Watts Bath Research Articles

Electrodeposition and Optimisation of Amorphous NixSy Catalyst for Hydrogen Evolution Reaction in Alkaline Environment.

Anion exchange membrane (AEM) water electrolysers have shown their potential in green hydrogen production. One of the crucial tasks is to discover novel cost-effective and sustainable electrocatalyst materials. In this study, a low-cost Ni-S-based catalyst for hydrogen evolution reaction was prepared via a simple electrodeposition process from a modified Watts bath recipe. Physical characterisation methods suggest this deposit film to be amorphous. Optimisation of the electrodeposition parameters of the NixSy catalyst was carried out using a rotating disk electrode setup. The optimised catalyst exhibited excellent catalytical performance in 1 M KOH on a microelectrode, with overpotentials of 41 mV, 111 mV and 202 mV at 10, 100 and 1000 mA cm-2 with Tafel slope of 67.9 mV dec-1 recorded at 333 K. Long-term testing of the catalyst demonstrated steady performance over a 24 h period on microelectrode at 100 mA cm-2 with only 71 mV and 37 mV overpotential increase at 293 K and 333 K respectively. Full cell testing with the optimised NixSy as cathode and NiFe(OH)2 as anode showed 1.88 V after 1 h electrolysis at 500 mA cm-2 in 1 M KOH under 333 K with FAA-3-30 membrane.

Deposition of a low-activity type cobalt-modified aluminide coating by slurry aluminizing of a pre-Co-electroplated Ni-based superalloy (IN738LC)

Incorporating the Co element into the β-NiAl phase as a third element enhances the hot corrosion and oxidation properties of aluminide coatings. The deposition of Co-modified aluminide coatings is limited to co-deposition by the pack cementation method or a two-step pack cementation process of Co and Al, so far. This study investigates the possibility of depositing a low-activity type of Co-modified aluminide coating by combining the electroplating process with the slurry aluminizing method. To accomplish this objective, different thicknesses of Co-electroplated layers, deposited by a Watts bath, ranging from 5 to 20 μm are slurry aluminized using a slurry consisting of Al particles as the Al source and a PVA aqueous solution as the binder at 1100 °C for 2 h. Formation mechanisms are discussed through slurry aluminizing of 5, 10, and 20 μm thick Co-electroplated layers at the temperature range of 700–1100 °C with 100 °C intervals at zero time. FE-SEM surface morphology, BSE-SEM cross-sectional observation, surface XRD characterization, and EDS elemental analysis are utilized to characterize the coatings. Results show a critical thickness of the Co layer is required to deposit a defect-free low-activity type of Co-modified aluminide coating, which is determined to be ∼10 μm in this study. The final aluminide coating thickness decreases from ∼140 to ∼65 μm by increasing the Co-electroplated layer thickness from 5 to 20 μm. The identified phases on the surface differ from β-NiAl to β-CoAl by increasing the Co-electroplated layer thickness up to critical value. The Void formation occurs by the Kirkendall effect in coatings with more Co-electroplated layer thickness than the critical value, segregating the coatings within the β-CoAl phase.

Nickel-based composites using tungsten carbides as enhancers for electroactivity for the hydrogen evolution reaction

This study explores the impact of incorporating tungsten carbides into a Watts bath on the fabrication of Ni/WC and Ni/W2C composites, comparing them with conventional Ni Watts electrodeposited electrodes. Results indicate that adding tungsten carbides to the conventional nickel bath forms rougher and more porous structures in the deposited composites. Composite electrodes exhibit significantly enhanced current density for hydrogen evolution in alkaline media compared to nickel Watts electrodes. Differential Electrochemistry Mass Spectrometry (DEMS) elucidates the hydrogen evolution mechanism, providing accurate data for Tafel plots. X-ray photoelectron spectroscopy (XPS) shows minimal impact on nickel's surface chemistry. X-ray diffractograms demonstrate that tungsten carbide particles maintain crystalline structure. X-ray dispersive spectroscopy (EDS) reveals an uneven chemical composition, with Ni/WC and Ni/W2C composites containing approximately 17% tungsten carbides. Electrochemical impedance spectroscopy (EIS) indicates higher electrochemical areas and lower charge transfer resistances in Ni/WC and Ni/W2C composites than in Ni Watts. This study contributes insights for the efficient and economical development of electrolysis systems. Notably, Ni/WC and Ni/W2C composites show promising electrochemical performance, emphasizing their potential in advancing electrolysis technology.

Nickel electroplating of 6061-T6 aluminum alloy using anodizing process as the pretreatment

Typically, aluminum and its alloys fail to be coated by the electroplating process due to the existence of an inherent oxide layer on the surface which reduces the adhesion between the coatings and the substrate. In this regard, suitable surface preparation is required before the electroplating process. In this study, the anodizing process is chosen as the surface pretreatment. For this purpose, the soft anodizing process was done in a 0.3 M oxalic acid electrolyte at 25 °C and 90 V for different duration. AAO dissolving process was performed to increase the diameter of the pores. Finally, electroplating of nickel was performed in a Watts bath at 40 °C, pH of 3, and different current densities. Three variable of anodizing and dissolving durations and electroplating current density were optimized by a response surface methodology to form a continuous layer of electroplated nickel on the surface. FE-SEM surface morphology, SEM cross-sectional observations, surface XRD characteristics and Daimler-Benz adhesion test were performed to characterize and evaluate the coatings. The optimization of the three variables led to a sequence process of a 9 min anodizing treatment, followed by a 100 min dissolving stage, then electroplating under a current density of 20 mA/cm2. The formation mechanism of the electroplated layer is thoroughly discussed.

Substrate thermal expansion coefficient effect on cracks induced by the high-heat treatment of electroplated Ni-P films for power devices

Automotive power semiconductors are required not to fail at high-temperature mounting (∼400 °C), and a structural design that prevents defects as well as cracks is essential. In this study, we focused on the thermal expansion coefficient of medium-phosphorus Ni films (P content: 8–9 wt%), which are commonly used for soldering or wire-bonding, with the substrates on which they are electroplated to investigate the effects of high-temperature heating on cracks induced in the Ni films. The Ni-P films were deposited on Al, Cu, Ni, and Fe substrates via electroplating technique using a Watts bath containing phosphorous acid. By heating to approximately 360 °C, the Ni-P film shrank because of the phase transition to a phosphorus compound mainly composed of Ni3P. As a result of the Ni film indentation test after heating to 400 °C, cracks were induced in the Ni film on the Cu substrate but not on the Ni substrate. The thermal expansion coefficients of the Cu and Ni substrates at approximately 360 °C were 17.4 and 14.8 µm m−1 °C−1, respectively; suggesting that the residual stress at the interface between the Ni film and the substrate affects cracking.

Improving the properties of nickel/graphene oxide coated copper plate by changing the electroplating process conditions

One of the attractive ways to improve the mechanical properties and prevent damage to the surface of the copper plate is to create a nickel/graphene coating on it. In this work, the effect of bath type and process conditions on mechanical and wettability properties of nickel/graphene oxide coated copper plate via electroplating, has been investigated. Ultrasonic stirring of the bath with a power of 200 W increased the hardness of the coating to 747 Vickers and the wetting angle with molten steel to 125° by uniformly distributing the graphene oxide layers among the nickel grains and preventing the growth of the grains. By using a chloride bath instead of a Watts bath, due to the adhesion and delamination mechanism, a slight weight loss occurred in the pin-on-disk wear test. The coating obtained by electroplating in a chloride bath containing 20 cc of colloidal graphene oxide had a structure with a thickness of 12–15 μm consisting of large and compact masses of cauliflower with a uniform distribution of graphene layers. This sample shown a contact angle of 130° with the surface tension of 25 × 10−6 N/m to the aluminum melt drop and a 135° and 120 × 10−6 N/m to the steel melt drop.

Corrosion resistance, thermal diffusivity and mechanical properties of Ni–SiO2 nanocomposite coatings on a 316 stainless steel for heat exchanger applications

Abstract In this study, the effect of pure Ni and Ni–SiO2 nanocomposites coatings on corrosion, wear resistance and thermal conductivity of 316 stainless steel substrates was investigated with the purpose of extending the service life of 316 stainless steel plate heat exchangers. The nanocomposite coatings were developed by electroplating process in a Watts bath in different concentration values of SiO2 nanoparticles (10, 20 and 30 g l−1). Electrochemical corrosion was run to examine the corrosive performance of the coatings. The results showed that the Ni–SiO2 nanocomposite with concentration of 30 g l−1 had a higher corrosion resistance. A pin on disk wear test demonstrated that, in comparison to 316 stainless steel, the wear resistance of the Ni–SiO2 nanocomposite (30 g l−1) was up to 25% lower while its friction coefficient was almost the same. In addition, as measured via the laser flash method and differential scanning calorimetry, the thermal diffusivity and specific heat capacity of the sample respectively were found to be 32 and 43% lower in comparison to 316 stainless steel. Microhardness measurement via a Vickers microindenter showed that the microhardness of the Ni–SiO2 nanocomposite coating was more than three times higher than that of 316 stainless steel for all the reinforcement concentrations.

Probing into the properties of B4C reinforced nickel phosphorus-based nanocomposite coating

Nickel-based coatings are well known for their good corrosion resistance performance. However, these materials suffer from inferior mechanical properties that limit their wider application. This work investigates the synthesis, and performs an exhaustive characterization, of Ni–P–B4C nanocomposite coatings developed through conventional electrodeposition using a modified Watts bath. The study examines the effect of an increase in the concentration of boron carbide nanoparticles (BCNPs) on the structural, morphological, topographical, mechanical and electrochemical properties of the nanocomposite coating. Vickers microhardness tester and nanoindentation technique were utilized to elucidate the role of BCNPs in modifying the mechanical response of nanocomposite coatings. Furthermore, corrosion resistance of the nanocomposite coatings was investigated through d.c potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Comparison of the properties of the developed coatings revealed the remarkable improvement in the properties of Ni–P–B4C nanocomposite coatings when compared to the bare mild steel substrate and the Ni–P coatings. The enhanced corrosion resistance and superior mechanical properties of Ni–P–B4C nanocomposite coatings make them attractive for many industries. Based upon the experimental findings, a possible mechanism for the synthesis and improved corrosion resistance of Ni–P–B4C nanocomposite coatings was also proposed.

Improving the Characteristics of Nickel Coatings Produced on Copper from Watts Bath in the Presence of Ascorbic Acid – Combined Experimental and Theoretical Study

Improving the Characteristics of Nickel Coatings Produced on Copper from Watts Bath in the Presence of Ascorbic Acid – Combined Experimental and Theoretical Study

Effect of sodium dodecyl sulfate and different SiC quantities on electrodeposited Ni-Co alloy coatings

Ni-Co nanocomposites Prepared by electrodeposition in a modified Watts bath containing various quantities of silicon carbide SiC and the organic additive sodium dodecyl sulfate SDS as a surfactant. The influence of nanoparticle incorporation on the electrodeposit microstructure, mechanical characteristics, and deformation process was studied. Vickers micro-hardness and weight loss tests were used to study the mechanical properties and morphology. The microstructure has also been analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Co-deposition of uniformly dispersed SiC particles, on the other hand, was found to improve the extreme tensile strength of the deposits significantly; SDS lowered the surface tension, allowing the SiC particles to fill in all remaining gaps to achieve a homogeneous surface. A process involving atoms that can dramatically improve flexibility. The incorporation of SiC particles and raising the strain rate encouraged a ductile fracture mode in a nano-crystalline Ni-Co matrix, which demonstrated a mixed mod behavior of flexible and brittle fracture; it was evident that the addition of SDS increases the concentration of SiC particles in general on Ni-Co samples. Moreover, compare Ni-Co with various amounts of SiC and Ni-Co/SiC with adding SDS. Furthermore, to achieve the highest possible electroplating efficiency.

Synergistic effect of L-cysteine and iodide ions during electrodeposition of nanocrystalline nickel from a Watts bath

ABSTRACT Nickel deposited from the Watts bath with L-cysteine (L-Cys) as a new organic brightener additive, and/or iodide ion was accomplished on a copper cathode. Cathodic polarisation, anodic linear stripping voltammetry, i-t transients, throwing power and cathodic current efficiency were investigated thoroughly. The surface of the produced Ni coatings was analysed using scanning electron microscope and X-ray diffraction (XRD) methods. The results showed that the inhibition of nickel reduction was observed in the presence of L-Cys or in the presence of iodide ions individually. Excellent inhibition was achieved with the addition of a mixture of L-Cys and I− ions due to their co-adsorption on the cathode surface (in a synergistic effect). Moreover, the TP value of the Watts bath in the presence of a mixture of L-Cys and I− ions is four times its value in the absence of this mixture. XRD measurements showed that the (200) level was the most preferred direction for growth and the intensity of all peaks increased considerably with a combination of L-Cys and I− ions. Fine-grained and pit-free deposits that were firmly adherent to the substrate were produced using a combination of L-Cys and NaI.

Investigating the Properties of Electrodeposited of Ni-P-ZrC Nanocomposite Coatings.

Superior corrosion resistance along with higher mechanical performance is becoming a primary requirement to decrease operational costs in the industries. Nickel-based phosphorus coatings have been reported to show better corrosion resistance properties but suffer from a lack of mechanical strength. Zirconium carbide nanoparticles (ZCNPs) are known for promising hardness and unreactive behavior among variously reported reinforcements. The present study focuses on the synthesis and characterization of novel Ni-P-ZrC nanocomposite coatings developed through the electrodeposition technique. Successful coelectrodeposition of ZCNPs without any observable defects was carried out utilizing a modified Watts bath and optimized conditions. For a clear comparison, structural, surface, mechanical, and electrochemical behaviors of Ni-P and Ni-P-ZrC nanocomposite coatings containing 0.75 g/L ZCNPs were thoroughly investigated. The addition of ZCNPs has a considerable impact on the properties of Ni-P coatings. Enhancement in the mechanical properties (microhardness, nanoindentation, wear, and erosion) is observed due to reinforcement of ZCNPs in the Ni-P matrix, which can be attributed to mainly the dispersion hardening effect. Furthermore, corrosion protection efficiency (PE%) of the Ni-P matrix was enhanced by the incorporation of ZCNPs from 71 to 85.4%. The Ni-P-ZrC nanocomposite coatings provide an exciting option for their utilization in the automotive, electronics, aerospace, oil, and gas industry.

Development of dispersion layers for dental drills with reduced nickel release

ObjectivesWithout rotating instruments, for example diamond-coated drills with a core made of stainless steel, the dental routine would be unimaginable, since these are used in almost every dental activity and are thus indispensable for the professional practice. Unfortunately, such drills release Nickel particles to a high content into the cooling water of the drill. Values up to 1.3 mg/l Nickel were found by ICP – OES in the cooling water of the drillers which is of course also transferred into the patient's oral cavity with possible severe negative effects. Therefore, novel plating procedures have to be developed to increase the patients (and dentists) safety during treatment. MethodsDispersion layers with the hard metal Tungsten carbide (WC) particles on stainless steel blanks were deposited following two synthesis routines (i) Plasma-Electrolytic Oxidation (PEO) and (ii) galvanic plating out of a Watts bath. Both were accomplished using water-based electrolytes. ResultsIn order to verify the dental applicability of the developed coatings, tests-drills were accomplished under defined conditions on plastic teeth for the sake of reproducibility.Commercially produced drills were compared with the newly plated ones by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and the drilling cooling water was examined for heavy metal residues using Inductively Coupled Plasma (ICP) analytics. The resulting grinding patterns in the plastic teeth were investigated by light microscopy and SEM.It could be shown that dispersion layers plated by a galvanic procedure showed a reduced Nickel release compared to a commercial driller by factor 7.6 and 13.4 compared to PEO plated ones during dental treatments. ConclusionsFollowing the clinical significance the Watts bath plated drillers showed a better WC particle distribution on the surface and better abrasive properties during the drilling experiments compared to PEO plated drillers. In addition the Nickel release during dental use is much less from the galvanic treated ones. By optimising the plating condition from the Watts dispersion bath further novel drilling devices with significantly reduced release of Nickel particles can be developed for the benefit of the patients.

Fabrication of Robust Superhydrophobic Nickel Films on Steel Surface With High Corrosion Resistance, Mechanical and Chemical Stability

Abstract Superhydrophobic films were successfully grafted on a steel substrate using potentiostatic electrodeposition of nickel followed by treatment with myristic acid (MA) as a low surface energy material. A scanning electron microscope (SEM) was used to investigate the surface topography of the prepared superhydrophobic films. The results revealed that the prepared Ni films modified by myristic acid have micro-nano structures. Fourier transform infrared spectrophotometer (FTIR) and X-ray diffraction (XRD) measurements showed that the steel substrate was coated with nickel film modified with myristic acid. Three different nickel films were prepared: the Ni-MA (I) deposited from pure nickel sulfate bath (1.0 M NiSO4), Ni-MA (II) deposited from pure nickel chloride bath (1.0 M NiCl2. 6H2O), and the third Ni-MA (III) film deposited from Watts bath (0.2 M NiCl2. 6H2O and 0.8M NiSO4). The superhydrophobic Ni-MA (I) film has the highest corrosion resistance, chemical stability, and mechanical abrasion resistance, while Ni-MA (II) film has the lowest properties.

Optimization of Ni-Co-metallic-glass powder (Ni60Cr10Ta10P16B4) (MGP) nanocomposite coatings for direct methanol fuel cell (DMFC) applications

In this research, a novel Ni-Co-metallic glass composite was fabricated and the effect of the co-deposition of Ni60Cr10Ta10P16B4 amorphous metallic glass powder (MGP) on the morphology and electrocatalytic properties of Ni–Co coatings was evaluated. The process was initiated by producing Ni60Cr10Ta10P16B4 via mechanical alloying of elemental powders using a planetary ball mill. Then, Ni–Co nanocomposite coatings were deposited on a copper substrate by the addition of different amounts of MGP via the electrodeposition method in a Watts bath. Then, the microstructure and chemical composition of the deposits were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) successively. The electrocatalytic performance of the coatings was evaluated in a methanol-containing alkaline (1 M NaOH) solution through cyclic voltammetry (CV). The enhancement of the electrocatalytic activity of Ni–Co coating through the co-deposition of MGP was observed. It was also concluded that the electrocatalytic properties of composite coatings are optimized when 7.5 g L−1 of MGP is added to the electroplating bath. Moreover, MGP was demonstrated to have altered the microstructure and the content of Co besides enhancing the roughness and specific surface of coatings.

Addition of Nickel by the Watts Bath as a Way to Correct the Phase Balance on Nd:YAG Pulsed-Laser-Welded UNS S32750

Addition of Nickel by the Watts Bath as a Way to Correct the Phase Balance on Nd:YAG Pulsed-Laser-Welded UNS S32750

Effect of current density on the microstructure and morphology of the electrodeposited nickel coatings.

The aim of this research work was to study the effect of deposition current density on microstructure and surface morphology of electrodeposited nickel coatings. For this purpose, nickel deposits have been synthesized by direct current from Watts bath without additive, to limit the incorporation of pollutants resulting from surface adsorption or electro-activity of these compounds. Nickel deposits have been investigated by scanning electron microscopy and X-ray diffraction. Cyclic voltammetry was also used to gain information on the general behavior of the deposition. The optimum conditions of deposition were established and the influence of current density on the grain size, surface morphology, and crystal orientation was determined.

Iridium oxide-nickel-coated titanium anodes for the oxygen evolution reaction

IrO2-Ni-modified Ti electrodes have been prepared by a Ni-mediated galvanic replacement method. A smooth Ni film has been electrodeposited on the Ti substrate from a Watts bath and its surface layers spontaneously exchanged with metallic Ir upon treatment with an Ir(IV) solution. Anodization of the resulting Ir(Ni)/Ti electrodes by means of continuous potential cycling in acid solutions resulted in the formation of porous IrO2 coatings showing typical Ir oxide/hydroxide surface electrochemistry. SEM pictures revealed that the thus prepared IrO2/Ir(Ni)/Ti electrodes consisted of continuous films with a nodular morphology (as confirmed by AFM). The composition of the coatings was estimated by EDS and XPS spectroscopy while the Ir mass loading was determined by ICP-MS following etching in acid. These electrodes have been tested as oxygen evolution reaction (OER) anodes by slow potential sweep voltammetry and were proven comparable or better than state-of-the-art thin thermal film and nanoparticulate IrNiOx-based electrodes (exhibiting ca 2 A mgIr−1 at η=300 mV). The recently established enhancement of IrO2 OER activity by Ni, combined with the widespread use of Ti as a stable electrode substrate, make IrO2/Ir(Ni)/Ti attractive candidates for Dimensionally Stable Electrodes (DSAs).

Combined Effect of Sodium Lauryl Sulphate and Saccharin on Microstructure and Corrosion Performance of Electrodeposited Nickel Prepared from Modified Watts Bath

Combined Effect of Sodium Lauryl Sulphate and Saccharin on Microstructure and Corrosion Performance of Electrodeposited Nickel Prepared from Modified Watts Bath

Electrochemical and thermomechanical behavior of nickel–graphene oxide (2-4L GO) nanocomposite coatings

In this research work, nanocomposite coatings of nickel reinforced with graphene oxide (GOs) were produced by electrodeposition on steel substrate discs from the modified Watts bath. The resultant coatings were evaluated in terms of their surface morphology by atomic force microscopy and thermomechanical and electrochemical corrosion characteristics. The electrodeposited coatings showed variation in the electrochemical and thermomechanical behavior as the function of GO content where they show the optimum characteristics for 0.1 wt.% GO. The relatively lower concentrations of GO produced composites with greater surface homogeneity and lower roughness, whereas when the GO content is increased, the coatings show increased surface roughness. Electrochemical corrosion resistance of nickel is increased by incorporation of GO up to 0.1 wt.% due to decreased grain boundary area in the coatings and the uniform dispersion of the nanophase ensured by prior probe sonication and magnetic stirring during the co-deposition. The nickel composite coatings with 0.1 wt.% GO also showed improved thermomechanical behavior with higher recovery at 473 K.