Synthesis and characterization of nickel tungsten alloys by electrodeposition

Eliaz, Noam; Sridhar, T. M.; Gileadi, E.

doi:10.1016/j.electacta.2004.11.038

Cited by 208 publications

(117 citation statements)

References 18 publications

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“…The electrodeposition process.-In recent years we have been studying the mechanism of induced co-deposition from aqueous solutions of alloys of Tungsten [17][18][19][20][21][22][23] and Rhenium [1][2][3][4] with the iron-group metals. The sources of the refractory metal in solution were WO 2− 4 and ReO − 4 , respectively.…”

Section: Effect Of Deposition Time and Current Density On The Surfacementioning

confidence: 99%

The Initial Stages of Electrodeposition of Re-Ni Alloys

Berkh

Eliaz

Gileadi

2014

J. Electrochem. Soc.

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The early stages of Re-Ni alloy deposition from citrate electrolytes were studied in terms of the apparent faradaic efficiency (FE) of the deposition process, the composition of the deposits and their morphology. The deposition time was varied in the range of 0.05 to 60 seconds. The apparent FE of the deposition process was calculated as the ratio between the charge consumed in electrochemical stripping of the deposit and the charge consumed during electrodeposition. The apparent FE and Re-content in the deposits (measured by energy dispersive X-ray spectroscopy) were shown to decrease with deposition time. Anomalous values of the FE, well above 100%, were observed at short deposition times. Under these conditions, the deposition of material consisting of nanoparticles with diameters of 50-80 nm was observed by scanning electron microscopy studies, supporting the anomalous high deposition rates. This behavior is indicative of chemical reactions taking place at short times in parallel with electrodeposition. The effects of deposition time on the apparent FE and Re-content in the deposits are explained by the changes in catalytic activity of the cathode surface during deposition. Electroplating and electroless plating of Re-based alloys has been investigated in our laboratory in recent years.1-7 Rhenium alone can be deposited, but the faradaic efficiency (FE) is very low and the layer formed is of poor quality and does not adhere well to the substrate. Addition of salts of one of the iron-group metals, (Me = Ni, Co or Fe) leads to high FE and high Re-content of the alloys formed. When alloy deposition is concerned, there are, by definition, at least two reactions occurring in parallel. Moreover, hydrogen evolution is commonly observed. In the particular case of electroplating of Re-Ni alloys, it is common to use citric acid as a complexing agent. This can give rise to several complexes of Ni with the citrate ions, depending on pH, as well as complexes of Re with citrate, and even a triple complex of Re-Ni-Cit. The overall reaction for deposition of Re is given by Eq. 1, in which 7 electrons are involved.Thus, a detailed evaluation of all the steps would be extremely difficult, if at all possible. In several papers in the literature it was shown that this reaction follows the stepwise reduction of the ReO − 4 ion. Deposition of Re from acidic electrolytes was shown to proceed through formation of ReO 2 as an intermediate, followed by the complete reduction to the metal. Possible disproportionation of one of the intermediates has also been suggested as a route for electrodeposition. 8-10The intriguing question is to understand the role of the divalent ion (Me) in inducing the deposition of metallic Re. In our recent papers we proposed the mechanism shown in Eqs. 2 and 3: According to this mechanism, freshly deposited Ni 0 catalytically reduces the perrhenate ion from its complex with citrate to the 5-valent oxidation state in the rhenate ion, ReO

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Section: Effect Of Deposition Time and Current Density On The Surfacementioning

confidence: 99%

The Initial Stages of Electrodeposition of Re-Ni Alloys

Berkh

Eliaz

Gileadi

2014

J. Electrochem. Soc.

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“…2. An increase in the bath concentration of Ni 2+ has also been reported to cause a dramatic increase in the Faradaic efficiency [32], the cathode deposits obtained were silvery white. At higher concentration, the deposits obtained were dull in appearance which can be attributed to the deposition of double salts.…”

Section: Resultsmentioning

confidence: 97%

“…Gelatine was added to nickel electroplating bath as organic additive to control the deposition rate, crystallization, leveling and brightness of the deposit [32]. Less knowledge therefore is available on the mechanism of nickel deposition by using organic additives and how deposition conditions affect deposit structure and properties.…”

Section: Introductionmentioning

confidence: 99%

Electrodeposition and Morphology Analysis of Nickel Nanoparticles from Sulphate Bath

Belhamel

Kheraz

Ludwig

et al. 2010

e-J. Surf. Sci. Nanotechnol.

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The electrodeposition of Nickel in the presence of organic compound was studied systematically as function of the nature of the organic additive. The effects of various parameters such as nickel sulphate concentration, bath temperature, current density have been investigated on deposit physical appearance. The tolerance limits and the effect of combined organic additive have been identified under different experimental conditions. We have used scanning electron microscopy (SEM) to characterize the surface morphology of deposits. The SEM pictures show the formation of domain growth of nickel in which nanoparticles are mostly concentrated at domain boundaries and incorporated in the coating matrix to improve the surface mechanical properties. The coatings are found to be highly adherent and uniform by adding calixarene derivative as organic additive at very low concentration. Threedimensional AFM images confirm that the presence of calixarene derivative improves the surface smoothness. The microhardness measurements were performed and the structure of deposits was examined by X-ray diffraction.

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“…Na ovaj način je ispitan veliki broj legura na bazi prelaznih metala, npr. Ti-Ni [36], PtMo [37], Ni-Mo [31,38], Ni-Co-LaNi 5 [39], Ni-RuO 2 [40] , Ni-prelazni metali (Fe, Mo, W) [32,41,42], itd; i…”

Section: Slika 15 Izlazni Rad Elektrona Duž Periodnog Sistema Elemenunclassified

“…U ove svrhe se obično koristi amonijačno-citratno elektrohemijsko kupatilo, pri čemu se, u zavisnosti od namene, željenog sastava i morfologije legura, menjaju parametri procesa (gustina struje taloženja, vreme, temperatura, režim zadavanja strujnog signala, itd) i sastav kupatila (koncentracija elektroaktivnih vrsta i eventualno prisutnih aditiva, pH vradnost, itd). Uticaj navedenih promenljivih veličina u posmatranom procesu na sastav, mehaničke i termalne osobine dobijenih legura, podrobno je ispitivan u velikom broju naučnih istraživanja [42,49,[68][69][70]. Primena ovako pripremljenih legura Ni i W kao katalitičkih materijala u alkalnoj elektrolizi vode nije do sada detaljno ispitivana te je ideja vodilja eksperimenata urađenih u ovom radu ispitivanje mogućnosti njihove primene u ove svrhe.…”

Section: Ni-w Katode Za Alkalnu Elektrolizuunclassified

New cathode materials for hydrogen evolution produced by electrochemical codeposition of Ni and Co with Mo and W - influence of microwave radiation on their physicochemical properties

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Synthesis and characterization of nickel tungsten alloys by electrodeposition

Cited by 208 publications

References 18 publications

The Initial Stages of Electrodeposition of Re-Ni Alloys

The Initial Stages of Electrodeposition of Re-Ni Alloys

Electrodeposition and Morphology Analysis of Nickel Nanoparticles from Sulphate Bath

New cathode materials for hydrogen evolution produced by electrochemical codeposition of Ni and Co with Mo and W - influence of microwave radiation on their physicochemical properties

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