Redox Reactions of Iron and Uranium Dioxide in Simulated Cement Pore Water Under Anoxic Conditions

2002 ◽  
Vol 757 ◽  
Author(s):  
Daqing Cui ◽  
Kastriot Spahiu ◽  
Paul Wersin
Keyword(s):  
Photoelectron Spectroscopy ◽  
Redox Reactions ◽  
Pore Fluid ◽  
Laser Raman Spectroscopy ◽  
X Ray Diffraction ◽  
Exchange Reactions ◽  
Anoxic Conditions ◽  
X Ray ◽  
Laser Raman ◽  
Corrosion Of Iron

Results on the chemical behavior of Fe(0) and UO2(s), as well as the interaction between fresh and corroded iron with U(VI) in simulated cement contacting alkaline solution are reported. Batch experiments were conducted under anoxic conditions at different alkalinities and salt concentrations to investigate: (a) the corrosion of iron foils (b) the U(VI) removal by fresh, aged and pre-treated (with FeS or Fe3O4 layers) iron surfaces in a simulated cement pore fluid, (c) the dissolution rates of newly reduced UO2.00 slices in simulated cement pore fluid and KOH solutions (pH 12.7) and (d) the isotope exchange reactions between dissolved 235U(VI) and 238UO2(s). The reacted iron and UO2(s) surfaces were analyzed by X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectra (SEM-EDS), laser Raman spectroscopy and X-ray photoelectron, spectroscopy (XPS).

scholarly journals Effect of Graphene Oxide Concentration in Electrolyte on Corrosion Behavior of Electrodeposited Zn–Electrochemical Reduction Graphene Composite Coatings

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 758 ◽  
Author(s):  
Yang ◽  
Zhang ◽  
Wang ◽  
Wang ◽  
Chen ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Laser Raman Spectroscopy ◽  
304 Stainless Steel ◽  
Sulfate Electrolyte ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tafel Polarization ◽  
Laser Raman

Pure Zn and Zn–ERGO composite coatings were prepared by direct current electrodeposition on 304 stainless steel. Samples were characterized by X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS), and laser Raman spectroscopy (Raman). Results obtained have shown that the concentration of GO sheets in zinc sulfate electrolyte has an important effect on the preferred crystal orientation and the surface morphology of Zn–ERGO composite coatings. A study of the corrosion behavior of the coatings by Tafel polarization and electrochemical impedance spectroscopic (EIS) methods leads to the conclusion that the Zn-1.0 g/L ERGO composite coating possesses the best corrosion resistance compared to the pure Zn coating and other composite coatings in this study.

Synthesis and characterization of a new trimetallic compound (NH4)Ni2.4Co0.6O(OH)(MoO4)2•1.5H2O

2014 ◽  
Vol 29 (4) ◽  
pp. 379-382 ◽  
Author(s):  
Sandra Amaya ◽  
Johana Arboleda ◽  
Adriana Echavarría
Keyword(s):  
Thermal Analysis ◽  
Laser Raman Spectroscopy ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Laser Raman ◽  
Fourier Transformed Infrared Spectroscopy

A new trimetallic compound with formula (NH4)Ni2.4Co0.6O(OH)(MoO4)2•1.5H2O was obtained by hydrothermal synthesis. The solid was characterized by X-ray diffraction, thermal analysis (thermogravimetric analysis and differential thermal analysis), Fourier-transformed infrared spectroscopy, Laser Raman spectroscopy, and chemical analysis by atomic absorption, confirming the formation of the layered phase ϕy. Crystallographic studies showed that the compound obtained is trigonal with hexagonal unit-cell parameters, a = 6.0468 ± 0.0016 Å and c = 21.8433 ± 0.0001 Å, and space group R-3m.

X-ray powder diffraction data for a new compound (NH4)H2Co2O(OH)(MoO4)1.6(WO4)0.4•H2O type ϕy

2018 ◽  
Vol 33 (4) ◽  
pp. 315-318 ◽  
Author(s):  
Adriana Echavarría ◽  
Sandra L. Amaya
Keyword(s):  
Raman Spectroscopy ◽  
Lamellar Structure ◽  
Laser Raman Spectroscopy ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
X Ray ◽  
Laser Raman ◽  
Ir Laser ◽  
Ft Ir

A new trimetallic compound with formula (NH4)H2Co2O(OH)(MoO4)1.6(WO4)0.4•H2O and lamellar structure was prepared by hydrothermal synthesis. The solid was characterized using X-ray diffraction (XRD), thermogravimetric (TGA) and differential thermal (DTA) analyses, Fourier-transform infrared spectroscopy (FT–IR), laser Raman spectroscopy (LRS), and atomic absorption spectroscopy (AA). Crystallographic studies showed that the solid crystallizes with hexagonal symmetry in space group R-3 m with a = 6.0807 and c = 21.7591 Å.

Preparation of Graphene by Green Reduction Method and Characterization

2013 ◽  
Vol 807-809 ◽  
pp. 515-520 ◽  
Author(s):  
Dong Zhi Chen ◽  
Xue Mei Lin
Keyword(s):  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Graphite Oxide ◽  
Laser Raman Spectroscopy ◽  
X Ray Diffraction ◽  
Ultrasonic Dispersion ◽  
Environment Friendly ◽  
X Ray ◽  
Laser Raman ◽  
Transmission Electron

Graphite oxide was prepared by Hummers method and got graphene oxide by ultrasonic dispersion in water, and using a cheap and environment-friendly fructose as reductant, graphene oxide could be reduced into graphene under mild condition. Meanwhile, the structure and morphology of obtained product was characterized and analyzed by testing methods such as Fourier transform Infrared spectroscopy, X-ray diffraction, Laser Raman spectroscopy, Transmission electron microscope and so on. In addition, the electrical conductivity of obtained graphene was determinated.The experimental results show that graphite oxide can be reduced by fructose under mild conditions and can get graphene with good structure and dispersibility. And the electrical conductivity of graphene prepared by the reduction of graphite oxide with fructose is 35.7 Scm-1, which has great improvement on conducting performance compared with graphite oxide. Moreover, It is non-toxic, non-polluting and friendly to the environment in preparation process of graphene, which lays the groundwork for mass production of graphene materials.

Composition Oxidation and Chemical Etching Properties of a New Amorphous Silicon-Boron Thin Film

1987 ◽  
Vol 95 ◽  
Author(s):  
B. Y. Tong ◽  
S. K. Wong ◽  
J. Yao ◽  
W. N. Lau ◽  
N. Du ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Chemical Etching ◽  
Auger Spectroscopy ◽  
Laser Raman Spectroscopy ◽  
X Ray Diffraction ◽  
Electrical And Optical Properties ◽  
X Ray ◽  
Laser Raman ◽  
Amorphous Nature ◽  
Solid Film

AbstractWhen silane, with more than 0.1% of diborane in the gas mixture, are co-pyrolyzed at temperatures below 540°C, an amorphous silicon-boron alloy is formed. The composition of the solid film was determined by SINS and Auger spectroscopy. The amorphous nature of the films was established by X-ray diffraction, laser Raman spectroscopy, and TEM electron diffraction. Electrical and optical properties of this material are reported. Oxidation and chemical etching of this material were also studied.

scholarly journals Electrodeposited MnO2-based Capacitive Composite Electrodes for Pb2+ Adsorption

2020 ◽  
Vol 71 (7) ◽  
pp. 284-298
Author(s):  
Tang Chang-Bin ◽  
Niu Hao ◽  
Lu Yu-Xuan ◽  
Wang Fei ◽  
Zhang Yu-Jie ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Removal Rate ◽  
Nickel Foam ◽  
High Specific Capacitance ◽  
Laser Raman Spectroscopy ◽  
Order Kinetic ◽  
Composite Electrodes ◽  
X Ray ◽  
Laser Raman ◽  
Low Concentrations

In order to effectively realize the removal of low concentrations of lead ions in wastewater via capacitive deionization technology, MnO2 composite electrodes were prepared by a galvanostatic co-deposition approach, where polyaniline (PANI) and graphene were added to an MnO2 deposition solution and nickel foam was chosen as the substrate of the electrode. The microstructure, capacitance characteristics and adsorption behavior of Pb2+ ions of the electrodes were analyzed by scanning electron microscopy, X-ray diffraction, X ray photoelectron spectroscopy, laser Raman spectroscopy, cyclic voltammetry and capacitance deionization processes. The experimental results showed that the MnO2-PANI-graphene composite electrode has a high specific capacitance (132.8 F/g) and a 61.8% removal rate for simulated wastewater containing 20 mg/L Pb2 + ions under the conditions of 30�C and 1 mA/cm2, with the addition of 1 g/L PANI and 3 g/L graphene, respectively. Electroadsorption process was in accordance with the Lagergren quasi-second-order kinetic equation. The co-deposition of PANI and graphene oxide could play obvious role in enhancing the adsorption capacity and stability of the electrodes.

Anomalous solid state reaction between SiC and Pt

1990 ◽  
Vol 5 (3) ◽  
pp. 601-608 ◽  
Author(s):  
T.C. Chou
Keyword(s):  
Solid State ◽  
Diffusion Zone ◽  
Solid State Reaction ◽  
Periodic Structures ◽  
Amorphous State ◽  
Laser Raman Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Raman ◽  
Auger Microscopy

Periodic structures are generated by solid state reaction between platinum (Pt) and silicon carbide (SiC). At temperatures above 900°C, periodic structures consisting of alternating layers of platinum silicides and carbon are produced in the diffusion zone. The composition profile across the diffusion zone and the chemistry of the periodic structures are investigated by scanning electron microscopy (SEM), scanning Auger microscopy (SAM), x-ray diffraction (XRD), and laser Raman microprobe. The formation of the platinum silicides causes an interfacial melting between Pt and SiC. X-ray diffraction indicates that Pt3Si is formed at 900°C, while Pt2Si is formed at 1000 °C. Laser Raman spectroscopy indicates that carbon is in either an amorphous state or a highly ordered graphitic state, depending upon its location from the reaction interface. The mechanism of formation of the periodic structure is discussed in terms of the solubility of carbon in platinum silicide during the solidification process.

An X-ray Photoelectron (ESCA) and Laser Raman Spectroscopic Investigation of Aluminum Perrhenate

1980 ◽  
Vol 34 (6) ◽  
pp. 624-626 ◽  
Author(s):  
Lawrence Salvati ◽  
Gerald L. Jones ◽  
David M. Hercules
Keyword(s):  
Raman Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Heterogeneous Catalysts ◽  
Laser Raman Spectroscopy ◽  
Compound Formation ◽  
Reduction Behavior ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Laser Raman ◽  
Significant Interest

Compound formation in supported heterogeneous catalysts is an area of significant interest. In the present study, Al(ReO4)3 was prepared and characterized by x-ray photoelectron spectroscopy and laser Raman spectroscopy. Characteristic spectra for Al(ReO4)3 are shown and compared to several rhenium reference compounds. The reduction behavior of Al(ReO4)3 is also explored; it was completely reduced to elemental rhenium in H2 at 500°C.

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