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Pereira N.M.,CIQ L4 | Fernandes P.M.V.,CIQ L4 | Pereira C.M.,CIQ L4 | Silva A.F.,CIQ L4
Journal of the Electrochemical Society | Year: 2012

The use of deep eutectic solvents (DES) for metal electrodeposition has become an area of interest in the recent years however the use of additives on the electrodeposition from deep eutectic solvents is still an unexplored area. In this study we describe the influence of the tartrate ion on the deposition mechanism of zinc and on the resultant morphology of the deposits. Electrochemical techniques were used to characterize the deposition process and scanning electron microscopy was used to study the deposit morphology. It is shown that the presence of potassium hydrogen tartrate in ethaline does not alter the generic voltammetric profile of zinc in solution but in contrast the presence of tartaric acid cause major modifications. From the analysis of the chronoamperometric transients a 3D progressive nucleation mechanism is proposed for the deposition of zinc in absence and in the presence of potassium hydrogen tartrate. In the presence of tartaric acid a 2D progressive nucleation mechanism is proposed for the initial part of the deposition then changing to a 3D progressive mechanism. The SEM images reveal that both additives change the morphological characteristics of the deposits. However the use of tartaric acid introduces a more dramatic change. © 2012 The Electrochemical Society. All right reserved.

Salome S.,CIQ L4 | Pereira N.M.,CIQ L4 | Ferreira E.S.,CIQ L4 | Pereira C.M.,CIQ L4 | Silva A.F.,CIQ L4
Journal of Electroanalytical Chemistry | Year: 2013

In this work we present a fundamental study of the electrodeposition of tin from Deep Eutectic Solvents (DES) formed by a mixture of choline chloride and different hydrogen bond donors (HBD). Results shows that choline chloride based solvents can be successfully used for the electrodeposition of tin. Furthermore we demonstrate that the choice of hydrogen bond donor does not affect, significantly, the chemistry of tin in solution and we characterize the first stages of tin deposits at glassy-carbon (GC) electrode. The electrochemical characterization of tin deposits is carried out using cyclic voltammetry and chronoamperometry. The comparison of the theoretically and experimentally obtained current transients via dimensionless plots based on Bewick-Fleischman-Thirsk (BFT) theory, Scharifker and Hills (SH) and Scharifker and Mostany (SM) models and a non-linear fitting method showed that tin nucleation on GC surface occurs though a 3D instantaneous process with growth controlled by diffusion. © 2013 Elsevier B.V.

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