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

Abstract

In this work, we have studied tin electrodeposition on polycrystalline gold electrodes from two different supporting electrolytes: sulfuric acid (SA) and methanesulfonic acid (MSA), both of them commonly used in the industry. This work aims to understand the effect of the different electrolyte anions on the deposition process. We show at least three different tin deposition mechanisms on gold: irreversible adsorption, underpotential deposition, and overpotential (bulk) deposition. Underpotential deposition leads to the formation of a layer of tin in SA and MSA with a coverage around θ Sn(H 2 SO 4) = 0.45 ML (monolayer) and θ Sn(CH 3 SO 3 H) = 0.42 ML, respectively. The UPD Sn layer is however somewhat uncharacteristic as it is associated with island formation and surface alloying. Cyclic voltammograms in an extended potential range showed five distinct peaks: two cathodic peaks associated with tin underpotential and overpotential deposition, and three main anodic peaks, corresponding to the oxidation of the bulk Sn, of the AuSn intermetallic layer, and of the adsorbed Sn(II) to Sn(IV). Both voltammetric and rotating disk electrode measurements show that the kinetics of tin electrodeposition in MSA is slower than in SA, which we ascribe to Sn-MSA complex formation in solution. Slow Sn deposition in MSA promotes AuSn formation, in contrast to SA in which bulk tin deposition is more prominent. Complete Levich-type mass transport control of tin deposition in SA and MSA was only reached at low scan rate due to concurrent HER on the uncovered gold surface during the deposition process at higher scan rates. An unexpected surface-confined passivation process is observed in both electrolytes.

Detection of Organic Additives in Copper Plating Bath Using Voltammetric Methods That Involve a Screen-printed Nano-Au Electrode

“…In the absence of copper ions, there are two oxidation peaks at about 1.25 and 1.45 V vs Ag/AgCl, which correspond to gold (hydr)oxides formation, which is consistent with previous reports [22]. There are two reduction peaks in the reverse scan at 1.05 and 0.83 V vs Ag/AgCl, which correspond to the reduction of gold (hydr)oxides to Au [22]. In the presence of 0.4 M copper ions, copper ions are deposited at a potential of 0.65 to 0.45 V vs Ag/AgCl and copper stripping peaks are observed at a potential of 0.45 to 0.65 V vs Ag/AgCl.…”

“…1(a). In the absence of copper ions, there are two oxidation peaks at about 1.25 and 1.45 V vs Ag/AgCl, which correspond to gold (hydr)oxides formation, which is consistent with previous reports [22]. There are two reduction peaks in the reverse scan at 1.05 and 0.83 V vs Ag/AgCl, which correspond to the reduction of gold (hydr)oxides to Au [22].…”

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

“…Surprisingly, the formation of SnAu alloy occurred under ambient conditions during the electrodeposition process, with no XRD peaks related to Sn detected. Such phenomenon has recently been observed elsewhere 34 and is mostly related to the nature of porous gold, which is different from bulk gold or thin films of gold. 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.…”

The Effect of Naphthalene‐Based Additives on the Kinetics of Tin Electrodeposition on Boron‐Doped Diamond Electrodes

“…The cyclic voltammogram was used as a reference to choose the potential region to record the current transients, as indicated by the red lines, from À 0.220 to À 0.460 V. Figure S1 in the Supporting Information compares the CV to the blank of the BDD electrode; these curves also show that no significant hydrogen evolution (proton reduction) is taking place in the studied potential window. Although previous studies have discussed the concurrent proton reduction on tin during its electrodeposition process on different substrates, [20][21][22][23][24] copper, [22][23][24] glassy carbon [23] and steel, [21] with an interpretation of the chronoamperometric data according to the model proposed by Palomar-Pardavé et al, [20] proton reduction on Sn does not happen below À 0.5 V, [14] and we believe that we can safely neglect proton reduction in the transients presented below. Indeed, Sn is a poor HER catalyst due to the weakness of SnÀ H bond.…”

“…[9] Up to now, only few studies have investigated the effect of additives on the early stages of the nucleation and growth of the tin deposition process. [13] In our previous work on tin electrodeposition, [14] we chose gold as a model substrate and studied a family of naphthalenebased additives. By using in-situ spectroscopy and density functional theory studies, we characterized the adsorption behavior of naphthalene-based additives as well as ethoxylated α-naphthalenesulfonic acid (ENSA-6), a commonly used additive in the tin electroplating industry, on well-defined gold surfaces, and discussed their correlation with the tin electrodeposition process.…”