Deposition and stripping processes of tin on gold film electrodes studied by surface conductance

Abstract

The CV and surface conductance (SC) responses of tin species adsorbed on evaporated gold film electrodes were studied as a function of the potential window and the potential sweep rate. Sn adatoms were generated either, by reducing Sn(II) present in the solution (u p d) or by first irreversibly adsorbing Sn(II) and then reducing it in the supporting electrolyte alone. The experimental results show that at potentials about E ≈ −0.25 V(versus SCE), all the Sn(II) is reduced to Sn(0) and this species is adsorbed on the electrode surface. The subsequent oxidation of Sn(0) leads to Sn(II) ad , adsorbed on the electrode. This species desorbs only when the Sn(II) ad is further oxidised to soluble Sn(IV). The number of electrons involved in the reduction of Sn(II) to Sn(0) and vice versa is two. On the other hand, the analysis of the resistance measurements at low coverage is made by applying the surface Linde's rule. This leads to the conclusion that the Sn(0) behaves as an interstitial impurity. SC experiments, made in the potential region corresponding to Sn bulk deposition, suggest the formation of a bulk Sn-Au alloy.

Voltammetric Study of Tin Electrodeposition on Polycrystalline Gold from Sulfuric and Methanesulfonic Acid

“…In SA, peak A2 develops a shoulder (A2') around 0.09 V vs. NHE, which is absent in MSA. Previous reports 12,15,16 have suggested that peak A2 corresponds to stripping of Au-Sn alloys, while peak A3 corresponds to stripping of bulk deposited tin. Tin -gold alloy formation can be associated to underpotential deposition in the sense that the interaction between both Sn adatoms and dissolved Sn with the gold substrate exceeds the binding energy between the Sn atoms.…”

High Areal Capacity Porous Sn-Au Alloys with Long Cycle Life for Li-ion Microbatteries

“…The spontaneous formation of SnAu alloy can be explained by the fact that under sufficient reductive potentials interaction between both surface adsorbed Sn and dissolved Sn with the gold substrate exceeds the binding energy between the Sn atoms. As a result, Sn deposition on gold leads to place exchange and hence results in surface alloying 35,36 . Similar electrodeposition process carried out on Au thin films prepared by physical vapor deposition (PVD) resulted in pure Sn phases rather than SnAu alloys ( Supplementary Fig.…”

Elimination of oxidation and decomposition by SnCl2 in the SERS study of pyridoxine on a roughened Au electrode

“…It is worth noting that the presence of Sn(IV) does not have any SERS signals (not shown) because Sn(IV) is fully coordinated [33] with Cl − as SnCl 6 2− in HCl solution, which neither undergoes hydrolysis nor adsorbs on the surface. It has been confirmed that Sn(II) would be oxidized to Sn(IV) and thus desorbed above −0.3 V. [21,22] While shifting the potential negatively from the OCP (−0.39 V) as did in Fig. 3, high-quality SERS spectra of PN start emerging around −0.5 V (accompanying disappearance of bands at 670 and 570 cm −1 from the hydrolysis of Sn(II)), reach the maximum in intensity at ∼−0.65 V, and disappear after −0.8 V. The assignments of PN bands in the present paper are performed by referring to the literatures of 4-(hydroxymethyl)pyridine by Birke et al [35] and VB 6 by Cinta et al [15] Though the normal Raman (NR) spectra of VB 6 solid and aqueous solution at different pH values in Cinta's study offer important information, the reliability of the SERS spectra they obtained on Ag sol is limited for plausible decomposition (similar cases were also observed in their SERS studies on vitamin PP [36,37] ).…”