Electrodeposición De Estaño Sobre Cobre Desde Solventes Eutécticos Profundos

L.A. AZPEITIA; A.E. BOLZÁN; C.A. GERVASI

Montevideo

Congreso; XXIV Congreso de la Sociedad Iberoamericana de Electroquímica, SIBAE 2020; 2020

Sociedad Iberoamericana de electroquímica

The electrodeposition process of tin from deep eutectic solvents on copper electrodes was studiedfor the case of ethaline and reline in the 293 to 353 K range by employing electrochemical techni-ques and scanning electron microscopy imaging. The voltammetric proles show the presence ofboth, underpotential and overpotential electrodeposition of tin. While the rst process (upd) in-volves surface controlled reactions, the latter (opd) is under mass transport control. SEM imagingshows the formation of nanoparticles under upd conditions and larger ones in the opd potentialregion. Analysis of chronoamperometric response indicates an instantaneous nucleation and 2Dgrowth coupled to an adsorption process during the early stages of underpotential deposition.Conversely, data obtained in the overpotential deposition range is consistent with the occurrenceof a progressive nucleation and 3D growth under diusion control. Electrochemical impedanceexperiments are characterised by Nyquist plots that exhibit two capacitive time constants and asingle capacitive time constant followed by a Warburg contribution in the upd and opd potentialranges, respectively. From rotating disc electrode data the diusion coecient of Sn(II) ions at thedierent temperatures were determined along with the corresponding diusion activation energyfor both eutectics and compared with previous data obtained for acid aqueous solutions. A reactionscheme for the electrochemical behaviour of tin on copper electrodes is proposed. Mass transportof soluble species, formation of weakly and strongly adsorbed species on copper and the diusionof tin atoms into the copper lattice are considered.