scholarly journals Electrodeposition process of perrhenate ions from KNO3 and Na2SO4 background electrolytes in the presence of citric acid

2020 ◽  
pp. 4-12
Author(s):  
Nazerke Zhumasheva ◽  
Leyla Kudreeva ◽  
Akmerey Kalyyeva ◽  
Gulzhan Badavamova
Keyword(s):  
Citric Acid ◽  
Sodium Sulfate ◽  
Background Electrolyte ◽  
Nickel Sulfate ◽  
Potassium Nitrate ◽  
X Ray ◽  
Oxidation Potentials ◽  
Reduction And Oxidation ◽  
Deposited Film ◽  
Background Electrolytes

Processes involved in the electrodeposition of perrhenate ions were studied from two different potassium nitrate and sodium sulfate background electrolytes in the presence of citric acid on graphite electrode by cyclic voltammetry method. Anodic and cathodic potentials of deposited film were determined. After electrolysis process, morphology and content of obtained deposited layers were investigated by SEM and X-Ray methods. The coated film from sodium sulfate background electrolyte was not uniform and Re content was 60.83-65.5%, in case of potassium nitrate electrolyte, the deposited film was more densely located, and Re content was 80.94-82.52%. In the presence of nickel sulfate and citric acid, an alloy was formed with content of Re 80.94-82.52%, 14.10-11.83% of Ni, 4.96-5.66% of impurities, which were confirmed by X-Ray method. The current density decreased with addition of citric acid into sodium sulfate background electrolyte and in cathodic area, the reduction potential of perrhenate ions remained the same, but oxidation potentials changed from 0.25 to 0.35 V and from 0.5 to 0.6 V. The influence of citric acid on potentials of the processes of reduction and oxidation of perrhenate ions from potassium nitrate gave following results: reduction peaks shifted from -0.35 to -0.55 V, and multi peaks of oxidation appeared which were not noticeable without citric acid. It was shown that citric acid has inhibitory effect on reduction and oxidation of perrhenate ions. It is shown that the electrochemical reduction of perrhenate ions leads to the formation of rhenium dioxide in different forms.

scholarly journals Surface Stoichiometry and Depth Profile of Tix-CuyNz Thin Films Deposited by Magnetron Sputtering

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3191
Author(s):  
Arun Kumar Mukhopadhyay ◽  
Avishek Roy ◽  
Gourab Bhattacharjee ◽  
Sadhan Chandra Das ◽  
Abhijit Majumdar ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Film Surface ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Relative Composition ◽  
Transmission Electron ◽  
Deposited Film ◽  
Deposited Films

We report the surface stoichiometry of Tix-CuyNz thin film as a function of film depth. Films are deposited by high power impulse (HiPIMS) and DC magnetron sputtering (DCMS). The composition of Ti, Cu, and N in the deposited film is investigated by X-ray photoelectron spectroscopy (XPS). At a larger depth, the relative composition of Cu and Ti in the film is increased compared to the surface. The amount of adventitious carbon which is present on the film surface strongly decreases with film depth. Deposited films also contain a significant amount of oxygen whose origin is not fully clear. Grazing incidence X-ray diffraction (GIXD) shows a Cu3N phase on the surface, while transmission electron microscopy (TEM) indicates a polycrystalline structure and the presence of a Ti3CuN phase.

Study of Low-Grade Nickel Laterite Processing Using Palm Shell Charcoal as Reductant

2020 ◽  
Vol 1000 ◽  
pp. 436-446
Author(s):  
Bambang Suharno ◽  
Nolzha Primadha Ilman ◽  
Achmad Shofi ◽  
Deni Ferdian ◽  
Fajar Nurjaman
Keyword(s):  
Sodium Sulfate ◽  
Selective Reduction ◽  
Reduction Process ◽  
Low Grade ◽  
X Ray Diffraction ◽  
X Ray ◽  
Palm Shell ◽  
Higher Temperature ◽  
Nickel Grade

This study was conducted to investigate the effect of palm shell charcoal reductant in the selective reduction of nickel ore with the addition of additive at various temperatures and times. In this present work, 10 wt. % of sodium sulfate as additive and 5, 10, 15 wt. % of palm shell charcoal as reductants were used. The reduction of nickel ore was performed at 950oC, 1050oC, and 1150oC for 60, 90, and 120 minutes. A wet magnetic separation method was then carried out to separate the concentrates and tailings. Characterization of reduced ore was performed by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), while the composition of ferronickel in concentrate was identified by X-Ray Fluorescence (XRF). The result showed that the higher temperature reduction, the higher of nickel grade, and its recovery at the concentrate. Nevertheless, the longer reduction time and the more reductant in nickel ore lowering the nickel grade and its recovery in the concentrate. The optimum condition in this selective reduction process was obtained with the addition of 5 wt. % of reductant and 10 wt. % of sodium sulfate in nickel ore, which was reduced at 1150oC for 60 minutes. It resulted in 4.60% and 73.23% for nickel grade and its recovery, respectively.

X-ray crystal analysis of the substrates of aconitase. II. Anhydrous citric acid

1960 ◽  
Vol 13 (5) ◽  
pp. 418-426 ◽  
Author(s):  
C. E. Nordman ◽  
A. S. Weldon ◽  
A. L. Patterson
Keyword(s):  
Citric Acid ◽  
X Ray

scholarly journals In operando XAS investigation of reduction and oxidation processes in cobalt and iron mixed spinels during the chemical loop reforming of ethanol

2017 ◽  
Vol 5 (39) ◽  
pp. 20808-20817 ◽  
Author(s):  
F. Carraro ◽  
O. Vozniuk ◽  
L. Calvillo ◽  
L. Nodari ◽  
C. La Fontaine ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Oxygen Carriers ◽  
X Ray ◽  
Oxidation Processes ◽  
Reduction And Oxidation ◽  
In Operando ◽  
Operando Xas ◽  
X Ray Absorption

FeCo2O4 and CoFe2O4 nanoparticles have been studied as oxygen carriers for the chemical loop reforming of ethanol by using in operando X-ray absorption spectroscopy.

scholarly journals Analysis of the Deposited Film on the Nickel Anode in Molten Salt of CsF-NH4F-HF by Using Both Electrochemical Method and X-Ray Photoelectron Spectroscopy

1993 ◽  
Vol 61 (7) ◽  
pp. 742-744 ◽  
Author(s):  
Akimasa TASAKA ◽  
Keiji MIKI ◽  
Shin-ichi YAMAGUCHI ◽  
Kazunobu SATO
Keyword(s):  
Molten Salt ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Method ◽  
X Ray ◽  
Deposited Film

scholarly journals Two-Step Separation of Chitin from Shrimp Shells Using Citric Acid and Deep Eutectic Solvents with the Assistance of Microwave

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 409 ◽  
Author(s):  
Dandan Zhao ◽  
Wen-Can Huang ◽  
Na Guo ◽  
Shuye Zhang ◽  
Changhu Xue ◽  
...  
Keyword(s):  
Citric Acid ◽  
Deep Eutectic Solvents ◽  
Second Step ◽  
X Ray Diffraction ◽  
X Ray ◽  
Shrimp Shells ◽  
Ft Ir ◽  
Scanning Electron ◽  
Ft Ir Spectroscopy

In this research, a two-step extraction approach was developed for chitin preparation from shrimp shells by utilizing citric acids and deep eutectic solvents (DESs), which effectively removed minerals and proteins. In the first step, minerals of shrimp shells were removed by citric acid, and the demineralization efficiency reached more than 98%. In the second step, the removal of protein was carried out using deep eutectic solvents with the assistance of microwave, and the deproteinization efficiency was more than 88%. The results of scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction analysis (XRD), and thermogravimetric analysis (TGA) showed that the quality of DES-prepared chitin was comparable to that of traditional acid/alkali-prepared chitin. These results were realized without utilizing hazardous chemicals, which are detrimental to the environment. This research indicates that a DES-based preparation approach has the potential for application in the recovery of biopolymers from natural resources.

New Preparation for Amorphous/Nanocrystalline Ni-Mo Alloys by Electrodeposition

2013 ◽  
Vol 702 ◽  
pp. 191-196 ◽  
Author(s):  
Ning Li ◽  
Lin Lin Wang ◽  
Xiao Ming Wang ◽  
Wei Zeng Chen
Keyword(s):  
Nickel Sulfate ◽  
Nanocrystalline Structure ◽  
Sulfate Solution ◽  
Carbonate Solution ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
X Ray ◽  
Nickel Carbonate ◽  
The Stability ◽  
Better Than

The amorphous/nanocrystalline Ni-Mo alloys are obtained in alkaline nickel carbonate solution in this paper. By using X-ray diffraction (XRD) and scanning electronic microscopy (SEM) to testify microstructure and morphology of the deposits. It is found that the deposits are composed of amorphous and nanocrystalline structure phases. Compared with the nickel sulfate solution, the amorphous/nanocrystalline alloys are more accessible to be obtained in carbonate solution under the same conditions as the sulfate solution. The internal stress between the deposit and the basement is inexistent with the tiny granules and well-proportioned grains at the coating surface. The stability of the alkaline nickel carbonate solution is much better than the sulfate solution, and the deposit performance is relatively better and easy to be controlled.

Characteristics of Selective Lpcvd W Films By Silicon Reduction

1986 ◽  
Vol 71 ◽  
Author(s):  
R. V. Joshi ◽  
D. A. Smith
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Annealing Temperature ◽  
Film Surface ◽  
Silicide Formation ◽  
X Ray ◽  
Tungsten Hexafluoride ◽  
Deposited Film ◽  
Deposited Films ◽  
Oxygen Impurities

AbstractThe characteristics of Selective LPCVD tungsten films produced by silicon reduction of tungsten hexafluoride are presented. The tungsten films deposited using Si(100), Si(111) and polysilicon undoped and doped substrates are analyzed by X-RAY, TEM, RBS, AES, SIMS and SEM. The as deposited bcc tungsten films are polycrystalline with a grain size 80 - 100Å. The effect of annealing temperature and time on the crystal structure of films was studied. Tungsten reacts to form tungsten silicide at 600°C. The silicide grain size is of the order of 100 - 200Å at 600°C and increases gradually to 400 - 500Å at 1000°C. The oxygen impurities in the film retard the silicide formation further at 1000°C. Silicon from the substrate out-diffuses to the film surface and reacts with the presence of oxygen impurities in the annealing ambient to form Si-O at 1000°C. As deposited film resistivities of 130-140 micro-ohm-cm are achieved reproducibly and reach 60-70 micro-ohm-cm after 1000°C annealing in nitrogen or argon ambient. The impurities H, C, O and F are found in the as deposited films.

X-Ray Microtomography of an Astm C109 Mortar Exposed to Sulfate Attack

1994 ◽  
Vol 370 ◽  
Author(s):  
D.P. Bentz ◽  
Nicos. S. Martys ◽  
P. Stutzman ◽  
M. S. Levenson ◽  
E.J. Garboczi ◽  
...  
Keyword(s):  
Cement Paste ◽  
Sodium Sulfate ◽  
Three Dimensional ◽  
Sulfate Solution ◽  
Sulfate Attack ◽  
Sodium Sulfate Solution ◽  
Mortar Sample ◽  
Air Voids ◽  
X Ray ◽  
Dimensional Image

AbstractX-ray microtomography can be used to generate three-dimensional 5123 images of random materials at a resolution of a few micrometers per voxel. This technique has been used to obtain an image of an ASTM C109 mortar sample that had been exposed to a sodium sulfate solution. The three-dimensional image clearly shows sand grains, cement paste, air voids, cracks, and needle-like crystals growing in the air voids. Volume fractions of sand and cement paste determined from the image agree well with the known quantities. Implications for the study of microstructure and proposed uses of X-ray microtomography on cement-based composites are discussed.

Microstructure Characterization of the Reaction Interface between CBN Grain and Titanium-Deposited Film

2012 ◽  
Vol 538-541 ◽  
pp. 166-171
Author(s):  
Wen Feng Ding ◽  
Yang Min Liang ◽  
Jian He ◽  
Li Tang ◽  
Jie Yu ◽  
...  
Keyword(s):  
Heating Temperature ◽  
Cubic Boron Nitride ◽  
High Vacuum ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Energy Dispersion Spectrometer ◽  
Heat Treated ◽  
Deposited Film

Cubic boron nitride (CBN) abrasive grains with surface titanium-deposited film were heat-treated during 550-950°C for 60 min under high vacuum circumstance. Detailed interfacial compounds analysis by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersion spectrometer (EDS), differential thermal analysis (DTA) indicates that the interfacial reactions are much dependent on the heating temperature to some extents, and the reaction products, TiN, TiB2 and TiB chiefly form the network structure. In particular, at 950°C the transition layers with excellent performance, CBN/TiB2/TiB/(TiB+TiN)/TiN/CBN, is realized.

Sign in / Sign up

Export Citation Format

Share Document