Preparation and Characterization of Pr-CeO2 Nano-Powders by Co-Precipitation-Hydrothermal Method

2008 ◽  
Vol 368-372 ◽  
pp. 781-783
Author(s):  
Zhen Feng Zhu ◽  
Jing Ping Li ◽  
Jun Yang

Pr-CeO2 nano-size powders with the average crystallites size of 12 nm and particle size of 18 nm were prepared by a co-precipitation-hydrothermal method using Ce(NO3)3·6H2O, Pr6O11 as raw materials and ammonia as the precipitation agent. The influence of hydrothermal treatment time, hydrothermal treatment temperature on the average crystallites size, color of powders and the solubility of praseodymium were investigated. The synthesized powders were characterized by X-ray diffraction, transmission electron microscopy and color measurements. Results showed that after calcining at 800°C for 4 hours, the color of the as-prepared powder changes from light red to red brown, the solubility of praseodymium and the crystallites size of the Pr-CeO2 powder both increase.

2017 ◽  
Vol 889 ◽  
pp. 229-233
Author(s):  
Nur Arifah Ismail ◽  
Mohd Hasmizam Razali ◽  
Khairul Anuar ◽  
Mat Amin

In this research, the effect of different hydrothermal treatment temperature (100, 150, and 200 °C) on the products obtained by hydrothermal method was studied. Various characterization techniques was carried out such as X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy dispersive of x-ray spectroscopy (EDX) and fourier transform infrared spectroscopy (FTIR). XRD analysis shows that titanate phase was formed at 150 and 200 °C hydrothermal treatment. On the other hand, at 100 °C anatase TiO2 phase structured was gained which is similar with the TiO2 precursor. Morphological study using FESEM revealed that nanofibers and nanorods samples obtained at 150 °C and 200 °C, respectively. At 100°C, irregular shaped particle was attained similar with TiO2 precursors. FTIR spectra for the all studied sample displayed three main broad peaks at the range of 3700-2800, and 1800-1400 assigned to –OH stretching and deformation mode due to H2O molecules and M-O stretching mode at 900-400 cm-1 assigned to Ti-O bond.


1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.


MRS Advances ◽  
2017 ◽  
Vol 2 (64) ◽  
pp. 4025-4030 ◽  
Author(s):  
T. Kryshtab ◽  
H. A. Calderon ◽  
A. Kryvko

ABSTRACTThe microstructure of Ni-Mg-Al mixed oxides obtained by thermal decomposition of hydrotalcite-like compounds synthesized by a co-precipitation method has been studied by using X-ray diffraction (XRD) and atomic resolution transmission electron microscopy (TEM). XRD patterns revealed the formation of NixMg1-xO (x=0÷1), α-Al2O3 and traces of MgAl2O4 and NiAl2O4 phases. The peaks profile analysis indicated a small grain size, microdeformations and partial overlapping of peaks due to phases with different, but similar interplanar spacings. The microdeformations point out the presence of dislocations and the peaks shift associated with the presence of excess vacancies. The use of atomic resolution TEM made it possible to identify the phases, directly observe dislocations and demonstrate the vacancies excess. Atomic resolution TEM is achieved by applying an Exit Wave Reconstruction procedure with 40 low dose images taken at different defocus. The current results suggest that vacancies of metals are predominant in MgO (NiO) crystals and that vacancies of Oxygen are predominant in Al2O3 crystals.


2014 ◽  
Vol 70 (6) ◽  
pp. 1004-1010 ◽  
Author(s):  
Th. I. Shalaby ◽  
N. M. Fikrt ◽  
M. M. Mohamed ◽  
M. F. El Kady

This study investigated the applicability of magnetite Fe3O4 nanoparticles coated with chitosan (CMNs) for the removal of some toxic heavy metals from simulated wastewater. Magnetic nanomaterials were synthesized using the co-precipitation method and characterized by transmission electron microscope, scanning electron microscope, X-ray diffraction, and Fourier transformer infrared spectroscopy. The magnetic properties of the prepared magnetic nanoparticles were determined by a vibrating-sample magnetometer. Batch experiments were carried out to determine the adsorption kinetics of Cr(VI) and Cd(II) by magnetic nanoparticles. It is noteworthy that CMNs show a highly efficient adsorption capacity for low concentration Cr(VI) and Cd(II) ions solution, which can reach 98% within 10 min.


2016 ◽  
Vol 25 (6) ◽  
pp. 096369351602500 ◽  
Author(s):  
Ruimin Fu ◽  
Mingfu Zhu

Nowadays, the hummers method for preparation of graphene oxide (GO) was improved. The grapheme oxide @ Fe3O4 magnetic nanocomposites were synthesized by co-precipitation method. After analysing the morphology and structure of obtained nanocomposites by X-ray diffraction (XRD), transmission electron microscope (TEM) and Fourier transform infrared (FT-IR) spectroscopy, the result was shown as follows. The particle size of Fe3O4 in nanocomposites is 30 nm. Many functional groups are found in grapheme oxide, and such groups could be used to bind with the drug. In the test for magnetic properties, the nanocomposites gathered rapidly in the vicinity of the permanent magnet. The nanocomposites, with high superparamagnetism, can be used in the following applications: drug targeting transports, drug carrier, and diagnosis assistant system.


Nukleonika ◽  
2017 ◽  
Vol 62 (2) ◽  
pp. 73-77 ◽  
Author(s):  
Zbigniew Surowiec ◽  
Mieczysław Budzyński ◽  
Katarzyna Durak ◽  
Grzegorz Czernel

Abstract Small particles of magnetite, i.e. 7.5, 13.4 and 14.1 nm in diameter, were obtained by the method of co-precipitation. The crystal structure and size distributions were determined by means of transmission electron microscopy and X-ray diffraction. The magnetic properties of the nanoparticles were tested by Mössbauer spectroscopy within the temperature range from 3 K to room temperature (RT). The Mössbauer study of magnetic nanoparticles reveals relaxation behaviour related to the existence of the superparamagnetic phase. The blocking temperature depends on the sizes of the nanoparticles and the ammonia concentration.


2012 ◽  
Vol 624 ◽  
pp. 59-62 ◽  
Author(s):  
Cai Xia Li ◽  
Jun Guo ◽  
Danyu Jiang ◽  
Qiang Li

In this paper, employing Cu(AC)2•H2O, SnCl2•2H2O and thiourea as raw materials, the composites of graphene/Cu2SnS3 quantum dots (QDs) were prepared simply and quickly using the hydrothermal method. Meanwhile, the separate Cu2SnS3 QDs were also synthesized in the same way. The as-obtained Cu2SnS3 QDs and composites’ phase structures were analyzed and characterized by powder X-ray diffraction (XRD), and the results indicated that the size of the Cu2SnS3 QDs in the composites were less than that of the separate Cu2SnS3 QDs. At the same time, their morphologies were also observed and cross-confirmed by Transmission Electron Microscopy (TEM), and the measurements manifested that Cu2SnS3 QDs were uniformly dispersed on the surface of the graphene, while the separate Cu2SnS3 QDs have obvious glomeration. In addition to this, elemental analysis was also made to verify the existence of Cu2SnS3 on the surface of graphene.


2021 ◽  
Author(s):  
liu zhenjie ◽  
Yudai Huang ◽  
xingchao Wang ◽  
Yue Zhang ◽  
juan Ding ◽  
...  

Abstract Li4Ti5O12/V2O5 nanocomposites were synthesized by a one-pot co-precipitation method. The structure and morphology of the as-prepared materials were analyzed by X-ray diffraction and transmission electron microscopy. The results show that Li4Ti5O12/V2O5 composites with different nano size were successfully synthesized. The Li4Ti5O12/V2O5 sample (2 wt.% V2O5 addition of Li4Ti5O12) keep at a high discharge capacity of 169.9 mAh g− 1 after 150 cycles at 1 C. The existence of the V2O5 reduces the size of Li4Ti5O12, which improve the electrochemical activity of the sample.


2013 ◽  
Vol 423-426 ◽  
pp. 151-154
Author(s):  
Xi Sheng He ◽  
Hui Qing Peng ◽  
Jin Li ◽  
Jun Dong

Fe3O4 magnetic nanoscale water-based magnetic fluid was fabricated by co-precipitation with citric acid (CA) and polyethylene amine (PEI) as dispersant. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM) were used to investigate the samples.The modified magenetic nanoparticles (MNPs) size of about 50nm and have a saturation magnetization about 0.25emu/g.These nanoparticles can be applied to the study of genophore.


2017 ◽  
Vol 40 (1-2) ◽  
Author(s):  
Mohsen Kord ◽  
Kambiz Hedayati ◽  
Marziyeh Farhadi

AbstractIn this work, flower-like nanoparticles of lead sulfide (PbS) and metal-doped PbS nanostructures were synthesized via a simple hydrothermal method in water as a green solvent. The effect of temperature, precipitating agent and capping agent on the morphology and particle size of the products was investigated. Sugars were used as green, safe, cost-effective, and bio-compatible capping agents. The prepared products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and ultra violet-visible spectroscopy. The effect of PbS as a photocatalyst on the degradation of three different azo dyes was investigated. Acid brown, acid violet, and acid blue were totally degraded at 60 min under ultra-violet irradiation.


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