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1

The use of ionic liquid analogues in the electrodeposition of Ni/Graphene composite coatings as electrocatalytically active materials

Leszczak Klara, Niciejewska Anna, Laszczyńska Agnieszka, Winiarski Juliusz

Ochrona przed Korozją

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2025

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nr 12

352--357

EN

Ni/Graphene composite coatings were obtained potentiostatically in deep eutectic solvent (DES) composed of choline chloride and propylene glycol with dispersed graphene flakes, as electrode materials for hydrogen production in alkaline electrolysis. The hydrogen evolution reaction on Ni/Graphene coatings in 1 mol/dm3 KOH follows the coupled Volmer-Heyrovsky mechanism. The composite coatings were characterized by a lower overpotential value (93–99 mV/dec) than the raw Ni (109 mV/dec). EIS at −0.157 V vs RHE indicates a capacitive nature of the system and activation control of the charge transfer at the coating-electrolyte interface. However, at −0.257 V vs RHE an induction loop appeared, indicating the presence of hydrogen gas bubble adsorption. The double layer capacitance and the real surface area were higher for the coatings obtained from a bath containing graphene, especially at 0.2 g/dm3. Unfortunately, the intrinsic electrocatalytic activity of Ni/Graphene materials decreases, not allowing them to achieve such good activity as for raw Ni deposited in DES.

PL

W nanodyspersyjnej kąpieli galwanicznej zawierającej rozpuszczalnik eutektyczny (DES) złożony z chlorku choliny i glikolu propylenowego oraz grafenu, otrzymano potencjostatycznie powłoki kompozytowe Ni/Grafen, jako materiały elektrodowe do wytwarzania wodoru w procesie elektrolizy alkalicznej. Reakcja wydzielania wodoru na powłokach Ni/Grafen w 1 mol/dm3 KOH przebiega zgodnie ze sprzężonym mecha nizmem Volmera-Heyrowskiego. Powłoki kompozytowe charak te ry zowały się niższą wartością nadpotencjału (93–99 mV/dec) niż po włoka Ni (109 mV/dec). Widma impedancji zarejestrowane przy –0,157 V wzgl. RHE wskazują na typowo pojemnościową naturę układu i kontrolę aktywacyjną reakcji przeniesienia ładunku na granicy powłoka-elektrolit. Jednakże przy –0,257 V wzgl. RHE pojawia się pętla indukcyjna przy naj niższych częstotliwościach, co wskazuje na adsorpcję pęche rzyków gazowego wodoru na powierzchni elektrody. Pojemność warstwy podwójnej i rzeczywista powierzchnia były zdecydowanie wyższe dla powłok otrzymanych z kąpieli zawierającej grafen, szczególnie przy 0,2 g/dm3. Niestety, wewnętrzna aktywność elektrokatalityczna materiałów Ni/Grafen maleje i nie pozwala na osiągnięcie tak dobrych właś ciwości elektrokatalitycznych jak w przy padku Ni otrzymanego w DES.

2

Improvement of the corrosion behaviour of mild steel by deposition of Zn–Ni–Cu–Fe–Cd from an acetate sulphate bath

Evecen Meryem, Alfalah Mothana Ghazi, Saracoglu Murat, Kandemirli Fatma

Ochrona przed Korozją

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2025

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nr 2

41--47

PL

Pięcioskładnikowy stop Zn–Ni–Cu–Fe–Cd został osadzony elektrolitycznie na stali miękkiej w kąpieli octanowo-siarczanowej z zastosowaniem tylko potencjału katodowego w woltamperometrii liniowej. Zbadano wpływ szybkości skanowania (1 mV/s, 5 mV/s, 10 mV/s), a także wpływ dodatków organicznych: 4-(4-nitrofenylo)-3-tiosemikarbazyd lub 4-(3-metoksyfenylo)-3-tiosemikarbazyd, na wygląd powierzchni i skład osadzanej powłoki. Do zbadania zachowania korozyjnego stopu po zanurzeniu w roztworze zawierającym 1 M HCl wykorzystano trzy techniki elektrochemiczne: polaryzację potencjodynamiczną (PDP), polaryzację liniową (LPR) i elektrochemiczną spektroskopię impedancyjną (EIS). Po osadzeniu przeprowadzono analizę za pomocą spektroskopii rentgenowskiej z dyspersją energii (EDX) i skaningowej mikroskopii elektronowej (SEM), aby wizualnie ocenić powłoki. Najniższą gęstość prądu korozyjnego, najwyższą odporność na korozję i najwyższą impedancję zaobserwowano w każdym układzie stopowym przy szybkości skanowania wynoszącej 1 mV/s. Wartości te wynosiły odpowiednio: 67 μA/cm−2, 51 μA/cm−2 i 7,6 μA/cm−2 dla PDP, 965 Ω · cm2, 1117 Ω · cm2 i 2853 Ω · cm2 dla LPR oraz 1602 Ω · cm2, 12 938 Ω · cm2 i 1595 Ω · cm2 dla EIS, co odpowiadało kolejno: powłokom bez dodatków, powłokom z dodatkiem 4-(4-nitrofenylo)-3-tiosemikarbazydu i powłokom z dodatkiem 4-(3-metoksyfenylo)-3-tiosemikarbazydu. Na podstawie wyników badań SEM i EDX stwierdzono, że 4-(3-metoksyfenylo)-3-tiosemikarbazyd ma większy wpływ na powłokę niż 4-(4-nitrofenylo)-3-tiosemikarbazyd, prawdopodobnie ze względu na jego lepszą adsorpcję na powierzchni miękkiej stali.

EN

Zn–Ni–Cu–Fe–Cd quinary alloy was successfully electrodeposited on mild steel from acetate-sulphate baths with only cathodic potential applied during linear sweep voltammetry. The influence of scan rate (1 mV/s, 5 mV/s and 10 mV/s) as well as the effect of organic additives: 4-(4-nitrophenyl)-3-thiosemicarbazide or 4-(3-methoxyphenyl)-3-thiosemicarbazide, on the surface appearance and deposit composition were investigated. Three electrochemical techniques, potentiodynamic polarisation (PDP), linear polarisation resistance (LPR) and electrochemical impedance spectroscopy (EIS) were used to investigate the corrosion behaviour of the alloy composition after immersion in a solution containing 1 M HCl. Energy dispersive X-ray (EDX) and scanning electron microscopy (SEM) were carried out after deposition to provide a visual aspect of the coating. The lowest corrosion current density, the highest corrosion resistance, and the highest impedance were observed in each alloy system at a scan rate of 1 mV/s. These values were: 67 μA/cm−2, 51 μA/cm−2, and 7.6 μA/cm−2 for PDP, 965 Ω · cm², 1117 Ω · cm², and 2853 Ω · cm² for LPR, and 1602 Ω · cm², 12938 Ω · cm², and 1595 Ω · cm² for EIS, corresponding to coatings without additives, coatings with the additive 4-(4-nitrophenyl)-3-thiosemicarbazide, and coatings with the additive 4-(3-methoxyphenyl)-3-thiosemicarbazide, respectively. From the SEM and EDX results it was concluded that 4-(3-methoxyphenyl)-3-thiosemicarbazide has a more pronounced effect on the coating than 4-(4-nitrophenyl)-3-thiosemicarbazide, probably due to its better adsorption on the surface of soft steel.

3

Rola palladu w elektrochemii : właściwości, procesy elektroosadzania i zastosowanie

Leniart Andrzej, Burnat Barbara, Brycht Mariola, Skrzypek Sławomira

Wiadomości Chemiczne

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2024

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[Z] 78, 7-8

987--1024

EN

Palladium is an investment metal that occurs extremely rarely, yet demand for this metal grows each year. Due to its unique properties, it plays a crucial role in many industrial sectors and everyday life. It is widely used in the automotive industry for catalytic converters, in the electronics sector for integrated circuits, in the energy sector as an electrode material in fuel cells, and for energy storage (hydrogen). Among many methods of obtaining palladium materials, electrochemistry holds great potential. By selecting appropriate parameters of electrodeposition process, it is possible to obtain palladium materials with specific chemical compositions (single-, binary-, or ternary-phase) in the form of layers or nanostructures with defined geometries (shape and size). The energy efficiency and catalytic performance of the obtained palladium materials can be enhanced by using suitable carriers with high conductivity, chemical and mechanical stability, and large surface area. Since the breakthrough announcement of cold fusion using palladium by Fleischmann and Pons, interest in palladium has increased significantly, and research on palladium-based materials continues to be extensive. The aim of this article is to discuss the properties of palladium, review research on the electrodeposition of palladium materials, and highlight selected applications (such as in fuel cells and hydrogen production and storage). Additionally, future research perspectives related to palladium will be outlined.

4

Preparation of nano SnO2-Sb2O3 composite electrode by cathodic deposition for the elimination of phenol by sonoelectrochemical oxidation

Nsaif Hind Jabbar, Majeed Najwa Saber, Salman Rasha H.

Polish Journal of Chemical Technology

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2024

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Vol. 26, nr 3

21--28

EN

The preparation of composite metal oxide to attain high efficiency in removing phenol from wastewater has a great concern. In the present study, the focus would be on adopting antimony-tin oxide coating onto graphite substrates instead of titanium; besides the effect of SbCl3 concentration on the SnO2-Sb2O3 composite would be examined. The performance of this composite electrode as the working electrode in the removal of phenol by sonoelectrochemical oxidation will be studied. The antimony-tin dioxide composite electrode was prepared by cathodic deposition with SnCl2 . 2H2O solution in a mixture of HNO3 and NaNO3, with different concentrations of SbCl3. The SnO2-Sb2O3 deposit layer’s structure and morphology were examined and the 4 g/l SbCl3 gave the more crystallized with nanoscale electrodeposition. The highest removal of phenol was 100% at a temperature of 30° C, with a current density (CD) of 25 mA/cm2 .

5

Modified Graphite with Tin Oxide as a Promising Electrode for Reduction of Organic Pollutants from Wastewater by Sonoelectrochemical Oxidation

Nsaif Hind Jabbar, Majeed Najwa Saber

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 1

307--320

EN

Most of the studies on tin oxide coatings as electrode materials were conducted on titanium; in this study, the aim was to create pure tin oxide (SnO2) films on graphite substrate, which is more prevalent than titanium. There is a lack in investigation the effect of SnCl2 and HNO3 concentrations on the prepared SnO2 electrode; therefore, the aim of this work was to study these effects precisely. Also, no previous study investigated the removal of phenol sonoelectrochemically by a SnO2 electrode, which would be accomplished in the present work. The tin dioxide electrode was produced by cathodic electrodeposition using a SnCl2·2H2O solution in the presence of HNO3 and NaNO3 on a graphite plate substrate. The impact of various operating parameters (current density – CD, HNO3 concentration, and SnCl2·2H2O concentration) on the morphology and structure of the SnO2 deposit layer was thoroughly investigated. The physical structures of the SnO2 film were determined by X‐ray diffraction (XRD), surface morphology was characterized using field-emission scanning electron microscopy (SEM), and chemical composition was analyzed using energy-dispersive X-ray spectroscopy (EDX). In a batch reactor, the sonoelectrochemical oxidation of phenol was tested to determine the performance of the best SnO2 electrodes for phenol degradation and any organic byproducts. It was discovered that 10 mA/cm2 , 50 mM of SnCL2·2H2O, and 250 mM of HNO3 were the optimum conditions to prepare SnO2 electrodes, which produced the smallest crystal size, with no appeared cracks, and gave the best phenol removal. The best prepared electrode was tested in the sonoelectrochemical oxidation of phenol with two different electrolytes and different CD, and the results showed that the phenol removal was 76.87% and 64.68% when using NaCl and Na2SO4, respectively, as well as was 63.39, 76.87, and 100% for CD at 10, 25, and 40 mA/cm2, respectively.

6

Adhesion of polymers to electrodeposited copper for a new 3D printing technology for metal-polymer hybrid components

Kiesiewicz Dawid, Oksiuta Bartosz, Pilch Maciej, Pawlik Justyna

Chemical and Process Engineering : New Frontiers

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2024

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Vol. 45, nr 4

art. no. e80

EN

3D printing has significantly evolved in recent years. Initially, only plastics were used as materials for 3D printing, but technological advancement has enabled 3D printing with materials such as metals, ceramics and biomaterials. With the development of 3D printing, there emerged a need to create a printer for producing hybrid parts, such as metal-plastic, characterized by both the exceptional strength and durability of metal and the lightweight and insulating properties of plastics. The new technique of 3D printing involves layer-by-layer metal growth in the electroplating process, as well as extrusion of a photopolymer composition, followed by UV light curing on the surface of a copper layer. Prints from this new type of 3D printer must exhibit strong adhesive bonding to prevent damage to the printed model. Therefore, mechanical tests were conducted to examine the adhesion of prepared photopolymer compositions to copper sheet coated with electroplated metal and to regular copper sheet in order to compare the obtained values. Analyzing the test results, it can be concluded that the structure of electrodeposited copper significantly improves the adhesive bond strength.

7

The influence of temperature and the magnetic field on Ni electrodeposition from citrate bath and its electrocatalytic performance towards hydrogen evolution reaction

Elsharkawy Safya, Kutyła Dawid, Boryczko Bożena, Żabiński Piotr

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 4

art. 206, 1--10

8

Preliminary studies on electrodeposition of Zn-Fe-W alloy coatings from citrate-sulphate baths

Shoaib Hafiz Muhammad, Winiarska Katarzyna, Winiarski Juliusz

Ochrona przed Korozją

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2023

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nr 2

44--47

EN

Exploratory studies of the electrodeposition process of zinc coatings containing iron and tungsten were carried out using SEM/EDS and XRD techniques. It was shown that from a citrate-sulphate plating bath composed of (mol dm−3): ZnSO4 – 0.2, FeSO4 – 0.2, Na3Cit (tri-sodium citrate salt) – 0.4, (NH4)2SO4 – 0.1 and Na2WO4 – 0.01 Zn-Fe-W alloys can be obtained on a rotating disc electrode. It was noted that the induced co-deposition of tungsten with iron only occurred at pH > 6.0. Below this value, a Zn-Fe alloy coating was obtained. In the pH range from 5.0 to 9.0, the maximum contents of tungsten (15.96 wt. %) and iron (29.36 wt. %) were shown by the coatings deposited at pH 7.0. The increase in the bath pH from 5.0 to 9.0 resulted in clear changes in the phase composition of the deposited coatings. According to the results of XRD analyzes, the following can be indicated as probable: Fe22Zn78 and Fe7W6. However, the recorded diffractograms are difficult to interpret and it was very difficult to clearly define the type of phases present in the coating without additional tests.

PL

Stosując techniki SEM/EDS i XRD, przeprowadzono rozpoznawcze badania procesu elektroosadzania powłok cynkowych zawierających żelazo i wolfram. Wykazano, że z cytrynianowo-siarczanowej kąpieli galwanicznej o składzie (mol dm−3): ZnSO4 – 0,2, FeSO4 – 0,2, Na3Cit (cytrynian tri-sodu) – 0,4, (NH4)2SO4 – 0,1 i Na2WO4 – 0,01 można otrzymać na wirującej elektrodzie dyskowej powłoki stopowe Zn-Fe-W. Zauważono, że indukowane współosadzanie wolframu z żelazem zachodziło dopiero przy pH > 6,0. Poniżej tej wartości otrzymywało się powłokę stopową Zn-Fe. W zakresie pH od 5,0 do 9,0 maksymalną zawartość wolframu (15,96% mas.) i żelaza (29,36% mas.) wykazały powłoki osadzone przy pH 7,0. Wzrost pH kąpieli od 4,5 do 9,0 powodował wyraźne zmiany w składzie fazowym osadzanych powłok. Zgodnie z wynikami analiz XRD można wskazać jako prawdopodobne występowanie: Fe22Zn78 oraz Fe7W6. Zarejestrowane dyfraktogramy są jednak trudne w interpretacji i jednoznaczne określenie rodzaju faz obecnych w powłoce bez wykonania dodatkowych badań było mocno utrudnione.

9

Effect of saccharin addition on formation, wear and corrosion resistance of electrodeposited Ni-Cr coatings

Demir Mehmet, Kanca Erdoğan, Karahan İsmail Hakki

Materials Science Poland

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2023

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Vol. 41, No. 3

111--125

EN

Numerous factors play a pivotal role in shaping the mechanical and corrosion resistance properties of electrodeposited Ni-Cr alloy coatings. This study delves into the deposition of Ni-Cr alloy coatings on AISI 1040 steel, examining the influence of saccharin additives within the electrodeposition bath. Specifically, the concentration of saccharin within the solution was varied over a range of 0 to 2 g/l. Following the electrodeposition process, a comprehensive array of characterization techniques was employed, encompassing 2D surface roughness analysis, scanning electron microscopy, X-ray diffraction, nanoindentation, energy-dispersive X-ray spectroscopy and assessments of wear and corrosion performance. The characterization results of this article reveal a compelling difference between saccharin-free Ni-Cr coatings and their saccharin-modified counterparts. Notably, microcracks, a common occurrence in saccharin-free coatings, were suppressed in the saccharin-modified Ni-Cr coatings. Additionally, the latter exhibited a smoother and more uniform surface texture. A crucial observation was that the introduction of saccharin into the bath was directly associated with an increased incorporation of chromium within the coatings, resulting in higher nanohardness values. Furthermore, the residual stress within the coatings shifted from tensile to compression as saccharin concentrations increased. Concurrently, surface roughness and wear rates exhibited a consistent downward trend with increasing saccharin concentrations in the solution. The most significant findings were seen in the domain of corrosion resistance. Saccharin-modified Ni-Cr coatings outperformed the bare steel substrate and saccharin-free Ni-Cr coatings. Intriguingly, the enhancement of corrosion resistance was not linearly proportional to saccharin concentration; the optimal corrosion resistance was achieved at a concentration of 1 g/l.

10

Synthesis of Mn-Co-Ni Composite Electrode by Anodic and Cathodic Electrodeposition for Indirect Electro-oxidation of Phenol: Optimization of the Removal by Response Surface Methodology

Ahmed Yamama A., Salman Rasha H.

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 8

107--119

EN

In the present work, Response Surface Methodology (RSM) was utilized to optimize process variables and find the best circumstances for indirect electrochemical oxidation of mimicked wastewater to remove phenol contaminants using prepared ternary composite electrode. The electrodeposition process is used for the synthesis of a ternary composite electrode of Mn, Co, and Ni oxides. The selected concentrations of metal salts of these elements were 0.05, 0.1, and 1.5 M, with constant molar ratio, current density, and electrolysis time of 1:1:1, 25 mA/cm2, and 2 h. Interestedly, the gathered Mn-Co-Ni oxides were deposited at both the anode and cathode. X-ray diffraction (XRD) and scanning electron microscopy (SEM) facilitated the qualitative characterization of surface structure and morphology of the accumulated oxides. The energy dispersive X-ray (EDX) provided a semi-quantitative analysis of deposit composition. The atomic force microscopy (AFM) apparatus quantified the roughness. We examined the efficiency of composite electrodes in coinciding with the removal of Chemical Oxygen Demand (COD) under current densities of 40, 60, and 80 mA/cm2, pH values of 3, 4, and 5, and NaCl concentrations of 1, 1.5, 2 g/l. RSM covered the optimization of process parameters in conjunction with Central Composite Design (CCD). The COD represented the response function in the optimization procedure. The optimal current density, NaCl concentration, and pH magnitude were 80 mA/cm2, 1.717 g/l, and 3, respectively. The efficiency of COD elimination of 99.925% attained after 1 hour of indirect electrochemical oxidation with an energy consumption of 152.380 kWh per kilogram of COD. The COD elimination model is significant based on the correlation coefficient (R2) and F-values, and the experimental data fitted well to a second-order polynomial model with R2 of 98.93%.

11

Substrates with different magnetic properties versus iron-nickel film electrodeposition

Białostocka Anna M., Klekotka Marcin, Klekotka Urszula, Żabiński Piotr R., Kalska-Szostko Beata

Chemistry-Didactics-Ecology-Metrology

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2023

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R. 28, NR 1-2

157--170

EN

The hereby work presents the iron-nickel alloys electroplated on the different metallic substrates (aluminium, silver, brass) using galvanostatic deposition, with and without presence of the external magnetic field (EMF). The films were obtained in the same electrochemical bath composition - mixture of iron and nickel sulphates (without presence of additives) in the molar ratio of 2 : 1 (Ni : Fe), the electric current density (50.0 mA/cm2), and the time (3600 s). The mutual alignment of the electric (E) and magnetic field (B) was changeable - parallel and perpendicular. The source of EMF was a set of two permanent magnets (magnetic field strength ranged from 80 mT to 400 mT). It was analysed the surface microstructure, composition, morphology, thickness and the mechanical properties (roughness, work of adhesion). The surface morphology and the thickness of films were observed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). The elemental composition of all FeNi films was measured using Wavelength Dispersive X-Ray Fluorescence (WDXRF). The crystalographic analysis of the deposits was carried out by X-Ray Diffraction. Depending on the used substrate, modified external magnetic field orientation influenced the tribological and physio-chemical properties of the deposited layers. The diamagnetic substrates and EMF application reduced the FeNi thickness and the average crystallites size, in contrast to the paramagnetic substrate. Parallel EMF increased the value of the tribological parameters for CuZn and Ag but decreased for Al. The content of FeNi structure was rising in the case of diamagnetic substrate and the dependence was opposite on the paramagnetic substrate.

12

Antipathogenic copper coatings: electrodeposition process and microstructure analysis

Bigos Agnieszka, Bugajska Monika, Kwiecień Izabela, Janusz-Skuza Marta, Szczerba Maciej, Ozga Piotr, Wierzbicka-Miernik Anna, Dyner Marcin, Misztela Andrzej, Dyner Aneta, Wojewoda-Budka Joanna

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 4

art. e233, s. 1--11

EN

Copper coatings are an important group of decorative-protective materials characterised by high corrosion resistance, excellent thermal and electrical conductivity, which lately gained more significance due to their antimicrobial activity. The main aim of the presented research was to electrodeposit homogenous copper coatings from the non-cyanide electrolyte solution in galvanostatic conditions on steel (1.4024) and nickel (Ni201) substrates, commercially used for surgical instruments. The effect of substrate finishes used in the production line, by shot peening with glass balls, corundum treatment and brushing on the coatings surface formation, was investigated. The substrates’ and coatings’ microstructural properties were analyzed by scanning and transmission electron microscopy, atomic force microscopy, and X-ray diffraction analysis. The current efficiency of the copper reduction on nickel and steel substrates was found to be above 95%. The copper layers adhere to both substrates, except those deposited on a brushed surface. Regardless of the substrate used, they have a nanocrystalline structure with an average crystallite size of 30 nm. Moreover, the coating surface morphology, which affects the nature of interaction with microorganisms, was effectively modified by the appropriate substrate finishing without changing the electrodeposition conditions.

13

Tribological properties of the FeNi alloys electrodeposited with and without external magnetic field assistance

Białostocka Anna Maria, Klekotka Marcin, Klekotka Urszula, Kalska-Szostko Beata

Eksploatacja i Niezawodność

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2022

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Vol. 24, no. 4

687--694

EN

The hereby work presents the tribological properties of the iron-nickel alloys and their dependence on the microstructure and thickness of the probes as well as the presence of an external magnetic field during the synthesis. Coatings were electroplated on the brass and copper metallic substrates using galvanostatic deposition in the same electrochemical bath condition (Fe and Ni sulfates) and the electric current density. The surface morphology of the films was observed by Scanning Electron Microscopy. The average composition of all FeNi coatings was measured using Energy Dispersive X-ray Spectroscopy. Tribo-mechanical properties such as microhardness, roughness, and friction coefficient were determined in the obtained structures. The morphology and tribologial properties of the FeNi coatings clearly depend on both the substrate (Cu, CuZn) itself and the presence of an external magnetic field (EMF) applied during the deposition process.

14

Characterization of nanoporous nickel-based films on electrode materials for hydrogen evolution, fabricated by dealloying technique

Bakr A., El-Aziz Ahmed M., Abdel-Karim R.

Ochrona przed Korozją

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2021

|

nr 5

134--139

EN

Nanoporous nickel-based films, with a thickness of several μm have been fabricated on Ni substrate by electrodeposition of zinc, heat treatment of modified Zn-rich layer and by selective leaching of the active zinc metal from the electrode material substrate. The fabrication process involved three steps: (i) cathodic deposition of zinc on Ni substrate, (ii) heat treatment process of the surface layer and (iii) dealloying of zinc in alkaline solution on the electrochemical route. SEM and EDS analyses were carried out after each step of the fabrication process. The dealloyed film displays a porous structure with an average pore size of the order of 0.94μm. The electrocatalytic activity of the fabricated surface towards hydrogen evolution reaction (HER) was evaluated by cathodic polarization measurements and the results have been compared to these of pure nickel and commercial porous nickel foam surface. It has been concluded that the nanoporous nickel films fabricated by electrochemical dealloying revealed considerably higher electrocatalytic activity for HER process.

PL

Nanoporowate, warstwy na baize niklu, o grubościach kilku μm wytwarzano na podłożach niklowych poprzez elektroosadzanie cynku, obróbkę cieplną zmodyfikowanych warstw wzbogaconych cynkiem i przez selektywne ługowanie cynku z wytworzonych warstw powierzchniowych. Proces wytwarzania składał się z trzech etapów: (i) katodowego osadzania cynku na podlożu niklowym, (ii) obróbki cieplnej warstwy powierzchniowej i (iii) selektywnego wytrawiania cynku w roztworze alkalicznym na drodze elektrochemicznej. Po każdym etapie procesu wytwarzania przeprowadzano analize SEM i EDS zmodyfikowanej powierzchni. Wyługowane warstwy wykazują porowatą structure z średnimi rozmiarami porów na poziomie 0.94μm. Elektroaktywność katalityczną zmodyfikowanej powierzchni w odniesieniu do reakcji wydzielania wodoru oceniano w pomiarach katodowej polaryzacji a wyniki porównano dla podłoży czystego niklu i komercyjnego, porowatego niklu gąbczastego. Stwierdzono, że nanoporowate warstwy niklowe wytwarzane poprzez selektywne ługowanie wykazywały znacząco wyższą elektroaktywność katalityczną w odniesieniu do reakcji wydzielania wodoru.

15

Optoelectronics applications of electrodeposited p- and n-type Al2Se3 thin films

Faremi A. A., Oluyamo S. S., Olubosede O., Olusola I. O., Adekoya M. A., Akindadelo A. T.

Materials Science Poland

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2021

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Vol. 39, No. 2

166--171

EN

In this paper, energy band gaps and electrical conductivity based on aluminum selenide (Al2Se3) thin films are synthesized electrochemically using cathodic deposition technique, with graphite and carbon as cathode and anode, respectively. Synthesis is done at 353 K from an aqueous solution of analytical grade selenium dioxide (SeO2), and aluminum chloride (AlCl2·7H2O). Junctions-based Al2Se3thin films from a controlled medium of pH 2.0 are deposited on fluorine-doped tin oxide (FTO) substrate using potential voltages varying from 1,000 mV to 1,400 mV and 3 minutes −15 minutes respectively. The films were characterized for optical properties and electrical conductivity using UV-vis and photoelectrochemical cells (PEC) spectroscopy. The PEC reveals a transition in the conduction of the films from p-type to n-type as the potential voltage varies. The energy band gap reduces from 3.2 eV to 2.9 eV with an increase in voltage and 3.3 eV to 2.7 eV with increase in time. These variations indicate successful fabrication of junction-based Al2Se3 thin films with noticeable transition in the conductivity type and energy band gap of the materials. Consequently, the fabricated Al2Se3can find useful applications in optoelectronic devices.

16

Zn-Cr alloy coatings: electrodeposition and properties

Osuchowska Ewa, Buczko Zofia, Olkowicz Klaudia

Journal of KONBiN

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2021

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Vol. 51, iss. 1

29--42

EN

The electrodeposition process of Zn-Cr alloy coatings under the conditions of direct and pulsed current is discussed. The Cr content in the obtained alloy coatings, the current efficiency of the process, surface morphology, structure and wettability as a function of deposition parameters, such as current density, were determined. The Zn-Cr alloy coatings of good quality contained up to 20 wt.% Cr (for direct current) and up to 9 wt.% Cr (for pulse current). All the obtained coatings had a structure typical of zinc coatings (h.c.p.) and had a hydrophobic character. The morphology of the coatings changed significantly under the influence of changes in deposition conditions.

PL

W niniejszej pracy omówiono proces elektroosadzania powłok stopowych Zn-Cr w warunkach prądu stałego i pulsacyjnego. Określono zawartość Cr w otrzymanych powłokach stopowych, wydajność prądową procesu, morfologię powierzchni, strukturę i zwilżalność w funkcji parametrów osadzania, takich jak gęstość prądu. Powłoki stopowe Zn-Cr o dobrej jakości zawierały do 20% wag. Cr (dla prądu stałego) i do 9% wag. Cr (dla prądu pulsacyjnego), Wszystkie otrzymane powłoki miały strukturę typową dla powłok cynkowych (h.c.p.) oraz wykazywały charakter hydrofobowy. Morfologia tych powłok ulegała istotnej zmianie pod wpływem zmian warunków osadzania.

17

Study on Synthesis and Modification of Conical Ni Structures by One-Step Method

Skibińska K., Semeniuk S., Kutyła D., Kołczyk-Siedlecka K., Jędraczka A., Żabiński P.

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 3

861--869

EN

In this work the conical Ni structures were obtained from an electrolyte containing NH4Cl as a crystal modifier. This process is called one-step method and allows to cover large areas with micro- and nanostructures during a single electrodeposition. Presence of NH4Cl promotes a vertical direction of structure growth in order to block a horizontal one. Additionally, this method does not require using chromic acid solution, which is dangerous for the environment. Due to the ferromagnetic properties of Ni, obtained coatings could be applied as magnetic devices. The influence of the parameters such as a preparation of copper substrate, a composition of electrolyte and electrodeposition conditions (time, the electrolyte temperature and current density) was investigated in this work.

18

Otrzymywanie powłoki galwanicznej Zn-Ni przy zredukowanej liczbie etapów przygotowania powierzchni. Część I: próby z wykorzystaniem kąpieli laboratoryjnych

Niedbała Jolanta, Wesołowski Jan

Rudy i Metale Nieżelazne Recykling

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2020

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R. 65, nr 9-10

3--11

PL

W pracy przedstawiono wyniki badania możliwości otrzymywania galwanicznej powłoki stopowej Zn-Ni przy zredukowanej liczbie etapów. Zaproponowany ekonomiczny proces pozwoli na zmniejszenie zużycia odczynników i mediów, opóźni korozję elementów linii oraz skróci czas procesu. Przy zredukowanej liczbie etapów i przy zastosowaniu gęstości prądowej równej i wyższej od stosowanej obecnie w galwanizerniach, przeprowadzono próby otrzymywania powłoki Zn-Ni z kąpieli laboratoryjnych i przemysłowych. W części I przedstawiono charakterystykę powłok otrzymanych w skróconym procesie z wykorzystaniem kąpieli laboratoryjnych. Dokonano oceny możliwości wykorzystania zaproponowanych zmian w praktyce charakteryzując właściwości powłok otrzymanych w skróconym procesie.

EN

The paper presents the results of testing the possibility of obtaining a galvanic Zn-Ni alloy coating with a reduced number of stages. The proposed economic process will reduce the consumption of reagents and media, delay the corrosion of line elements and reduce the process time. With a reduced number of stages and using current density equal to and higher than currently used in electroplating plants, tests were carried out to obtain a Zn-Ni coating from laboratory and industrial baths. Part I presents the characteristics of coatings obtained in a shortened process using laboratory baths. The possibility of using the proposed changes in practice was assessed, characterizing the properties of the coatings obtained in the short process.

19

Wytwarzanie i mikrostruktura osadzanych elektrolitycznie stopów Ni-Co i kompozytów TiO2 / Ni-Co

Ledwig Piotr, Dubiel Beata, Kopia Agnieszka

Hutnik, Wiadomości Hutnicze

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2020

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Vol. 87, nr 4

107--113

PL

Stopy Ni-Co oraz kompozyty TiO2/Ni-Co osadzono elektrolitycznie z kąpieli siarczanowo-cytrynianowych o względnej zawartości jonów Co:Ni równej 1:49, 1:24 i 1:9 stosując gęstości prądu 2,5, 5 i 7,5 A/dm2. Wpływ parametrów osadzania na morfologię powierzchni, mikrostrukturę, skład chemiczny i skład fazowy zbadano za pomocą skaningowej i transmisyjnej mikroskopii elektronowej, spektroskopii dyspersji energii charakterystycznego promieniowania rentgenowskiego oraz dyfrakcji promieniowania rentgenowskiego. Wytworzone kompozyty charakteryzowały się globularną morfologią i nanokrystaliczną mikrostrukturą. Wykazano, że w osnowie kompozytów występują pojedyncze nanocząstki oraz aglomeraty TiO2. Zawartość TiO2 w kompozytach wynosiła około 4% mas. Stwierdzono, że wielkość ziarna kompozytów TiO2/Ni-Co zależy od obecności fazy umacniającej, warunków prądowych podczas osadzania oraz stężenia Co w osnowie Ni-Co.

EN

TiO2/Ni-Co composites were electrodeposited from citrate-sulfate bath with varying Ni:Co ratios. Effect of deposition conditions on chemical composition, surface morphology, microstructure and phase composition were investigated using scanning and transmission electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. Manufactured composites were characterized by typical cauliflower surface morphology and nanocrystalline structure. Nanocrystalline TiO2 particles were embedded in the Ni-Co matrix both in the form of dispersive nanoparticles and clusters. The concentration of nc-TiO2 in composites was about 4 wt. %. Grain size of TiO2/Ni-Co composites depended on the content of strengthening phase, deposition current conditions and Co concentration in the Ni-Co matrix.

20

MHD Supported Electroreduction of Formate Nickel Complexes with Simultaneous Incorporation of TiO2 Particles

Mech K.

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 1

219--227

EN

The present work concerns analysis of the possibilities of synthesis of Ni-TiO2 composite coatings from electrolytes containing formate nickel complexes. A magnetic field was applied as an additional factor enabling modification of properties of the synthesized coatings through its influence on electrode processes. The presented data describes the effect of electrode potential, TiO2 concentration in the electrolyte as well as the value of the magnetic field induction vector on the deposition rate, composition, current efficiency, structure, surface states and morphology of synthesized coatings. The studies were preceded by thermodynamic analysis of the electrolyte. The obtained results indicated possibilities of synthesis of composites containing up to 0.97wt.% of TiO2. Depending on applied electrolysis conditions current efficiency amounted to from 61.2 to 75.1%.