find and compare the particle size.


Author(s):  
R. Gronsky

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.


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