scholarly journals Electrodeposition and Electrooxidation of Bimetallic Systems Co–Ni and Cu–Ni

2015 ◽  
Vol 17 (3) ◽  
pp. 181 ◽  
Author(s):  
N.V. Ivanova ◽  
A.A. Kubylinskaya ◽  
Yu.A. Zakharov

By means voltammetry method the characteristics of the electrodeposition and anodic oxidation processes of Cu, Ni, Co and Cu–Ni, Co–Ni were investigated in ammoniacal buffer supporting electrolyte using graphite electrode. The quantity, maximum currents and potentials of anodic peaks on the voltammetric curves in the case of binary system are defined by the ratio of metal ions concentration and electrodeposition procedure. The changes in the peaks parameters were attributed to the formation of bimetallic solid solutions with various contents of the components. It was shown that the result of coelectrodeposition of two metals on an inert substrate is determined not only the nature of the components of binary systems Co–Ni and Cu–Ni, but also features of the phase composition of bimetal in nano-state.

1990 ◽  
Vol 55 (7) ◽  
pp. 1741-1749
Author(s):  
Milan Drátovský ◽  
Bohumír Grüner ◽  
Ivan Horsák ◽  
Jiří Makovička

The phase diagram of the KCN-KI binary system was measured and the published phase diagrams of the KCN-NaCN, NaI-KI and NaCN-NaI systems were verified and completed. The systems form solid solutions with minima on the liquidus and solidus curves. The solid solutions in the KCN-KI system probably have a high segregation temperature, close to the solidus curve. For the four binary systems the experimental points were fitted with liquidus and solidus curves either by applying smoothing spline functions or by using two different models. The results obtained are discussed.


Author(s):  
Shahlaa E. Ebrahime ◽  
Saja H. Alsaade

The possibility of using cork stopper particles as a biosorbent for the removal of Cd (II) and Zn (II) from simulated wastewater was studied. Batch sorption experiments of single and binary components systems were conducted as a function of pH, sorbent dosage; contact time, and agitation speed were investigated to optimize the best conditions for maximum of metal ions removal. The experimental data fitted slightly best to the Langmuir isotherm model than to Freundlich and Temkin isotherm models. The experimental data proved that the adsorption kinetic of Cd (II) and Zn (II) could be described by a pseudo-first order model. The sequence for metal ions removal in single and binary system was Zn (II)> Cd (II), the removal efficiency of both metals decreased in the binary system.


2018 ◽  
Vol 619 ◽  
pp. A138
Author(s):  
V. Perdelwitz ◽  
S. Czesla ◽  
J. Robrade ◽  
T. Pribulla ◽  
J. H. M. M. Schmitt

Context.Close binary systems provide an excellent tool for determining stellar parameters such as radii and masses with a high degree of precision. Due to the high rotational velocities, most of these systems exhibit strong signs of magnetic activity, postulated to be the underlying reason for radius inflation in many of the components. Aims.We extend the sample of low-mass binary systems with well-known X-ray properties. Methods.We analyze data from a singular XMM-Newton pointing of the close, low-mass eclipsing binary system BX Tri. The UV light curve was modeled with the eclipsing binary modeling tool PHOEBE and data acquired with the EPIC cameras was analyzed to search for hints of orbital modulation. Results.We find clear evidence of orbital modulation in the UV light curve and show that PHOEBE is fully capable of modeling data within this wavelength range. Comparison to a theoretical flux prediction based on PHOENIX models shows that the majority of UV emission is of photospheric origin. While the X-ray light curve does exhibit strong variations, the signal-to-noise ratio of the observation is insufficient for a clear detection of signs of orbital modulation. There is evidence of a Neupert-like correlation between UV and X-ray data.


Author(s):  
Zahia Benredjem ◽  
Karima Barbari ◽  
Imene Chaabna ◽  
Samia Saaidia ◽  
Abdelhak Djemel ◽  
...  

Abstract The Advanced Oxidation Processes (AOPs) are promising environmentally friendly technologies for the treatment of wastewater containing organic pollutants in general and particularly dyes. The aim of this work is to determine which of the AOP processes based on the Fenton reaction is more effective in degrading the methyl orange (MO) dye. The comparative study of the Fenton, photo-Fenton (PF) and electro-Fenton (EF) processes has shown that electro-Fenton is the most efficient method for oxidizing Methyl Orange. The evolution of organic matter degradation was followed by absorbance (discoloration) and COD (mineralization) measurements. The kinetics of the MO degradation by the electro-Fenton process is very rapid and the OM degradation rate reached 90.87% after 5 min. The influence of some parameters such as the concentration of the catalyst (Fe (II)), the concentration of MO, the current density, the nature and the concentration of supporting electrolyte was investigated. The results showed that the degradation rate increases with the increase in the applied current density and the concentration of the supporting electrolyte. The study of the concentration effect on the rate degradation revealed optimal values for the concentrations 2.10−5 M and 75 mg L−1 of Fe (II) and MO respectively.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4066
Author(s):  
Xianyuan Fan ◽  
Hong Liu ◽  
Emmanuella Anang ◽  
Dajun Ren

The adsorption capacity of synthetic NaX zeolite for Pb2+, Cd2+, Cu2+ and Zn2+ in single and multi-component systems were investigated. The effects of electronegativity and hydration energy on the selective adsorption, as well as potential selective adsorption mechanism of the NaX zeolite for Pb2+, Cd2+, Cu2+ and Zn2+ were also discussed. The maximum adsorption capacity order of the heavy metals in the single system was Pb2+ > Cd2+ > Cu2+ > Zn2+, and this could be related to their hydration energy and electronegativity. The values of the separation factors (α) and affinity constant (KEL) in different binary systems indicated that Pb2+ was preferentially adsorbed, and Zn2+ presented the lowest affinity for NaX zeolite. The selective adsorption capacities of the metals were in the order, Pb2+ > Cd2+ ≈ Cu2+ > Zn2+. The trend for the selective adsorption of NaX zeolite in ternary and quaternary systems was consistent with that in the binary systems. Pb2+ and Cu2+ reduced the stability of the Si-O-Al bonds and the double six-membered rings in the NaX framework, due to the high electronegativity of Pb2+ and Cu2+ than that of Al3+. The selective adsorption mechanism of NaX zeolite for the high electronegative metal ions could mainly result from the negatively charged O in the Si-O-Al structure of the NaX zeolite, hence heavy metal ions with high electronegativity display a strong affinity for the electron cloud of the oxygen atoms in the Si-O-Al. This study could evaluate the application and efficiency of zeolite in separating and recovering certain metal ions from industrial wastewater.


2021 ◽  
Vol 23 (15) ◽  
pp. 9211-9217
Author(s):  
Guannan Qu ◽  
Rasheed Bilal ◽  
Minsi Xin ◽  
Zhong Lv ◽  
Guangyong Jin ◽  
...  

Hydrogen bond generated between DMSO and benzene binary system induced changes in the Raman properties during phase transition.


2019 ◽  
Vol 45 (17) ◽  
pp. 23119-23125
Author(s):  
C. Tabasco-Novelo ◽  
J.F. May-Crespo ◽  
A. López-González ◽  
J.A. Marín-Romero ◽  
J.J. Alvarado-Gil ◽  
...  

1966 ◽  
Vol 19 (8) ◽  
pp. 1343 ◽  
Author(s):  
TM Florence

In concentrated chloride media, nickel is reduced at far more positive potentials than in dilute solutions. The positive shift in half-wave potential increases as the ionic strength is raised, and is also greater when the cation of the supporting electrolyte has a high hydration number. Evidence is presented to show that the reduction in overpotential is due to the formation of a nickel chloride complex, [Ni(H2O)5Cl]+, which has a stoicheiometric stability constant of 0.094 � 0.009 at an ionic strength of 10.0. Spectrophotometric results show that this nickel species is not formed in low ionic strength solutions. In anhydrous methanol saturated with lithium chloride, nickel is present as the tetrachloro complex, [NiCl,]2-, which has similar polarographic behaviour to the monochloro complex. Current-potential curves recorded at a rotated pyrolytic graphite electrode enabled the behaviour of nickel to be studied in the absence of specific adsorption of the chloride ion. Nickel is reduced at more positive potentials at a dropping mercury electrode than at the pyrolytic graphite electrode, and the results indicate that this difference is due to specific adsorption of chloride on the mercury electrode.


1998 ◽  
Vol 214 (1) ◽  
pp. 241-254 ◽  
Author(s):  
L. A. Reznitchenko ◽  
N. V. Dergunova ◽  
G. A. Geguzina ◽  
O. N. Razumovskaya ◽  
L. A. Shilkina ◽  
...  

1997 ◽  
Vol 12 (12) ◽  
pp. 3254-3259 ◽  
Author(s):  
J. Font ◽  
J. Muntasell ◽  
E. Cesari ◽  
J. Pons

Ball milling has been used as a solid-state mechanical alloying technique in two binary systems of plastic crystals: neopentylglycol/pentaglycerin (NPG/PG), showing a partial solubility in the ordered phase, and 2-amino-2-methyl-1,3-propanediol/tris(hydroxymethyl) (AMP/TRIS) whose immiscibility in this ordered solid phase is almost total. For the AMP/TRIS system the stable state at room temperature was reached by milling. Contrarily, for NPG/PG, DSC measurements reveal that an annealing period is required after milling. These results have been compared with those of the pentaglycerin/pentaerythritol (PG/PE) binary system, previously studied, whose miscibility is total at room temperature.


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