Tin plating in acid Sn(II) gluconate solutions containing excess of sulphate. (July 2013)

• Record Type: Journal Article
• Authors: Survila, A; Mockus, Z; Kanapeckaitė, S; Stalnionis, G; Juškėnas, R
• Is Part Of: Transactions of the Institute of Metal Finishing. Volume 91:Number 4(2013:Jul.)
• Page Start: 197
• Page End: 201
• Publication Date: 2013-07
• Subjects: Tin -- Gluconate -- Electroreduction -- Voltammetry -- Impedance -- Morphology; Metals -- Finishing -- Periodicals; Metals -- Surfaces -- Periodicals; Metallurgy -- Periodicals; 671.705
• DOI: 10.1179/0020296713Z.000000000106
• Languages: English
• ISSNs: 0020-2967

Abstract

Abstract : Voltammetry, electrochemical impedance spectroscopy, SEM and XRD techniques were applied to study tin plating in acid 0·01M Sn(II) solutions containing different amounts (0·02–0·1M) of gluconate and 0·5M Na2 SO4 . Solution pH is the main factor that governs the rate of Sn(II) reduction. An increase in pH from 2 to 5 results in a 100-fold growth in electrode impedance and a four-fold reduction in limiting current density. Spongy tin deposits are obtained in the ligand insufficient solutions at low cathodic polarisations Δ E . To obtain compact fine grained tin coatings, Δ E and/or the gluconate concentration should be correspondingly increased. Sn(II) reduction proceeds under conditions of strong inhibition involving destructive ligand chemisorption and incorporation of its fragments into deposits.