The present work follows the trend to develop non-aqueous electrolytes for the deposition of corrosion resistant ZnNi alloys. It investigates the use of the choline chloride/ethylene glycol (1:2 ...molar ratio) eutectic mixture and of pure ethylene glycol as solvents for ZnNi electroplating. The electrochemical behavior of Zn and Ni is investigated via cyclic voltammetry, and potentiostatic ZnNi deposition is performed. Ni content is found to be precisely tunable in the 10–20% wt range, which presents the highest industrial interest for corrosion protection. ZnNi coatings obtained are characterized from the morphological and phase composition point of view. Evidence of the formation of a metastable γ ZnNi phase is observed for both choline chloride/ethylene glycol and pure ethylene glycol. Finally, potentiodynamic corrosion tests are performed to assess their corrosion properties.
► Deep Eutectic solvent (1 choline chloride: 2 urea mixture) is useful to attain Co, Sm, and SmCo electrodeposition. ► Co deposition proceeds by nucleation and three dimensional growth. ► Inhibition ...for Sm deposition was detected. ► Influence of metals concentration was observed on Sm:Co ratio.
The suitability of 1 choline chloride:2 urea mixture, Deep Eutectic Solvent (DES) for the electrodeposition of cobalt, samarium and cobalt–samarium system has been studied. Its electrochemical window permits deposition analysis to be carried out without interference from parallel reactions. Deposition was studied at 70°C in order to stimulate mass transfer and to lower solution viscosity.
Cobalt deposits according to a nucleation and three dimensional growth mechanism, all its characteristic features do appear for all cases studied. Samarium deposition takes place through a more complex process in which a first potential range is found where the species formed limit the conductive character of the substrate. When potential becomes more negative, normal behaviour is observed. When both cobalt and samarium are present in the solution, codeposition occurs, at no potential value, any current diminution of the current was recorded under stirred conditions. Deposits of SmCo show different morphology and composition depending on applied potential. Nodular cobalt-rich deposits are obtained at low deposition potentials whereas fine grained samarium-rich ones are obtained at more negative deposition potentials.
Abstract
In this work, a three-layered heterostructure Cu
2
O/CuO/CuS was obtained through a low-cost and large-area fabrication route comprising electrodeposition, thermal oxidation, and reactive ...annealing in a sulfur atmosphere. Morphological, microstructural, and compositional analysis (AFM, SEM, XRD, EDS, XPS) were carried out to highlight the surface modification of cuprous oxide film after oxidation and subsequent sulfurization. Impedance, voltammetric, and amperometric photoelectrochemical tests were performed on Cu
2
O, Cu
2
O/CuO, and Cu
2
O/CuO/CuS photocathodes in a sodium sulfate solution (pH 5), under 100 mW cm
−2
AM 1.5 G illumination. A progressive improvement in terms of photocurrent and stability was observed after oxidation and sulfurization treatments, reaching a maximum of − 1.38 mA cm
−2
at 0 V versus RHE for the CuS-modified Cu
2
O/CuO electrode, corresponding to a ~ 30% improvement. The feasibility of the proposed method was demonstrated through the fabrication of a large area photoelectrode of 10 cm
2
, showing no significant differences in characteristics if compared to a small area photoelectrode of 1 cm
2
.
In the present paper the electroless metallization of 3D printed devices using stereolithography is investigated. Two different photocurable resins from a commercial supplier and a self-formulated ...one are used as starting materials for printing. A first metal layer of NiP or Cu, obtained by an optimized pretreatment and plating process, is subsequently applied on the parts. The possibility of obtaining multilayers through the successive electrodeposition of different metals on the electroless treated parts is demonstrated as well. From the applicative point of view, the use of 3D printing, coupled with electroless deposition of mono or multilayers, can be employed to manufacture functional microstructures for use in the fields of microrobotics, MEMS, metamaterials and others. For this reason, the realization of a prototypical magnetic actuator is presented as an example of possible application.
The availability of low cost, efficient and wearable glucose sensors is one of the prerequisites for the development of ubiquitous sensors networks for the efficient monitoring of diabetes ...epidemiology. Starting from this principle, wet metallization and low cost inkjet printing were employed in the present work to manufacture non-enzymatic electrochemical sensors. CuO nanoparticles were inkjet printed on platinum, which was electrodeposited on stainless steel. The active layer obtained in this way showed an acceptable linear range for glucose detection and a good sensitivity when used as sensor. The influence on performances of interfering species and curvature were investigated, demonstrating a negligible effect for the first and a decrease in linearity of the response and sensitivity for the latter.
Controlled SU-8 inkjet printing constitutes an attractive approach to realize electronic microstructures, MEMS, microfluidic devices or transducers. Indeed, inkjet printing is the most promising ...low-cost manufacturing process capable of depositing functional materials with high resolution, making this technique attractive for micrometric patterning. On the base of these premises, it's here presented the possibility to successfully print SU-8 complex patterned structures. Indeed, two different diluted SU-8 mixtures are successfully printed and a deep analysis on the effect of the physical parameters of the solvent is presented. The main challenges in SU-8 inkjet patterning are individuated and discussed through the evaluation of different shapes presenting critical printing aspects. In addition, some possible approaches to address such challenges are presented. Finally, the possibility to use inkjet printed SU-8 masks as templates for metal electrodeposition is demonstrated.
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•Continuous SU-8 patterns were obtained employing inkjet printing.•Four main challenges related to SU-8 inkjet patterning were identified.•Possible approaches to address patterning challenges were provided.•Performances of SU-8 patterning were demonstrated by printing different test shapes.•Printing of templates for metal patterning via electrodeposition was demonstrated.
In this work, the electrodeposition of zinc is carried out from a chlorides-free organic solution based on ethylene glycol (EG) and acetate precursor salts. The formation of an EG-complex with zinc ...was observed through 1H NMR. The electrochemical characterization was performed by means of cyclic voltammetry (CV) and linear sweep voltammetry (LSV) on platinum and steel respectively. Electrodeposition was investigated with both potentiostatic (from −1 V vs Pt to −2 V vs Pt) and galvanostatic (from −2 mA/cm2 to −16 mA/cm2) approaches together with Hull cell test: cathodic efficiencies > 85% were reported. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses showed that the films were compact, with large grains and a hexagonal microstructure preferentially oriented along the 002/102 directions. The high purity of the deposits was assessed by electron dispersive spectroscopy (EDS). Polarization tests in de-aerated 5 %wt NaCl solution resulted in a corrosion potential of Ecorr = −1.03 V vs Ag/AgCl (Icorr = 1.01 × 10−6 A/cm2).
A Deep Eutectic Solvent of 1 chlorine chloride: 2 urea eutectic mixture at 70
°C has been tested as useful to electrodeposit both magnetic SmCo films and nanowires. Galvanostatic deposition allows ...obtaining homogeneous deposits over metallic substrate with variable composition as a function of the current density applied. The deposits obtained at 0.5–1.5
mA
cm
−
2
were uniform and they correspond to a cobalt hexagonal crystalline phase with magnetic anisotropy and coercivity of 250
Oe. It has been possible to deposit SmCo nanowires from the DES solvent using alumina templates. Uniform CoSm nanowires of 50
nm of diameter have been obtained; they correspond also to hexagonal phase, but they present higher coercivity.
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► Electrodeposition of alloys containing earth metals by using Deep Eutectic Solvent. ► Preparation of SmCo magnetic films of modulate composition over metallic substrate. ► SmCo nanowires (diameter: 50
nm, several microns thick) have been obtained from DES.
Electroless nickel and copper metallization of 3D printed polymers like polylactic acid and polyethylene terephthalate glycol modified is presented. The plating process is tested on suitable samples, ...which reproduce the characteristic morphologies used in 3D printing of objects. An alkaline etching is used for both polymers in order to modify the surface properties and to enhance the adhesion and uniformity of the metallic coating. In the case of polylactic acid, a plasma treatment is applied as well to further improve adhesion of the metallic coating. For the activation of the surface, a tin free process involving an immersion in a palladium solution and subsequent reduction to form metallic nuclei is employed. Electrolytes are formulated and selected to operate in temperature ranges comparable with the glass transition temperatures of the polymers. Adherent and uniform layers of NiP (3-4% P wt) and Cu can be easily obtained for esthetic and functional applications, also on flexible substrates.
Earth-abundant and non-toxic Kesterite-based Cu
2
ZnSnS
4
(CZTS) thin film solar cells are successfully fabricated on flexible Molybdenum (Mo) foil substrates by an electrodeposition-annealing route. ...A well-adherent, densely packed, homogeneous, compact, and mirror-like CZT precursor is initially produced through electrodeposition by using a rotating working electrode. Subsequently, the co-electrodeposited CuZnSn (CZT) precursor is sulfurized in quartz tube furnace at 550 °C for 2 h in N
2
atmosphere with the presence of elemental sulfur in order to form CZTS. Different characterization techniques like XRD, SEM, HR-TEM, Raman, and Photoluminescence demonstrate that almost phase-pure CZTS formed after sulfurization. A flexible Al/Al-ZnO/i-ZnO/CdS/CZTS/Mo foil solar cell is produced, where CdS is deposited by chemical bath deposition and transparent conducting oxide (TCO) is deposited by DC sputtering. The CZTS solar device shows a 0.55% power conversion efficiency on flexible Mo foil substrate and it constitutes the first prototype of this kind of solar cell produced by electrodeposition-annealing route without any surface modification of the Mo substrate.
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