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Abstract: This paper shows the study of silver–zinc electrodeposition from a thiourea solution with added (ethylenedinitrilo)tetraacetic acid (EDTA), disodium salt and N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), trisodium salt. Voltammetric results indicated that silver–zinc alloy can be obtained applying overpotential higher than 0.495V, in Tu solution containing 1.0×10−1 molL−1 Zn(NO3)2 +2.5×10−2 molL−1 AgNO3. This was due to silver(I) ion complexation with thiourea, which shifted the silver deposition potential to more negative value and due to silver–zinc alloy deposition, which occurred at potentials more positive than the potential to zinc deposition alone. EDTA or HEDTA did not significantly affect the silver and zinc deposition potentials, but decreased the current density for silver–zinc deposition. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses of the silver–zinc deposits showed that the morphology and composition changed as a function of the conditions of deposition, viz, deposition potential (E d), deposition charge density (q d) and solution composition (silver, EDTA and HEDTA concentrations). EDS analysis of the deposits showed sulphur (S) incorporated into the silver–zinc deposit, while SEM images showed that this sulphur content seemed to improve the silver–zinc morphology, as did the presence of EDTA and HEDTA in the solution, which enhanced the sulphur incorporation into the silver–zinc deposit. X-ray diffraction (XRD) analysis of the silver–zinc deposit showed that it was amorphous, irrespective of its composition and morphology. [Copyright &y& Elsevier]

Abstract: The electrodeposition of Pb–Sn alloys from a tartrate-alkaline plating bath can lead to a deposition of pure lead or a normal codeposition of lead–tin depending on the deposition potential. The percentage of tin in the Pb–Sn deposit obtained at ∼−1.15V increases from 4.08wt.% to 20.7wt.% as the charge density rises from 2.5Ccm−2 to 5.0Ccm−2 and then decreases from 12.07wt.% to 7.52wt.% as the charge density rises from 7.5Ccm−2 to 10.0Ccm−2. SEM images show that the Pb and Pb–Sn deposits obtained from a tartrate-alkaline bath did not, in general, show dendritic growth. X-ray analysis of the deposits obtained at −0.83V with 5.0Ccm−2 or 10.0Ccm−2 indicated the presence of Pb and Pb2PtO4 and the absence of Sn. However, those obtained at −1.15V and the same charge densities (q d) showed the presence of Pb, Pb2SnO4, PbSnO3 and PtSn4. The Pb2PtO4 and PtSn4 compounds were formed because the electrodeposition process occurred onto Pt substrate. [Copyright &y& Elsevier]

Abstract: An alkaline Pb–Sn plating bath containing sorbitol as additive has been developed, which has the advantage of low toxicity and ease of handling relative to fluoborate baths, etc. The Pb–Sn deposition voltammetric curve from this bath revealed two deposition processes, at −0.87 and −1.17V. The voltammetric studies at various sweep rates indicate that the Pb–Sn deposition process is controlled by mass transport. The joint diffusion coefficient of the Pb(II) and Sn(II) sorbitate complex species is 1.15×10−6 cm2 s−1. SEM analysis showed that the films produced at −0.87 and −1.17V are, respectively, composed of dendritic or hexagonal crystals, showing that co-deposition of tin hindered dendritic growth. EDS of the Pb–Sn films showed that the deposit obtained at −0.87V is pure lead, while that at −1.17V, with 5.0 or 10.0Ccm−2, has 19.10wt% Sn or 26.35wt% Sn, respectively. It was observed that the Pb–Sn electrodeposited films were grey at both deposition potentials (−0.87 and −1.17V) and deposition charges (5.0 and 10.0Ccm−2). X-ray spectra showed that at the potential −0.87V a mixture of Pb, PbPt4 and Pb2PtO4 were deposited, while at −1.17V, Pb, β-Sn, and PbSnO3 were deposited. [Copyright &y& Elsevier]

Abstract: The electrodeposition of lead on to a copper substrate from a plumbite solution, 0.1M Pb(NO3)2 +0.2M sorbitol+NaOH, was investigated over a range of concentrations of the hydroxide. Interactions between the copper electrode surface and the lead deposit were investigated by the voltammetric technique. From these experiments, it was concluded that underpotential deposition (upd) of lead does not occur on copper and that lead nucleation occurs as soon as deposition is operative from −0.78V. Energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) of the lead films corroborates this result. Lead films obtained at −0.78 and −0.90V were adherent and could be used as a support in battery plates, but this adhesion of lead to copper cannot be attributed to upd. SEM analysis showed that films produced at potentials down to −0.90V were smooth and that this is the critical potential for a transition from dense to pyramidal or dendritic crystals patterns. The dendritic crystallites can be transformed into a high-purity lead powder. [Copyright &y& Elsevier]

Electrodeposition of lead on copper was investigated experimentally, mainly the adherence of the lead plate and, if possible to obtain films with characteristics suitable for use in lead battery technology.Under potentiodynamic and chronopotentiometric conditions, the lead films deposited from alkaline glycerol solutions on copper were sufficiently adherent for this substrate showed to be potentially useful as a cathode for lead deposition. Scanning electron microscopy (SEM) photographs showed that there was no dendritic growth of lead film on copper substrate, which is thus acceptable as a support in battery plates. With the help of energy dispersive X-ray spectroscopy (EDS), an explanation has been offered for the adherence of the lead deposits to the copper substrate. It was concluded that lead film deposited prior to lead bulk deposition favors the adhesion of the electrodeposits. [Copyright &y& Elsevier]

Abstract: The electrodeposition of copper–zinc on 1010 steel from a non-cyanide alkaline electrolyte based on EDTA (ethylenediaminetetraacetic acid, disodium salt) — alkaline with various proportions of copper and zinc ions, was investigated. The complexation of copper and zinc by EDTA stabilized the solution. The deposition potential and the composition of the Cu–Zn bath were shown to influence the composition, morphology and phase composition of the Cu–Zn deposits. Scanning electron microscopy analysis showed that the best conditions to obtain smooth Cu–Zn deposits were at −1.45V, with Cu70–Zn30 and Cu50–Zn50 baths, and at −1.60V, with Cu30–Zn70. Besides being smoother than others, these deposits were golden in colour. Energy-dispersive X-ray spectroscopy analysis showed that a Zn content above 60wt.% in the Cu–Zn deposits was achieved from the last bath, at −1.45V. X-ray diffractograms of the Cu-Zn deposits produced at -1.45V, from Cu70-Zn30, Cu50-Zn50 and Cu30-Zn70 baths, indicated the occurrence of phases Cu0.61Zn0.39 and Cu, CuZn, Cu5Zn8 and Cu, CuZn, Cu5Zn8, CuO, Cu0.61Zn0.39, respectively. For the Cu30–Zn70 bath at −1.60V, Cu, CuZn, Cu5Zn8, and CuO phases were observed. [Copyright &y& Elsevier]

Abstract: The electrodeposition of silver onto platinum from an alkaline electrolyte containing EDTA (ethylenediaminetetraacetic acid) was investigated. Voltammetric studies indicated that the reduction process is influenced thermodynamically and kinetically by the EDTA concentration. Moreover, hydrodynamic studies showed that silver deposition involved different silver complexes, depending on the EDTA concentration. Scanning electron microscopy analysis showed that the presence of EDTA in the plating bath was beneficial, since the silver films coated the substrate completely, regardless of the EDTA concentration. Furthermore, the silver films were uniform, without cracks and with fine granularity, while in the absence of EDTA the granularity was rough. Energy dispersive X-ray spectroscopy showed that carbon was not incorporated into the silver films. X-ray diffraction analysis of the Ag deposits obtained at various EDTA concentrations indicated the occurrence of polycrystalline silver and that the main orientation was (111), as found in the silver film obtained from a cyanide bath. [Copyright &y& Elsevier]