scholarly journals Direct Fabrication of Cobalt Oxide Nanoparticles Employing Sucrose as a Combustion Fuel

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
M. Th. Makhlouf ◽  
B. M. Abu-Zied ◽  
T. H. Mansoure

Combustion method has been used as a fast and facile method to prepare nanocrystalline Co3O4 spinel employing sucrose as a combustion fuel. The products were characterized by thermal analyses (TGA and DTA), X-ray diffraction technique (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. Experimental results revealed that the molar ratio of fuel/oxidizer (F/O) plays an important role in controlling the crystallite size of Co3O4 nanoparticles. Transmission electron microscopy indicated that the crystallite size of Co3O4 nanocrystals was in the range of 13–32 nm. X-ray diffraction confirmed the formation of CoO phase with spinel Co3O4. The effect of calcination temperature on crystallite size and morphology has been, also, discussed.

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Celia Marcos ◽  
María de Uribe-Zorita ◽  
Pedro Álvarez-Lloret ◽  
Alaa Adawy ◽  
Patricia Fernández ◽  
...  

Chert samples from different coastal and inland outcrops in the Eastern Asturias (Spain) were mineralogically investigated for the first time for archaeological purposes. X-ray diffraction, X-ray fluorescence, transmission electron microscopy, infrared and Raman spectroscopy and total organic carbon techniques were used. The low content of moganite, since its detection by X-ray diffraction is practically imperceptible, and the crystallite size (over 1000 Å) of the quartz in these cherts would be indicative of its maturity and could potentially be used for dating chert-tools recovered from archaeological sites. Also, this information can constitute essential data to differentiate the cherts and compare them with those used in archaeological tools. However, neither composition nor crystallite size would allow distinguishing between coastal and inland chert outcrops belonging to the same geological formations.


2017 ◽  
Vol 727 ◽  
pp. 395-402
Author(s):  
Zi Run Wang ◽  
Xin Liu ◽  
Gui Qi Xie ◽  
Yi Wu ◽  
Ming Nie ◽  
...  

Cu-Ag alloy nanoparticles were synthesized by a liquid phase reduction method. Using sodium formaldehyde sulfoxylate (SFS) as reducing agents, copper-silver bimetallic nanoleaflets with high content of Cu were prepared. The obtained Cu-Ag bimetallic nanocrystal were characterized by powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscope (FESEM), high resolution transmission electron microscopy (HRTEM) and transmission electron microscopy (TEM). Different molar ratio of Cu-Ag bimetallic nanomaterials could produce different morphologies. The surfactant β-CD plays a crucial role on the structure of the products. The different molar ratios of Cu-Ag were also investigated. The electrochemical activity was evaluated using cyclic voltammetry (CV), electrochemical hydrogen evolution reaction (HER) in a 0.5M Na2SO4 electrolyte.


2010 ◽  
Vol 123-125 ◽  
pp. 631-634 ◽  
Author(s):  
Yu Ping Tong ◽  
Shun Bo Zhao ◽  
Feng Lan Li ◽  
Chang Yong Li

La1.6Ln0.4Zr2O7 (Ln= La, Nd, Dy, Er) nanocrystals were prepared by stearic acid combustion method. The samples were characterized by powder X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) nitrogen adsorption, transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The photocatalytic activity of La1.6Ln0.4Zr2O7 was evaluated by the photocatalytic degradation of methyl orange. The order of the photocatalytic activity was as following: La1.6Er0.4Zr2O7>La1.6Dy0.4Zr2O7> La1.6Nd0.4Zr2O7> La2Zr2O7. La1.6Dy0.4Zr2O7 showed that the best photocatalytic activity and the reason may be related to the big magnetic moment of Er3+. It may be considered largely to be caused by the partly occupied Ln4f levels. Since the solid samples have the same structure, the reason that La1.6Er0.4Zr2O7 shows the highest reactivity may be related to lowest Ln4f level of Er3+.


2012 ◽  
Vol 1481 ◽  
pp. 127-133
Author(s):  
A. Medina ◽  
L. Béjar ◽  
G. Herrera-Pérez

ABSTRACTZinc oxide (ZnO) nanoparticles were produced using chemical precipitation synthesis with a molar ratio of 1:1, 1:2 and 1:3. The structure, chemical composition and morphology were investigated by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). XRD and EDS demonstrated that the all particles formed at different atomic proportion were of wurtzite crystal structure with the same chemical composition. SEM and TEM showed the formation of hexagonal particles with a molar ratio of 1:1 while the samples synthesized with a molar ratio 1:2 and 1:3 showed a circular shape. HRTEM and Fast Fourier Transform (FFT) demonstrated that the all particles were formed with a preferable [0001] growth direction.


2007 ◽  
Vol 336-338 ◽  
pp. 2037-2040
Author(s):  
Moon Hee Choi ◽  
Yoon Bok Lee ◽  
In Bae Kim ◽  
Young Seok Kim ◽  
Young Mok Rhyim ◽  
...  

Cadmium selenide (CdSe) of hollow sphere with 30-50nm in diameter have been prepared form the mixed solution of cadmium chloride (CdCl2), sodium selenosulfate(Na2SeSO3) and ethylenediamine (H2NCH2CH2NH2) at room temperature. The hollow sphere of CdSe was characterized by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The molar ratio of EDA to Cd2+ ions in this system was important factor on controlled synthesis in the self-encapsulated morphology. Based on the observation on morphological difference with molar ratio of EDA to Cd2+ ion, the possible mechanism for the formation of CdSe hollow sphere was discussed.


2009 ◽  
Vol 08 (03) ◽  
pp. 273-276 ◽  
Author(s):  
MASOUD SALAVATI-NIASARI ◽  
FATEMEH DAVAR

Co and Co3O4 nanoparticles are synthesized via a thermal decomposition method in the presence of oleylamine using a new precursor of [Bis(2-hydroxyacetophenato)cobalt(II)]. The products were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The hysteresis loops of the obtained samples reveal the ferromagnetic behaviors of the enhanced coercivity (Hc) and decreased saturation magnetization (Ms) in contrast to their respective bulk materials.


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.


Author(s):  
Eric O'Quinn ◽  
Cameron Tracy ◽  
William F. Cureton ◽  
Ritesh Sachan ◽  
Joerg C. Neuefeind ◽  
...  

Er2Sn2O7 pyrochlore was irradiated with swift heavy Au ions (2.2 GeV), and the induced structural modifications were systematically examined using complementary characterization techniques including transmission electron microscopy (TEM), X-ray diffraction...


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.


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