Research on Phases and Morphology of Fe-Se Powders Synthesized by Hydrothermal Method

2012 ◽  
Vol 184-185 ◽  
pp. 1171-1174
Author(s):  
Ke Gao Liu ◽  
Zhong Quan Ma ◽  
Jian Hua Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Method ◽  
Impurity Phase ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
The Poor ◽  
Transmission Electron

The Fe-Se powders have been prepared by hydrothermal method at temperatures of 160, 180 and 200 °C from FeCl3•6H2O and SeO2. The phases and morphology of the products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) respectively. Experimental results show that, the major phases of these product powders are all FeSe2, the impurity phase Se can be identified in spite of poor crystallinity of all samples. The poor crystallinity becomes seriously at lower synthesizing temperature under the experimental conditions. These product powders consist of grains, rods or flakes with sizes of 20~300nm, among which the product obtained at 180 °C has the smallest size of 20~40 nm.

Investigation on Synthesis and Morphology of SnO2 Powders Prepared by Solution Chemical Method

2012 ◽  
Vol 184-185 ◽  
pp. 1034-1037
Author(s):  
Ke Gao Liu ◽  
Zhong Quan Ma ◽  
Jian Hua Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Reaction Mechanism ◽  
Hydrothermal Method ◽  
Chemical Method ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Geometric Shapes ◽  
Transmission Electron

The SnO2 powders have been prepared by hydrothermal method at temperatures of 150, 180 °C from SnCl2•2H2O, NaOH and sulfur (S) powder. The phases and morphology of the products were analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) respectively. Experimental results show that, no impurity phases were found except SnO2 and no regular geometric shapes were observed in this product powders. The reaction mechanism is that SnO2 may be obtained by decomposition of Na2SnO2 formed from Sn(OH)2+NaOH.

Graphene-like nanostructures obtained from Biomass

2013 ◽  
Vol 1505 ◽  
Author(s):  
Gabriela Borin Barin ◽  
Yane Honorato Santos ◽  
Jennyfer Alves Rocha ◽  
Luiz Pereira da Costa ◽  
Antônio Gomes Souza Filho ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Coir Dust ◽  
Coconut Coir ◽  
Scanning Electron

ABSTRACTTwo dimensional (2D) carbon nanomaterials such as few graphite layers or graphene are extensively studied due to their unique properties suitable to be exploiting in a wide range of technological applications. Recently, the growth of high quality graphene monolayers using insects and waste as carbon precursors was reported in the literature. This methodology opened a new way to convert the waste carbon into a high-value-added product. In the present work coconut coir dust, an agroindustrial biomass, was used as biotemplate for preparing carbonaceous materials. Carbon structures were synthesized through pyrolysis under nitrogen atmosphere (100mL/min) at 500, 1000, and 1500°C during 2 hours. Starting materials were coconut coir dust in natura and coconut coir dust hydrothermally treated. The samples were characterized by X-ray diffraction, Raman Spectroscopy, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Raman spectra showed the D band for all samples, related to the presence of defects in sp2 carbon structure and G band, indicative of graphite crystallites. It was also observed that the sample carbonized at 1500°C from coconut coir dust treated by hydrothermal method showed G’ band at 2685cm-1 associated with the stacking order along the c-axis. X-ray diffraction analysis showed a broad peak around 2θ= 22° related to the presence of amorphous carbon. By increasing the pyrolysis temperature changes in XRD diffractograms were observed and the sample which was pyrolysed at 1500°C from coconut coir dust hydrothermally treated showed peaks at 2θ= 26.5°, 43° e 45° assigned to (002), (100) (101) graphite plans, respectively. Scanning electron microscopy images showed the presence of overlapping sheets and plates. Transmission Electron Microscopy (TEM) images of coconut coir dust in natura unveiled the formation of amorphous sheet. Coconut coir dust in natura and treated by the hydrothermal method pyrolysed at 1500°C, lead to the formation of some graphitic domains and few graphene layers.

Growth Mechanism and Characterization of Porous CuS Microspheres

2012 ◽  
Vol 568 ◽  
pp. 348-351
Author(s):  
Shuang Xu ◽  
Nuan Song ◽  
Chang Li Qiu ◽  
Yao Ping Zhang ◽  
Jian Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Growth Mechanism ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

In this paper, a facile method was presented to fabricate CuS porous microspheres, which were formed by the intergrowth of CuS polycrystalline nanoslices. The obtained sample has been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electronic diffraction (SAED), and scanning electron microscopy (SEM). On the basis of the experimental results, we proposed a self-assemble mechanism to elucidate the formation of CuS nanoslice structure.

Study on the Morphology and Phases of Cu-Se Powders Synthesized by Hydrothermal Co-Reduction

2010 ◽  
Vol 29-32 ◽  
pp. 1824-1827
Author(s):  
Ke Gao Liu ◽  
Bo Pang ◽  
Zhi Gang Wang ◽  
Bin Xu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Deionized Water ◽  
Experimental Results ◽  
Side Length ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Lower Temperature ◽  
Co Reduction

Cu-Se compound powders are synthesized by hydrothermal co-reduction from CuSO4•5H2O and SeO2 in deionized water at 120～200 °C. The phases and morphology of the products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) respectively. Experimental results show that, the CuSe phase can be synthesized at 120,150,180 and 200 °C, however, the purity phases become more with the temperature decreasing. It indicates that the reaction is more incomplete at lower temperature. Hexagonal flakes with side length 100～400 nm can be observed in the products at 150,180 and 200 °C, among which only the product prepared at 180 °C has the hexagonal flakes with good dispersity and homogeneous size with 200 nm length.

Study on Synthesis of Ni-S Powders Synthesized by Hydrothermal Co-Reduction

2012 ◽  
Vol 503-504 ◽  
pp. 637-640
Author(s):  
Yuan Xing Cai ◽  
Ke Gao Liu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Major Phase ◽  
X Ray ◽  
Transmission Electron ◽  
Lower Temperature ◽  
Co Reduction ◽  
Product Powder

The technologies of synthesizing Ni-S powders from 0.001 mol NiCl2•6H2O and 0.001 mol sulfur (S) powder were investigated at 95,105,120,140 and 160 °C. The phases and morphology of the products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) respectively. Experimental results show that, the Ni-S powders prepared at 120~160 °C from NiCl2•6H2O and S powder have the same major phase NiS. These products have flakes or unregular shape grains with sizes of 100~200nm. However, the product powder prepared at 105 °C has the major phase Ni3S2 without obvious impurity phases and only grains with size less than 200nm. No Nickel sulfides can be synthesized at 95 °C under the experimental conditions. It can be found that the NiS phase appears in the products powders obtained at higher temperatures while Ni3S2 obtained at lower temperature.

Sodium Nitrate Assisted Hydrothermal Synthesis of Na0.5Bi0.5TiO3 Nanoflakes

2012 ◽  
Vol 463-464 ◽  
pp. 777-780 ◽  
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
Single Crystal ◽  
Hydrothermal Method ◽  
Sodium Nitrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Single-crystal Na0.5Bi0.5TiO3 nanoflakes have been successfully synthesized at 160°C with 8M NaOH by a hydrothermal method assisted by sodium nitrate. The as-prepared samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The presence of sodium nitrate was found to play an important role in the growth of single-crystal Na0.5Bi0.5TiO3 nanoflakes.

Synthesis of Monodisperse Rod-Like Nano-AlOOH and Anti-Ultraviolet Finishing on Silk-Cotton Fabrics

2013 ◽  
Vol 796 ◽  
pp. 103-106
Author(s):  
Meng Fei Xu ◽  
Min Zheng ◽  
Zuo Shan Wang ◽  
Lian Ping Zhu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Method ◽  
Average Diameter ◽  
Cotton Fabrics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Abstract: Boehmite (AlOOH) has been prepared from AlCl3·6H2O and ammonia by a hydrothermal method. The products obtained under different conditions were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM). The results show that the as-prepared AlOOH is stable, transparent, and crystalline, and it is rodlike with an average diameter of about 5 nm and a length of about 100 nm. The reaction temperature and time have important influences on the diameter and uniformity of the products. Besides, it was found that the anti-ultraviolet effect of silk-cotton fabrics was improved significantly after finishing by nano AlOOH solution.

scholarly journals Misfit phase (BiSe)1.10NbSe2 as the origin of superconductivity in niobium-doped bismuth selenide

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Machteld E. Kamminga ◽  
Maria Batuk ◽  
Joke Hadermann ◽  
Simon J. Clarke
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Impurity Phase ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Niobium Doped ◽  
Microscopy Techniques ◽  
Superconducting Behaviour

Abstract Topological superconductivity is of great contemporary interest and has been proposed in doped Bi2Se3, in which electron-donating atoms such as Cu, Sr or Nb have been intercalated into the Bi2Se3 structure. For NbxBi2Se3, with Tc ~ 3 K, it is assumed in the literature that Nb is inserted in the van der Waals gap. However, in this work an alternative origin for the superconductivity in Nb-doped Bi2Se3 is established. In contrast to previous reports, it is deduced that Nb intercalation in Bi2Se3 does not take place. Instead, the superconducting behaviour in samples of nominal composition NbxBi2Se3 results from the (BiSe)1.10NbSe2 misfit phase that is present in the sample as an impurity phase for small x (0.01 ≤ x ≤ 0.10) and as a main phase for large x (x = 0.50). The structure of this misfit phase is studied in detail using a combination of X-ray diffraction and transmission electron microscopy techniques.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

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.

scholarly journals Quartz Crystallite Size and Moganite Content as Indicators of the Mineralogical Maturity of the Carboniferous Chert: The Case of Cherts from Eastern Asturias (Spain)

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Celia Marcos ◽  
María de Uribe-Zorita ◽  
Pedro Álvarez-Lloret ◽  
Alaa Adawy ◽  
Patricia Fernández ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallite Size ◽  
Archaeological Sites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Infrared And Raman Spectroscopy ◽  
First Time ◽  
Geological Formations

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.

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