The role of thiourea as an organic additive in the nucleation and growth mechanism was studied for copper deposition and its application in the decorative electroplating and fashion accessory industries. The bath was designed to reduce the environmental and ecological impacts using methanesulfonic acid as electrolyte as an alternative to alkaline cyanide baths. We evaluated the nucleation and growth mechanism of copper exploiting voltametric and chronoamperometric measurements with a brightener concentration ranging from 0 to 90 ppm. We used the Scharifker–Hills model to estimate the type of nucleation mechanism after progressive addition of thiourea. Scanning electron microscope was employed for surface analysis and morphological characterisation of the nuclei. We verified that progressive nucleation is a key step in the obtainment of a shiny and homogeneous copper film, but an excess of thiourea could cause parasitic adsorption reactions on the surface of the substrate. X-ray fluorescence spectroscopy was used for the thickness determination of the copper deposits and the electrodeposition efficiency correlated to thiourea concentration. Finally, the optimal concentration of thiourea was assessed to be 60 ppm for the used formulation of copper plating.

Oxygen Reduction Reaction (ORR) catalysts, from waste automobile tyres obtained from Microwave assisted pyrolysis (MAP), were enriched with Co and Cu using the simple treatments sonochemical and electrochemical deposition. Catalytic activity was evaluated through onset potential and number of exchanged electrons measurements. Electrochemical data demonstrate an improvement in catalytic activity of the electrochemical modified char with Co. Char electrodes enriched with Co show a maximum positive shift of 40 mV with respect to raw char electrodes with a number of exchanged electrons per O₂ molecule close to 4 (as for Pt) for the best sample. This corresponds to a reduction of the production of unwanted oxygen peroxide from 23% for raw char to 1%. Sample structure evolution before and after electrochemical deposition and electro-catalysis was investigated by scanning transmission electron microscopy and XPS. Such electrochemical treatments open new possibilities of refining waste chars and finding an economic alternative to noble metals-based catalysts for alkaline fuel cells.

In order to substitute traditional cyanide-based baths and obtain a new eco-compatible route to synthesize via electrodeposition a CZTS (copper-zinc-tin sulfide) absorber films, this paper describes the development of a green electrodeposition bath for Cu–Sn alloys. CZTS, being a p-type semiconducting material could be used in novel and sustainable photovoltaic devices. In this work we analyzed the electrochemical behavior of different methanesulfonic acid-based prototype deposition bath containing tin methanesulfonate as tin precursor, copper sulfate or methanesulfonate as copper precursor, and hydroquinone, nitrilotriacetic acid and 2-picolinic acid as organic additives. Electrodeposition was conducted with different deposition parameters such as deposition potential, current density, potentiostatic or galvanostatic mode. Surface and cross-section morphology as well as composition of the films were characterized using SEM-EDS. The composition of the samples in terms of crystalline phases was analyzed using XRD, highlighting the information obtained by superlattice diffraction peaks based on the crystallography of Cu–Sn intermetallic phases. From prototype bath S4 a uniform composition around Cu:Sn = 2:1 was observed with η ′ phase as the dominant phase, which could possibly facilitate the synthesis of CZTS due to its aligned body-center vacancies that could serve as sulfur diffusion path during sulfurization within each η ′ crystal.

This paper explores the conditions for the electrodeposition of Mo_ad (molybdenum adlayer) on Ag(111) from alkaline aqueous solution. Moreover, the first stages of the growth of MoSe₂ are also presented, performing the deposition of Se_ad on the deposited Mo_ad. The deposition of Mo_ad on Se_ad/Ag(111) was also explored. MoSe₂ is of interest due to its peculiar optoelectronic properties, making it suitable for solar energy conversion and nanoelectronics. In this study, electrodeposition techniques were exploited for the synthesis process as more sustainable alternatives to vacuum based techniques. The electrochemical atomic layer deposition (E-ALD) method emerges as a suitable technique to grow inorganic semiconductor thin films thanks to its fulfillment of the green energy predicament and a strict structural and morphological control, and this approach has gathered the attention of the scientific community. Indeed, E-ALD exploits surface limited reactions (SLRs) to alternate the deposition of chemically different atomic layers constituting a compound semiconductor. Thus, E-ALD is one of the most promising electrodeposition techniques for the growth of thin-film of compound semiconductors under a strict structural and morphological control. On this ground, E-ALD can be considered an ideal technique for the growth of 2D materials.

Various formulations for electroless deposition, to obtain continuous nanometre-sized and micrometre-sized films of palladium on copper, were compared. We deposited ultrathin films using displacement plating formulations. We obtained continuous films with an equivalent thickness between 6 and 22 nm, measured by exploiting the K-ratio method with SEM-EDS of Pd layers. The Pd films obtained in this step of the work represent a cost-effective catalytic substrate. As a second step, we selected chemical plating as the procedure to obtain palladium films with a thickness in the micrometre range. An ammonia-based Pd chemical plating bath represent one of the most effective chemical plating formulations. To prevent copper substrates from being damaged by ammonia, displacement plating with palladium was also applied as a pre-treatment to make the use of these plating baths a viable way to obtain thicker palladium coatings. Palladium films showing good adherence, compact morphology, and a thickness over 1.5 μm were obtained, proving that the combination of two different electroless techniques was the key to develop a sustainable procedure for micrometre-sized palladium coatings, which could substitute electroplating of Pd in galvanic industry for decorative applications.