Synthesis of Lanthanum-Strontium Manganites by a Hydroxide-Precursor Co-Precipitation Method in Solution and in Reverse Micellar Microemulsion

2005 ◽  
Vol 494 ◽  
pp. 155-160 ◽  
Author(s):  
V. Uskoković ◽  
Darko Makovec ◽  
Miha Drofenik

Nanostructured lanthanum-strontium manganites have been synthesized using two different co-precipitation approaches, one in bulk solution, and the other in reverse micelles of CTAB/1-hexanol/1-butanol/water microemulsion. In both cases, precursor cations were precipitated by alkali precipitating agents. The properties of the material synthesized by using these two methods were compared in order to reveal potential advantages of microemulsion-assisted approach. The influence of the annealing conditions on the properties of synthesized manganites was investigated by using X-ray diffraction, transmission electron microscopy, differential thermal analysis, thermogravimetric analysis and magnetic measurements.

2011 ◽  
Vol 311-313 ◽  
pp. 1713-1716 ◽  
Author(s):  
Yan Rong Sun ◽  
Tao Fan ◽  
Chang An Wang ◽  
Li Guo Ma ◽  
Feng Liu

Nano-hydroxyapatite with different morphology was synthesized by the co-precipitation method coupled with biomineralization using Ca(NO3)2•4H2O and (NH4)2HPO4 as reagents, adding chondroitin sulfate, agarose and aspartic acid as template. The structure and morphology of the prepared powders were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM).


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.


2007 ◽  
Vol 280-283 ◽  
pp. 521-524
Author(s):  
Li Qiong An ◽  
Jian Zhang ◽  
Min Liu ◽  
Sheng Wu Wang

Yb3+ and Ho3+ co-doped Lu2O3 nanocrystalline powders were synthesized by a reversestrike co-precipitation method. The as-prepared powders were examined by the X-ray diffraction and transmission electron microscopy. The phase composition of the powders was cubic and the particle size was in the range of 30~50 nm. Emission and excitation spectra of the powders were measured by a spectrofluorometer and the possible upconversion luminescence mechanism was also discussed.


2014 ◽  
Vol 1053 ◽  
pp. 444-449
Author(s):  
Xue Wen Cui ◽  
Gang Cheng ◽  
Rui Jiang Liu ◽  
Li Wei Wang ◽  
Yan Shuai Wang

The magnetic Fe2O3 nanoparticles were prepared by co-precipitation method with FeCl3 and NaOH as starting reagents. The surface of Fe2O3 nanoparticles was modified with tetraethyl orthosilicate. Fe2O3@SiO2 nanocomposites were calcined at 600 °C. The nanocomposites were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). The PLL-Fe2O3@SiO2 (SMNP) was prepared by modifying with poly-L-lysine on the surface. The SMNP combined with plasmid siRNA by static electrical charges as one of gene carriers was transfected into SD rat neurons. The results of fluorescence microscope and Prussian blue staining show that SMNP can effectively enter cells. Therefore, SMNP are one kind of novel and effective gene carriers, it can transfect the plasmid which carries the siRNA into SD rats neurons in vitro.


2014 ◽  
Vol 879 ◽  
pp. 155-163 ◽  
Author(s):  
Rahizana Mohd Ibrahim ◽  
Markom Masturah ◽  
Huda Abdullah

Nanoparticles of Zn1-xFexS ( x=0.0,0.1,0.2 and 0.3) were prepared by chemical co-precipitation method from homogenous solution of zinc and ferum salt at room temperature with controlled parameter. These nanoparticles were sterically stabilized using Sodium Hexamethaphospate (SHMP). Here, a study of the effect of Fe doping on structure, morphological and optical properties of nanoparticles was undertaken. Elemental analysis, morphological and optical properties have been investigated by Fourier-Transform-Infrared spectroscopy (FT-IR), X-Ray Fluorescence (XRF), Field Emmision Scanning Electron Microscopy (FESEM), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and UV-Visible Spectroscopy. FTIR measurement confirmed the presence of SHMP in the nanoparticles structure with the FESEM images depicting considerable less agglomeration of particles with the presence of SHMP. While XRF results confirm the presence of Fe2+ ion as prepared in the experiment. The particles sizes of the nanoparticles lay in the range of 2-10 nm obtained from the TEM image were in agreement with the XRD results. The absorption edge shifted to lower wavelengths with an increase in Fe concentration shown in the UV-Vis spectroscopy. The band gap energy value was in the range of 4.95 5.15 eV. The blueshift is attributed to the quantum confinement effect.


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.


2011 ◽  
Vol 347-353 ◽  
pp. 1416-1419
Author(s):  
You Ning Xu ◽  
Hai Zhao ◽  
Duo Jiao Guan

Fe-Mn-Ce metal oxides nanosized particles have been prepared by co-precipitation approach using three kinds of precipitants NaOH, NH4OH and Na2CO3. The products were characterized by Powder X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and BET study. It was found that the samples prepared with NH4OH as a precipitator show higher surface areas and larger sulfur capacity at low calcinations temperature. At high reaction temperatures, the samples prepared with Na2CO3 as precipitator exhibited much better activities for SCR of nitric oxide with ammonia than catalysts prepared with NH4OH and NaOH as the precipitants.


2012 ◽  
Vol 271-272 ◽  
pp. 320-323
Author(s):  
Xiao Chun Ma ◽  
Lei Hao Cui ◽  
Guang Fei Xu

In this paper, the Fe3O4 magnetic nanometer particle was prepared by co-precipitation method. At the same time, the samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the surface active agent (PEG4000) can be good for the dispersion performance of Fe3O4 magnetic nanometer particle; and the temperature of 80°C is the appropriate drying temperature to prepare the Fe3O4 magnetic nanometer particle.


Author(s):  
Fengfeng Li ◽  
Mingxi Zhang ◽  
Jin Wang ◽  
Yongfeng Cai ◽  
Dushao Zhao ◽  
...  

Abstract In this work, we fabricate a highly efficient photocatalytic AgBr/Ag2CO3 heterojunction through the co-precipitation method. The obtained samples were characterized by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, ultraviolet-visible diffuse reflectance spectra and X-ray photoelectron spectroscopy. The photocatalytic activities of obtained samples can be assessed by visible light (λ ≥ 400 nm) degradation of rhodamine B solution. X-ray diffraction revealed that the crystallinity of the AgBr/Ag2CO3heterojunction was significantly higher than pure AgBr and Ag2CO3. Moreover, the AgBr/ Ag2CO3 heterojunction prepared at pH = 6 has the best photocatalytic performance, it can raise the degradation degree of rhodamine B over 95% at 20 min. Finally, a possible photocatalytic mechanism is discussed.


2008 ◽  
Vol 8 (3) ◽  
pp. 1211-1213 ◽  
Author(s):  
Luo Jun-Ming ◽  
Li Yong-Xiu ◽  
Deng Li-Ping ◽  
Yuan Yong-Rui ◽  
Chen Wei-Fan

Y2O3 nanoparticles doped with different concentrations of Er3+ were prepared by the co-precipitation method. X-ray diffraction and transmission electron microscopy results show that Er3+ dissolves completely in the Y2O3 cubic phase. The Er3+:Y2O3 nanoparticles are homogeneous in size and nearly spherical, and the average diameter of the particles after being calcined at 1,000 °C for 2 h is in the range of 40–60 nm. When Er3+:Y2O3 nanoparticles are excited under a 980 nm diode laser, there are two main emission bands: green emission centered at 562 nm corresponding to the 4S3/2/2H11/2 → 4I15/2 radiative transitions and red emission centered at 660 nm corresponding to the 4F9/2 ∼ 4I15/2 radiative transitions. By changing the doping concentration of Er3+ ions, the up-conversion luminescence can be gradually tuned from green to red.


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