Effect of Organic Additives on Electrodeposition of Tin From Acid Sulfate Solution

Abstract

Basic electrochemical experiments on the kinetics of tin deposition from an acid sulfate solution containing organic additives were performed. The measurements showed that tin deposits with activation polarization in a narrow potential range. Organic additives like gelatin and β-naphtol inhibit the charge transfer stage of the cathodic reaction due to the formation of adsorption layers. In turn, the gluconate ions increase the rate of tin deposition due to the bonding of hydrogen ions and inhibiting hydrogen coevolution. This results in serious changes in the morphology of tin deposits from isolated polyhedron crystals (no additive) via rectangular plates (β-naphtol) and thin plates (sodium gluconate) to rounded grains (gelatin).

Electrochemical study and characterization of tin coatings with and without glucose-based additive

“…However, the wastewater from baths containing lead presents real environmental problems. To remedy this problem, several authors have suggested the addition of organic compounds 11,[14][15] or surfactants 12,16-17, which can play the same role as lead. Some efforts have been made to develop appropriate additives and to discover their modes of intervention in the deposition kinetics and thus their impact on the morphological properties and structure.…”