Deposited Charge Density Research Articles

Influences of solvents and monomer concentrations on the electrochemical performance and structural properties of electrodeposited PEDOT films: a comparative study in water and acetonitrile.

Poly(3,4-ethylenedioxythiophene) (PEDOT) has emerged as a promising coating for neural electrodes especially through convenient electrodeposition methods. To investigate the influences of solvents and EDOT monomer concentrations on the electrochemical performance and structural characteristics of PEDOT, both aqueous and acetonitrile solutions were employed with varying monomer concentrations during deposition. The prepared PEDOT films were examined for the surface morphology, electrochemical performance, and chemical structures. The results showed that an increase in EDOT concentration in either solvent led to PEDOT films with improved charge storage capacity and reduced impedance magnitude. At equivalent monomer concentrations, PEDOT films generated in acetonitrile exhibited a rougher surface texture and better electrochemical performance. Notably, the growth rate of charge storage capacity of PEDOT prepared in acetonitrile relative to the deposited charge density was 2.5 times that of PEDOT prepared in water. These findings could help to the optimization of PEDOT coating preparation to enhance electrode performance.

Evaluating the ATR-SEIRAS performance of electrodeposited copper CO2 reduction catalysts using a flow-through spectroelectrochemical cell

The attenuated total reflection-surface-enhanced infrared absorption spectroscopy (SEIRAS) activity of electrodeposited Cu nanoparticles on indium tin oxide-modified Si internal reflection elements is reported. The solution in the cell is easily, and repeatedly, exchanged between a copper deposition bath and a solution containing 4-methoxypyridine through the use of a flow-through spectroelectrochemical cell. 4-methoxypyridine is a convenient SEIRAS probe molecule exhibiting potential-dependent adsorption/desorption on the copper surface. Successive amounts of copper are deposited and then evaluated for electrochemical SEIRAS activity without the need to expose the Cu surface to ambient conditions. It is found that copper deposition charge densities of approximately 60 mC cm−2 exhibit the largest amplitude and most symmetric IR absorption peaks of the investigated electrodeposition conditions. Scanning electron microscopy images of the different Cu charge density films are correlated with the SEIRAS results and establish that close-packed two-dimensional, percolated arrays of oblate, ellipsoidal Cu nanoparticles are responsible for ideal SEIRAS performance and three-dimensional aggregates of larger particles should be avoided. Textured films of Cu nanoparticles are used to determine the adsorbed species present on the copper surface during CO2 electroreduction at low overpotentials. Evidence of adsorbed CO and COH is found at lower overpotentials than those described in previous reports.

Channel charge density behind commonly used return stroke engineering model

The evolution characteristics behind the commonly used return stroke engineering model have not been fully understood, which limits the accurate estimation on the lightning damage effect. Therefore, the line charge densities behind the TL, MTLL MTLE, BG, TCS and DU models are discussed under three cases: (a) constant velocity with traditional attenuation function, (b) exponentially decreasing velocity with traditional attenuation function, and (c) exponentially decreasing velocity with improved attenuation function considering time factor. As height increases, the charge density behind the TL, MTLL and MTLE models in case (c) is between that in case (a) and (b). However, owing to the reduction of the inputting charge from the channel base and the gradually prominent deposition effect of the residual charge, the total charge densities in the three cases trend to be consistent with each other in the end. Additionally, the results suggest that the near-region radiated fields yielded by the traditional return stroke model (case (a)) may be smaller than the actual observation. For the BG, TCS and DU models, the connotative charge density is mainly the deposited charge density component. Although the charge density decreases overall with height, the waveform exhibits a “hump” at the height of about 2 km∼3 km. The presented results may be of assistance in understanding the commonly used engineering model, as well as in performing more effective protection against lightning hazards.

Solvent dielectric effect on electrochemical properties of 3,4-propylenedioxythiophene

The present study is focused on the electrochemical properties of poly(3,4-propylene­dioxy­thiophene) (Poly(ProDOT)), electrocoated on the single carbon-fiber microelectrode (SCFME) in different electrolytic media, with different solvent dielectric constants (35.9, 41.7, 47.5, 53.3, 59.1 and 64.9). The highest deposition charge density of 24.49 mC cm-2 and the highest specific capacitance of 23.17 mF cm-2 were obtained for Poly(ProDOT) synthesized in a medium with the lowest solvent dielectric constant (e = 35.9). Electrochemical impedance spectroscopy (EIS) results of Poly(ProDOT) coated SCFME measured at open circuit potential showed continuously increased impedance magnitudes as ε was increased from 35.9 to 59.1. For all films, almost capacitive impedance responses at lower frequencies at least were obtained. The highest capacitance was observed for the polymer film synthesized in the medium of e = 35.9. The impedance of this film was also measured in different solvent mixtures with different dielectric constants at open circuit potential.

Superior galvanostatic electrochemical deposition of platinum nanograss provides high performance planar microelectrodes for in vitro neural recording

Objective. Platinum nanograss (Ptng) has been demonstrated as an excellent coating to increase the electrode roughness and reduce the impedance of microelectrodes for neural recording. However, the optimisation of the original potentiostatic electrochemical deposition (PSED) method has been performed by the original group only and no in vitro validation of functionality was reported. Approach. This study firstly reinvestigates the use of the PSED method for Ptng coating at different charge densities which highlights non-uniformities in the edges of the microelectrodes for increasing deposition charge densities, leading to a decreased impedance which is in fact an artefact. We then introduce a novel Ptng fabrication method of galvanostatic electrochemical deposition (GSED). Main results. We demonstrate that the GSED deposition method also significantly reduces the electrode impedance, raises the charge storage capacity and provides a significantly more planar electrode surface in comparison to the PSED method with negligible edge effects. In addition, we demonstrate how high-quality neural recordings were performed, for the first time, using the Ptng GSED deposition microelectrodes from human hNT neurons and how spiking and bursting were observed. Significance. Thus, the GSED Ptng deposition method presented here provides an alternative method of microelectrode fabrication for neural applications with excellent impedance and planarity of surface.

A highly efficient faradaic desalination system utilizing MnO2 and polypyrrole-coated titanium electrodes

A highly efficient pseudocapacitive desalination system is constructed with positive MnO2 and negative polypyrrole electrodes. Both materials deposited by electrochemical methods exhibit faradaic reactions with the “memory effect” and permit the unique multi-function application with salt-removing and concentrating abilities. The quasi-steady state electrode potentials of both electrodes under charged/discharged states and the cell salt removal capacity (SRC) highly depends on the mass loading of active materials. To ensure the quasi-steady state electrode potentials of materials in their working potential windows, the mass loadings of active materials are carefully controlled by the deposition charge density. After the mass loading adjustment, SRC reaches 78 mg g−1 in a 60-min salt-removing process. The salt removal rate (SRR) reaches the highest value of ca. 5 mg g−1 min−1 during the initial 5 min and continuously decreases to near 0 with prolonging the desalination time. In the stability test, this MnO2//PPy cell remains over 90% of its original SRC in a 100-cycle test. Shortening the time of a single operation segment is an efficient way to increase the average SRR which reaches 212.7 mg g−1 in this MnO2//PPy cell transferring NaCl from one solution to another in a 120-min test using the 4/4-min model.

Investigation of electrochemical deposition of Fe-P alloys on polycrystalline platinum from an alkaline bath

The electrodeposition process of the Fe-P alloy on platinum substrate was investigated at room temperature using a moderately alkaline bath containing FeCl3, NaH2PO2 and Na3NTA (trisodium nitrilotriacetate), which stabilized the Fe(III) ions in the bath at pH 8.0. Cyclic voltammetry was used to analyze the electrochemical behavior of the Fe(III)-NTA species in the electrodeposition bath, and two cathodic and two anodic processes were found. Hydrodynamic studies suggested that the reduction processes are mainly controlled by mass transport. Energy dispersive X-ray spectrometry analysis showed that Fe and P co-deposited. Scanning electron microscopy micrographs revealed electrodeposits without cracks or dendritic crystallites. The Fe and Fe3P phases could be observed by X-ray diffraction in the Fe-P electrodeposits produced from alkaline NTA bath. Confocal laser scanning microscopy showed that roughness of Fe-P electrodeposits, produced with deposition charge density of 40.0 C cm−2, decreased from 0.046 µm to 0.024 µm, depending on the deposition potential.

Optimization of low value electrodeposition parameters of nano-structured NiO electrochromic thin films

In this work, the electrochromic and structural properties of NiO thin films prepared using optimized low value electrodeposition parameters were studied. The optimized parameters were deposition current density, molar concentration of nickel nitrate solution, and deposited charge density. The highest electrochromic characteristics corresponded to deposition parameters of −0.05 mA/cm2 deposition current density, 0.02 M of Ni(NO3)2.6H2O solution, and charge density of 80 mC/cm2. For this optimized film, at 630 nm wavelength, the transmittance modulation ΔT was 76%, the efficiency η was 19 cm2/C, the charge reversibility Qc/Qa was 97%, and a remarkable contrast ratio CR of 5.9. In addition, a good cycling stability was confirmed up to 900 cycles. Optimized NiO thin films were poorly crystallized exhibiting a nano-flake structure, high porosity, and homogeneity.

Charge Carrier Dynamics in Metal-Oxide/Nanocarbon Hybrid Photoelectrodes

One of the most critical challenges of the 21st century is the shift in energy use from fossil fuels to renewable sources. Photoelectrochemical solar energy conversion, as a potentially attractive candidate, has gained an increased momentum during the recent years. Although both water-splitting (hydrogen evolution) and carbon dioxide reduction are promising avenues, they both have substantial shortcomings to be addressed. A common virtue of these two processes is that a good photoelectrode has to concurrently fulfill many attributes to drive these reactions efficiently. One of the most important is the efficient charge carrier transport, which ensures that most of the photogenerated charge carriers can be extracted both toward the electrode/electrolyte junction and toward the back contact. Numerous promising photoelectrode material showed poor performance due to extensive charge carrier recombination both in the bulk and at the surface. A well-known example is α-Fe2O3 (hematite), in which the hole-diffusion length is only 2-4 nm.1 One possible way to improve charge carrier transport properties is to deposit the metal-oxide on an interconnected nanocarbon network (e.g., carbon nanotubes or graphene). These highly conductive nanoscaffolds can improve the transport of the photogenerated charge carriers, which in turn, results in an enhanced photoelectrochemical performance.2 In my presentation, I am going to discuss how charge carrier dynamics of various hematite and hematite/nanocarbon composites is affected by the composition of the nanohybrids and by the applied bias. Hematite/nanocarbon photoelectrodes were synthesized by a two-step method: first the nanocarbon layer was spray-coated on the surface of the substrate electrode, and the nanostructured metal-oxide component was electrodeposited in a subsequent step. The metal-oxide/nanocarbon ratio was precisely controlled by the deposition charge density. To investigate charge carrier dynamics on a timescale ranging from seconds to femtoseconds three different techniques were employed: (i) transient absorption spectroscopy, employing a fs pump-probe setup, (ii) intensity-modulated photocurrent spectroscopy, and finally (iii) fast chronoamperometry. By covering this broad timescale, it was possible to study charge carrier transport, trapping and recombination processes, which were greatly affected by both the applied potential and the presence of the nanocarbons. 1 Energy Environ. Sci., 2016, 9, 2744—2775. 2 J. Am. Chem. Soc. 2017, 139, 6682−6692.

Morphology-dependent mass transport model for mechanoelectrochemistry of polypyrrole

Conducting polymers undergo volumetric deformations due to ingress/egress of counter-ions and solvent molecules during electrochemical reduction/oxidation. A precise measurement of volumetric deformations (as extensional strain) has been elusive due to lack of experimental methods and hence, different mathematical models make simplifying assumptions in attributing the strain to various transported species. Recently, an investigation into static and dynamic mechanoelectrochemistry of polypyrrole doped with dodecylbenzenesulfonate (PPy(DBS)) has provided morphology-dependent strain data for PPy(DBS) and can be used to precisely attribute volumetric strain of PPy(DBS) to various components that move into and out of the polymer. To address the longstanding need for a mass transport based mechanics model, we present a morphology-dependent mathematical framework that attributes the strain during electrochemical reduction/oxidation of PPy(DBS) to cations and solvent (water) molecules. This model builds upon a chemomechanical constitutive model for conducting polymers and combines it with measured strain to derive fundamental structure-property-function relationships in PPy(DBS). The polymer’s morphology is represented by macroscopic porosity in the oxidized state and it is observed that the porosity of the polymer in the oxidized state decreases linearly with electrochemical deposition charge density (C cm−2). The osmotic pressure due to ion and water transport is found to be inversely proportional to porosity of the polymer, and number of water molecules transported appear to be governed by the interplay between osmotic pressure and compliance of the film. These results are anticipated to serve as guidelines in the design of robust biomedical devices and energy storage materials using PPy(DBS) and other conducting polymers in aqueous/organic solvents.

Low-Loading of Pt Nanoparticles on 3D Carbon Foam Support for Highly Active and Stable Hydrogen Production.

Minimizing Pt loading is essential for designing cost-effective water electrolyzers and fuel cell systems. Recently, three-dimensional macroporous open-pore electroactive supports have been widely regarded as promising architectures to lower loading amounts of Pt because of its large surface area, easy electrolyte access to Pt sites, and superior gas diffusion properties to accelerate diffusion of H2 bubbles from the Pt surface. However, studies to date have mainly focused on Pt loading on Ni-based 3D open pore supports which are prone to corrosion in highly acidic and alkaline conditions. Here, we investigate electrodeposition of Pt nanoparticles in low-loading amounts on commercially available, inexpensive, 3D carbon foam (CF) support and benchmark their activity and stability for electrolytic hydrogen production. We first elucidate the effect of deposition potential on the Pt nanoparticle size, density and subsequently its coverage on 3D CF. Analysis of the Pt deposit using scanning electron microscopy images reveal that for a given deposition charge density, the particle density increases (with cubic power) and particle size decreases (linearly) with deposition overpotential. A deposition potential of −0.4 V vs. standard calomel electrode (SCE) provided the highest Pt nanoparticle coverage on 3D CF surface. Different loading amounts of Pt (0.0075–0.1 mgPt/cm2) was then deposited on CF at −0.4 V vs. SCE and subsequently studied for its hydrogen evolution reaction (HER) activity in acidic 1M H2SO4 electrolyte. The Pt/CF catalyst with loading amounts as low as 0.06 mgPt/cm2 (10-fold lower than state-of-the-art commercial electrodes) demonstrated a mass activity of 2.6 ampere per milligram Pt at 200 mV overpotential, nearly 6-fold greater than the commercial Pt/C catalyst tested under similar conditions. The 3D architectured electrode also demonstrated excellent stability, showing <7% loss in activity after 60 h of constant current water electrolysis at 100 mA/cm2.

The influence of macropores on PEDOT/PSS microelectrode coatings for neuronal recording and stimulation

Recent trends towards smaller electrodes for improved spatial resolution have seen the rise of rough electrode coatings, such as conducting polymer (CPs), to increase electrochemical surface area and subsequently recording and stimulation performance. Here, we directly compare the influence of macropores in poly(3,4-ethylenedioxythiophene)/polystyrene sulphonate (PEDOT/PSS) coatings hypothesised to further increase electrochemical surface area and gain new insights into the influence of surface morphology on CP signal transduction. Macroporous PEDOT/PSS polymerised at the highest charge density of 637 mC cm−2 displayed significant reductions in impedance magnitude (at 100 Hz) and thermal noise and significant increases in the charge injection limit when compared to untemplated PEDOT/PSS. Macroporous PEDOT/PSS was more susceptible to delamination following long-term biphasic stimulation, however, it displayed an interesting improvement in impedance throughout the experiment. Biocompatibility of both untemplated and macroporous PEDOT/PSS coatings alongside primary hippocampal neurons in-vitro was demonstrated via neuronal viability assays. Improvements were noted in electrochemical properties achieved by the macroporous coatings, meanwhile in-vitro recording and stimulation performance favoured untemplated PEDOT/PSS as measured through signal-to-noise ratios and direct neuronal responses to biphasic stimuli, respectively. Whilst the macroporous structures perform similarly to untemplated PEDOT/PSS in-vitro, the significant improvement in their electrochemical surface area at high deposition charge densities may offer them use in fields of drug delivery and biosensing.

A charging method for electrets based on interfacial polarization

A charging method for electrets is proposed, based on interfacial polarization in double-layer media. It can achieve a high density and excellent stability of the charge storage as well as good uniformity of the surface potential distribution on electret materials. An equation for the charge accumulation at the interface of double-layer dielectrics is derived. FEP film electrets are successfully obtained by means of this charging method with an auxiliary PP-layer. The effect of the charging voltage on the storage performance shows that the surface potential of FEP films increases linearly with the charging voltage. This is in good agreement with the theoretical analysis. The effect of the charging temperature is ascribed to the change in conductivity of the two dielectrics, whereby the current density in particular across the PP layer increases with a rise in charging temperature. In addition, the charge is captured by deeper traps, while the deposition charge density increases.

Conducting polymer microcontainers for biomedical applications.

Advancement in the development of metallic-based implantable micro-scale bioelectronics has been limited by low signal to noise ratios and low charge injection at electrode-tissue interfaces. Further, implantable electrodes lose their long-term functionality because of unfavorable reactive tissue responses. Thus, substantial incentive exists to produce bioelectronics capable of delivering therapeutic compounds while improving electrical performance. Here, we have produced hollow poly(pyrrole) microcontainers (MCs) using poly(lactic-co-glycolic) acid (PLGA) as degradable templates. We demonstrate that the effective surface area of the electrode increases significantly as deposition charge density is increased, resulting in a 91% decrease in impedance and an 85% increase in charge storage capacity versus uncoated gold electrodes. We also developed an equivalent circuit model to quantify the effect of conducting polymer film growth on impedance. These MC-modified electrodes offer the potential to improve the electrical properties of implantable bioelectronics, as well as provide potential controlled release avenues for drug delivery applications.

Tuning Ag morphology on TiO2 nanotube arrays by pulse reverse current deposition for enhanced plasmon-driven visible-light response

TiO2 nanotube arrays (NTAs) decorated with controllable Ag particles were prepared by pulse reverse current deposition in AgNO3/NaNO3 aqueous solution, aiming to improve the photoelectrochemical properties of TiO2 NTA electrode in visible-light region. By tuning the pulse current density and deposited charge density, a controllable synthesis of Ag structures was achieved. Excellent photocurrent responses of TiO2 NTAs in UV and visible light regions were achieved by depositing Ag nanorods and nanoparticles, which was attributed to highly efficient charge separation by the Schottky junction at the Ag/TiO2 interface and localized surface plasmon resonance effect of Ag nanostructures.

Electrodeposition of CuZn films from free-of-cyanide alkaline baths containing EDTA as complexing agent

Abstract In order to study alternative complexing agents for cyanide in Cu–Zn electrodeposition, electrodeposits from cyanide-free alkaline baths containing EDTA as complexing agent were analyzed. The electrodeposition was carried out under constant current conditions (galvanostatic) on AISI 1010 steel substrates. Electrodeposition process and the deposits were characterized with surface morphological analyses, stripping anodic voltammetries, chemical composition and X-ray diffraction (XRD) analysis. Current efficiencies (CEs) higher than 90% for Cu–Zn electrodeposition were obtained at low deposition current densities (j dep ) for baths with the highest molar [Cu 2 + ]/[Zn 2 + ] ratio in solution (70/30). For higher j dep , smaller CEs were obtained. By scanning electron microscopy, fine-grained deposits were observed at j dep of − 4.0 and − 10.0 mA cm − 2 for deposition charge densities (q dep ) of 2 and 10 C cm − 2 and for j dep of − 20 mA cm − 2 only for 2 C cm − 2 in the analyzed range of j dep and q dep . Continuous deposits free of cracks were obtained. Colors of deposits such as: bright golden and dark brown could be obtained, depending on j dep and q dep . Burning of deposits was observed at j dep of − 80 mA cm − 2 at high q dep . Semi-quantitative chemical analyses of deposits from Cu70Zn30 baths indicated richer in copper deposits. By XRD analysis CuZn 2 , Cu 0.61 Zn 0.39 , Cu and CuO were detected and no inclusions of ZnO. EDTA has prospects for substituting cyanide, however in a limited range of j dep and q dep .

Correlation of phase resolved current, emission and surface charge measurements in an atmospheric pressure helium jet

The interaction of an atmospheric pressure plasma jet with two different surfaces (conducting and dielectric) is investigated using a setup with two ring electrodes around a dielectric capillary. For diagnostics, phase resolved ICCD-imaging, current measurements and surface charge measurements are applied. The results show the correlation of plasma dynamics with the deposition of surface charge and electrical current signals. Further, the influence of the distance between surface and jet capillary on the surface charge distribution is presented. A complex discharge dynamic is found with a dielectric barrier discharge between the ring electrodes and back-and-forth bullet propagation outside the capillary. A conducting channel connecting the jet nozzle and the surface is found. This correlates well with the observed charge exchange on the surface. The number of formed channels and the average deposited charge density on the surface is found to be strongly sensitive to the jet distance from the surface.

Copper–zinc electrodeposition in alkaline-sorbitol medium: Electrochemical studies and structural, morphological and chemical composition characterization

The galvanostatic technique was used to analyze the electrodeposition of Cu–Zn on to AISI 1010 steel electrode from an alkaline-sorbitol bath with various proportions of the metal ions in the bath: Cu70/Zn30, Cu50/Zn50 and Cu30/Zn70. Coloration of Cu–Zn films were whitish golden, light golden, golden/gray depending on the Cu2+/Zn2+ ratios in the electrodeposition bath, deposition current density (jdep) and charge density (qdep). The highest current efficiency was ∼54.0%, at jdep −1.0mAcm−2 and qdep 0.40Ccm−2 in the Cu70/Zn30 bath. Energy dispersive spectroscopy indicated that electrodeposits produced from the bath Cu70/Zn30 showed higher Cu content at lower jdep. Also, for same jdep the Cu content increased with qdep. Scanning electron microscopy showed that Cu–Zn electrodeposits of high quality were obtained from the Cu70/Zn30 bath, since the films were fine-grained, except the obtained at jdep −20.0mAcm−2 and qdep 10.0Ccm−2. Also, these electrodeposits did not present cracks. X-ray analysis of the Cu–Zn electrodeposits obtained at jdep −8.0, −20.0 and −40.0mAcm−2, in each case, with qdep 2.0 and 10.0Ccm−2, in the Cu70/Zn30 bath, suggested the occurrence of a mixture of the following phases, CuZn, CuZn5 and Cu5Zn8. Galvanostatic electrodeposits of Cu–Zn obtained from sorbitol-alkaline baths exhibited whitish golden color, with good prospects for industrial applications, especially for decorative purposes.

Tin Dioxide Functionalized Single-Walled Carbon Nanotube (SnO2/SWNT)-Based Ammonia Gas Sensors and Their Sensing Mechanism

Tin oxide functionalized single-walled carbon nanotubes (SWNTs) were synthesized on prefabricated microelectrodes by an electrochemical process. The shape, morphology, valence state and crystal structure of tin oxide were controlled by varying the deposition potential (E), charge density (C), and subsequent calcining temperature (T) and their structure-related sensing performance toward ammonia (NH3) gas was characterized at 25°C. Optimal sensing performance was obtained under the conditions of E = −0.625 V, C = 0.125 C/cm2, T = 400°C. The underlying NH3 sensing mechanisms of the SnO2/SWNTs hybrid nanostructures were studied, indicating that the higher Sn2+ dopants in SnO2 (obtained at a higher applied potential of −0.625 V) in the oxides as well as the greater active surface area (obtained at the optimal charge density of 0.125 C/cm2) and the lowest calcining temperature of 400°C are the key factors in improving the sensing performance. Selectivity of the gas sensors was determined by exposing them to CO and NO2 at room temperature.

Copper–tin electrodeposition from an acid solution containing EDTA added

An acid Cu–Sn deposition bath was developed, containing EDTA (disodium ethylenediaminetetraacetate) to sequester the copper(II) and tin(II) ions, forming stable complexes in solution at pH3.4. Voltammetric studies showed that the onset of Cu–Sn codeposition started with reduction of [CuEDTA]2− and [Sn(H2O)6]2+ at potential more negative than −0.90V (first region of deposition). The reduction of [SnEDTA]2− complexes occurs at potential more negative than −1.20V (second region of deposition), leading to Cu–Sn alloys with a higher tin content. The hydrogen evolution reaction (HER) occurs in all range of potential parallel to the Cu–Sn deposition. No nucleation loop was observed in the voltammetric curves for Cu–Sn deposition due to HER. Cu–Sn voltammetric deposition at various sweep rates indicated that the deposition process may be controlled by mass transport and charge transfer in both regions. The Sn content in the potentiostatic Cu–Sn (Ed) change, from ~27.0wt.% to ~60.0wt.%, for a constant composition of deposition bath. Cu–Sn deposit containing 43.6wt.% Sn was obtained from the acid EDTA bath investigated herein. The color of the deposits was reddish (~27.0wt.% Sn) and grayish (~32.0wt.% –~60.0wt.% Sn).Scanning electron microscopy images showed that the deposits produced at −1.03V and −1.30V, for both deposition charge densities (qd), 2.55Ccm−2 and 8.47Ccm−2, were composed of cauliflower-like particles, which increased with qd, and that the deposits obtained at −1.30V were more compact than those formed at −1.03V, for both qd, being this, the main difference between these two types of deposits.X-ray patterns of the deposits formed at Ed=−1.03V, with either qd, using non-grazing incidence, indicated the presence of hcp-CuSn and Cu3Sn phases. However, for Ed=−1.30V were identified the Cu6Sn5 and Cu10Sn3 phases for qd=2.55Ccm−2 and only Cu6Sn5 phase for qd=8.47Ccm−2.