Electrolytic Reduction of Aqueous Tungstate Solutions

Holt, M. L.; Vaaler, L. E.

doi:10.1149/1.2773824

Cited by 40 publications

(25 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…There is no final agreement as to the mechanism by which the deposition of reluctant metals occurs, and the catalytic hypothesis is merely a restatement of the phenomenon with the unknown factors termed catalytic (32,33). Furthermore, the existence of an adsorbed layer, which was deduced here, is in accordance with considerations described elsewhere (29,31,(35)(36)(37). the explanation given here supports the concepts of catalytic action of freshly deposited iron group metals.…”

Section: Discussionsupporting

confidence: 89%

Structure of Noncrystalline Co-25 a/o W Electrodeposit

Omi¹,

Yamamoto²,

Glass

1972

J. Electrochem. Soc.

View full text Add to dashboard Cite

Noncrystalline electrodeposits of Co-25 atomic per cent (a/o) W prepared from ammoniacal alkaline tartrate electrolyte were studied by x-ray diffraction. A model for the structure of this alloy was developed. The principal assumptions involved in constructing the model are based mainly on requirements for the electrodeposition. The model requires that the alloy consist of distinct basic structural units in the form of tetrahedra, each composed of three cobalt atoms and one tungsten atom. The dimensions of this structural unit correspond to those of the intermetallic compound Co3W. Certain criteria .govern the bonding of the tetrahedra to form larger aggregates. The scattermg function calculated from the model agrees quite well with the diffraction data. The model also accounts for differences in the composition of amorphous deposits prepared at different current densities. The electrochemical requirements for the formation of this structure by electrodeposition are discussed. The operation of similar processes in the electro-or chemical deposition of other alloys having stoichiometric composition is considered. * Electrochemical Society Active Member. ABSTRACTThe variables affecting the uniformity of sheet resistance for a two-step shallow phosphorus emitter diffusion were examined. The source used was POCla. The uniformity of sheet resistance (and hence surface concentration) was predominantly dependent on the variables during the deposition process.

show abstract

Section: Discussionsupporting

confidence: 89%

Structure of Noncrystalline Co-25 a/o W Electrodeposit

Omi¹,

Yamamoto²,

Glass

1972

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…The electrodeposition process depends upon several factors including concentration of precursors, conditions of electrolysis, and the physical and chemical properties of the substrate. Furthermore, it has been readily established that transition metals such as Mo and W cannot be electrodeposited alone from aqueous solution [12,13]. Yet, binary metal alloys, metal oxides, and chalcogenides may be electrodeposited from a solution containing two or more metal ions (e.g., Fe 2+ , Ni 2+ , Co 2+ , SeO 2À 3 ) [14][15][16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Cathodic electrodeposition of mixed molybdenum–selenium oxides

Hahn

Stevenson

2010

Journal of Electroanalytical Chemistry

View full text Add to dashboard Cite

“…[19] For FeÀ W codeposition, catalytic mechanisms induced by adsorbed species such as hydrogen (H ad ) or the adsorbed TM (TM ad ) are proposed. A "catalytic reduction" theory was proposed by Holt and Vaaler [21] to explain the reduction of aqueous tungstate solutions in the presence of zero-valence TM elements (i. e., Ni, Co and Fe). Three possible co-deposition mechanisms have been proposed.…”

Section: Introductionmentioning

confidence: 99%

Electrodeposition of a Rare‐Earth Iron Alloy from an Ionic‐Liquid Electrolyte

Šturm

Zavašnik

et al. 2019

ChemElectroChem

View full text Add to dashboard Cite

Rare earth element (REE)-based metals and alloys are generally synthesized by molten-salt electrolysis which is an energyintensive approach. Previous attempts to deposit alloys of rare earths from solutions at mild temperatures have met with little success. Excitingly, in this investigation we were able to electrodeposit NdÀ Fe from the 1-ethyl-3-methylimidizolium dicyanamide ([EMIM][DCA]) ionic liquid (IL) at 110°C. We observed that Nd III cannot be reduced independently, although it can be co-deposited inductively on a Cu substrate with the addition of Fe II . The transmission electron microscopy (TEM) analysis combined with electron-energy-loss spectroscopy (EELS) verified that Nd III is reduced to Nd 0 during the electrodeposition process. The TEM/EELS was also able to confirm that the deposition of the NdÀ Fe starts with the sole deposition of Fe, followed by the co-deposition of NdÀ Fe. This is in agreement with transition-state theory, which has the iron initially reduced to an activated state (Fe*), where it is able to catalyse the reduction of the rare earth from Nd III to Nd 0 . This new insight into the electrodeposition process brings us a very important step closer to being able to recycle rare earths efficiently and even to realise electrodeposited rare-earth-based permanent-magnet thin films at a mild temperature, thus giving us a sustainable, green-chemistry approach that provides a genuine alternative to high-temperature molten-salt electrolysis.[a] X.

show abstract

Electrolytic Reduction of Aqueous Tungstate Solutions

Cited by 40 publications

References 8 publications

Structure of Noncrystalline Co-25 a/o W Electrodeposit

Structure of Noncrystalline Co-25 a/o W Electrodeposit

Cathodic electrodeposition of mixed molybdenum–selenium oxides

Electrodeposition of a Rare‐Earth Iron Alloy from an Ionic‐Liquid Electrolyte

Contact Info

Product

Resources

About