Electroless Method Research Articles

Improving the tribological and corrosion behavior of Ni[sbnd]B coating with low boron content from optimized lead-free bath on aluminum alloys

This study focuses on producing environmentally friendly, lead-free nickel‑boron (NiB) coatings as an alternative to hard chromium coatings. Using the electroless method, the NiB coatings were fabricated from a lead-free bath, and the effects of varying B and Ni concentrations on the coatings' chemical composition, surface morphology, hardness, corrosion resistance, and wear performance were investigated. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to analyze surface morphology and phase composition. Corrosion performance was evaluated using potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS), while wear behavior was tested at sliding speeds of 20, 30, and 40 cm/s. The study highlights the critical role of sliding speed on wear mechanisms, friction coefficient, wear rate, and surface morphology. The analyses revealed that the optimal NiB coating, containing 34 g/L Ni and 3 g/L B, exhibited the highest hardness, the lowest corrosion rate, and the highest wear rate performance. The values obtained from these analyses were 891 HV for hardness, 8.87 × 10−6 mpy for corrosion rate, and 2.21 × 10−4 mm3/N·m for wear rate. The use of analysis of variance (ANOVA) identified key factors influencing these properties. The findings suggest that optimizing boron and nickel concentrations significantly enhances NiB coatings' corrosion resistance and wear performance, making them suitable for industrial applications.

A review of recent advances and applications of inorganic coating for oil and gas pipe systems

The oil and gas pipe systems are a crucial part of the infrastructure. The structural integrity of pipes is diminishing as a result of environmental damage. In recent years, the oil and gas industry has witnessed significant advancements in the development and application of inorganic coatings for pipeline systems. These coatings are essential for enhancing the durability, safety, and efficiency of pipelines by providing superior resistance to corrosion, abrasion, and chemical attacks. This review paper delves into the latest fabrication strategies for API pipe coatings, with a focus on the electroless method, electrodeposition method, thermal spray method, thermochemical method, and other emerging techniques. Each method is evaluated in terms of its principles, advantages, limitations, and suitability for different operational environments. Among the coating methods, the electroless process is one of the most popular methods. The paper also highlights innovative approaches and materials that have the potential to revolutionize the field. By providing a comprehensive overview of current technologies and their applications, this review aims to guide future research and development efforts, promoting the adoption of advanced inorganic coatings in the oil and gas industry to ensure the longevity and integrity of critical infrastructure.

Effect of the insertion of silver nanoparticles on the performance and electrical features of Ag/SiNWs Schottky diode

In this paper, we studied the effect of the passivation of silicon nanowires (SiNWs) by silver nanoparticles (AgNPs) on the efficiency of Ag/SiNWs/Si Schottky diodes. SiNWs are obtained by one-step Ag-assisted chemical etching method. AgNPs were deposited on SiNWs using an electroless dipping method. Schottky junction devices have been successfully made using silicon nanowires coated with silver nanoparticles. The current–voltage (I-V) characteristics of Ag/AgNPs-SiNWs Schottky diode have been investigated by varying the immersion time in silver nitrate solution from 1 to 5 min. The I-V characteristics presented in logarithmic scale confirmed the domination of SCLC conduction mechanism at high voltage. The ideality factor (n), height of potential barrier (φb) and series resistance (Rs) of diodes are calculated by adopting the Cheung method. Compared to the Ag/SiNWs Schottky junction, the diode that presents AgNPs at the interface shows a significant improvement in electrical parameters. The potential barrier reaches 1.09 eV and the ideality factor is reduced to 2.64 with the presence of AgNPs for an immersion time of 1 min. Norde’s equation has also been used to calculate the series resistance and the potential barrier. The results obtained by Norde method are slightly shifted compared to those found by Cheung functions while the findings concerning the optimization of the immersion time are practically the same.

Properties of Ni-B/B Composite Coatings Produced by the Electroless Method under Semi-Technical Line Conditions

Composite coatings have been successfully fabricated at the laboratory scale in many research centers around the world; however, it is still a major challenge to transfer the positive results of the work to the industrial scale. This paper presents the technology for the production of Ni-B and Ni-B/B composite coatings on a pilot experimental semi-technical line by chemical reduction. A process scheme for the fabrication of Ni-B layers and composite coatings with a nickel–boron matrix and a dispersive phase in the form of boron nanoparticles was developed. All stages of the fabrication process were described in detail. The dispersion phase of the boron particles was characterized, and the performance properties of the Ni-B and Ni-B/B composite coatings produced on a pilot electroplating line were studied. The structure and morphology of the Ni-B/B composite coatings were characterized for comparison with nickel–boron coatings. Their mechanical and tribological properties and adhesion to the substrate were studied. The influence of the dispersion phase of boron particles on the structure and functional properties of the composite coatings was evaluated. In order to improve the performance of the fabricated coatings, a heating process at 400 °C was carried out, and the performance of Ni-B and composite Ni-B/B coatings was studied after the heat treatment operation.

Palladium effect on electrochemical hydrogen storage properties of nanoporous silicon

Coating porous silicon with metal catalysts such as palladium is considered a reliable method to improve the hydrogen storage performance of electrodes. Here, in order to evaluate the most effective use of Pd nanoparticle or Pd thin film, Pd nanoparticles with a size of 36 nm obtained by electroless method, and a Pd thin film with a thickness of 30 nm deposited by thermal evaporation were coated onto nanoporous silicon sample” and studied. The Pd deposits were confirmed by Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The obtained electrode materials: PS and Pd/PS were characterized by different electrochemical characterization techniques: cyclic voltammetry (CV) and galvanostatic charge/discharge. The results showed that Pd NPs/PS achieved the highest hydrogen storage capacity with a value of 425.9 mA h g-1. These results confirm that using Pd nanoparticles as catalyst metal is more suitable to improving the hydrogen storage capacity of electrode materials.

Enhancing the performance of surface-textured Ge Schottky photodetectors using the electroless chemical etching method

Enhancing the performance of surface-textured Ge Schottky photodetectors using the electroless chemical etching method

Synthesis of biphenyl via sustainable Suzuki-Miyaura coupling reaction using mesoporous MCF-supported tin-palladium nanoparticles

The current work presents a novel approach to synthesizing monometallic palladium (Pd) and bimetallic tin-palladium (Sn-Pd) nanoparticles anchored to mesostructured cellular foam silica (MCF). The monometallic catalyst Pd@MCF was prepared by the impregnation method, whereas the bimetallic catalyst Pd@MCF(Sn) was prepared by a green electroless reduction method. Our findings demonstrate that the bimetallic Sn-Pd nanoparticles produced through green electroless reduction exhibit no aggregation or clustering, and possess high and uniform dispersion, smaller average particle size and a narrower distribution of particle size than Pd nanoparticles obtained via impregnation. The synthesis of Pd@MCF(Sn) used tin as one of the metallic components of the catalyst and also as a reducing agent rather than conventionally used harmful reducing agents in the electroless reduction method. Remarkably, the introduction of tin into the catalyst system also displays a synergistic effect in the Suzuki-Miyaura coupling (SMC) reaction. The monometallic Pd@MCF catalyst was outperformed by the bimetallic Pd@MCF(Sn) catalyst in terms of catalytic activity for SMC reaction of phenylboronic acid with iodobenzene to produce biphenyl without using toxic reagents, organic solvents, costly phosphine ligands or protective atmospheres. This study also explored and optimized the factors controlling the reaction rate, offering insightful information to improve the production of biphenyl. The reaction follows a second-order kinetics with an apparent activation energy of 8.2 Kcal/mol by applying the Langmuir-Hinshelwood-Hougen-Watson (LHHW) mechanism. Here, we present a promising strategy for formulating a highly effective and eco-friendly catalyst for sustainable production of biphenyl using Suzuki-Miyaura coupling reaction.

Investigation of Ni-Cu-B and Ni-Cu-Sn-B coatings developed by electroless method

Due to their remarkable mechanical properties and tribological behaviour which is equivalent the hard chrome coating, electroless Nickel–Boron coatings have been employed in a variety of industries. With the advent of emerging and challenging applications, there has been a need to develop newer variants of the novel Ni-B binary variant. The present work therefore investigates Ni-B-Cu coatings in a quest to achieve higher wear and corrosion resistance. A stabilizer free bath and tin chloride stabilized bath was formulated for the same to remove the harmful lead nitrate from the coating formulation. The concentration of copper sulphate was varied from 0.3 to 0.7 g/L in both the bath formulations. Based on the mass gain of the specimens, coatings obtained from 0.6 g/L copper sulphate was further investigated. The surface morphology of as-plated samples was observed which shows nodular structure and the growth was different compared to lead stabilized baths. The constant load and progressive scratch test were done to evaluate scratch hardness and coating failure respectively.

Development of a Simple Electroless Method for Depositing Metallic Pt-Pd Nanoparticles over Wire Gauge Support for Removal of Hydrogen in a Nuclear Reactor.

Electroless noble metal deposition on the conducting substrate is widely used to obtain the desired film or coating on the substrate of interest. Wire-gauge-based Pt/Pd/Pt-Pd (individually, sequentially, and simultaneously deposited) catalysts have been developed using formaldehyde and sodium formate as reducing agents. Various surface pretreatment methods like SnCl2 + PdCl2 seeding, oxalic acid etching, and HCl activation (etching) have been employed to obtain the desired noble metal coating. Minimum time duration was observed for simultaneously deposited catalysts using formaldehyde as a reducing agent. Prepared catalysts were characterized for noble metal deposition, coating kinetics, surface morphology, and binding energy. The catalyst was found to be active for H2 and O2 recombination reactions for hydrogen mitigation applications in nuclear reactors.

Silver-based conductive coatings as lightning strike protection for composite aircraft

Lightning strike protection of composite structures is an increasingly studied subject in the aerospace industry due to the need for finding novel protection solutions for low conductive composites. This work presents two silver-based lightning protective conductive coatings for potential replacement of expanded copper foil (ECF) as lightning strike protection (LSP). The first solution consists of an electroless method to produce silver-coated carbon fibres (SCCF). The SCCF are integrated as a sacrificial ply on a carbon fibre reinforced polymer (CFRP) panel with four different areal densities, using an epoxy-based primer or a PEDOT:PSS conductive ink as binder. The second solution is a silver-based commercial product consisting of a two-part epoxy with silver flakes, which acts as a sprayable thin coating beneath the paint layer.The protected CFRP panels were covered with aerospace-grade paint for realistic finishing and were subjected to high impulse current strikes. All four conductive coatings containing SCCF exhibited around 45%–50% retention of flexural strength, although largely inferior to painted expanded copper foil's resistance to emulated lightning strikes. The silver-based commercial product showed 83% retention of flexural strength and 97% retention of effective bending modulus, with a comparable performance to the painted expanded copper foil. The resulting retention of flexural strength, the absence of severe damage to the structure, its versatility for complex geometries and the easy manufacturability of the silver-based commercial coating makes this approach a good candidate for the replacement of ECF as a solution for LSP.

P11 Lubricant-infused silver-polytetrafluoroethylene coated urinary catheters inhibit adhesion of host-secreted proteins and biofilm formation

Abstract Objectives The adhesion of specific host-derived proteins (particularly fibrinogen) and subsequent biofilm formation play a central role in the pathogenesis of catheter-associated urinary catheter infections (CAUTIs). However, very few catheter materials have proven to be able to simultaneously prevent both bacterial and protein adhesion in a complex physiological environment (i.e. urine). The aims and objectives of this research were to (i) develop silver-polytetrafluoroethylene (AgF)-based coatings with a wide range of surface energies; (ii) test their antifouling performance; and (iii) investigate the influence of surface energy on biofouling accumulation. Methods Standard AgF coatings with tailored surface energies (ranging from 18 mJ/m2 to 42 mJ/m2) were fabricated using an electroless method. By spontaneous polycondensation 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTES) onto the AgF sublayer, a lubricant-infused AgF coating (AgFP) was obtained. The surface morphology, chemical composition, and roughness were characterized by SEM, EDS and AFM, respectively. The surface energy was characterized using a contact angle approach and calculated using the Van Oss method. The anti-adhesion performance of the coated catheters against proteins (fibrinogen [Fgn]; BSA) and bacteria (Escherichia coli; Proteus mirabilis) was examined and compared with commercial all-silicone catheters. Results The results showed that there exist two separate optimum surface energies where bacterial (∼25 mJ/m2) and protein adhesion (∼35 mJ/m2) are minimal (Figure 1). The deposition of fibrinogen on surfaces significantly accelerated bacterial attachment and biofilm formation, whereas the AgFP coating with the smoothest surface and ultralow surface energy (∼12 mJ/m2) displayed significant antibiofilm and anti-protein activities compared with uncoated silicone surface traditional AgF coatings (Figure 2). Figure 1.Surface energy on adhesion of bacteria and proteins. Figure 2.Biofilm formation on Si, AgF and AgFP surfaces after 1 day co-culture in pure bacterial suspension and protein-supplemented bacterial suspension. Scale bars correspond to 40 μm. Conclusions The inclusion of lubricant into the AgF matrix leads to the formation of a smooth and super-repelling catheter surface, leading to ultralow adhesion for both bacteria and proteins. Surprisingly, our results indicated that there exists an optimum surface energy where the adhesion of both bacteria and proteins is minimal, which further extended the classic ‘Baier curve’.

Investigation of corrosive and mechanical behaviour of Ni-P doped coating by utilizing electroless method

Corrosion is a major concern for steel structures, requiring significant investments for corrosion resistance. This study focused on applying Ni-P and Ni-P with surfactant electroless coatings to TMT steel rebar. The deposition rate of the electroless bath was investigated at different stirrer rotation speeds, with 300 rpm identified as optimal. Morphological and structural analyses were conducted using FESEM and XRD techniques. The average coating thickness reached 131.47 µm at 300 rpm. The addition of admixtures like lactic acid, succinic acid, and citric acid improved coating efficiency. The corrosion behavior of TMT rebar with Ni-P coating and Ni-P with surfactants was examined using EIS and polarization methods. Corrosion current densities were measured as 3.82µA cm-2, 3.91µA cm-2, and 4.1µA cm-2 for TMT steel, Ni-P coated, and Ni-P with surfactant-coated rebars, respectively.

Effect of boron carbide reinforcement on surface properties of electroless Ni–B and Ni–B–W coatings

Today, composite coating of nickel-boron with an electroless method is considered as an innovative, attractive, and trend topic. It is known that the hardness and tribological properties of electroless nickel-boron (EN-B) coating can be improved with co-deposition of ceramic particles. In this study, boron carbide (B4C) was added to binary (Ni–B) and ternary (Ni–B–W) EN-B coatings: (i) Ni–B–B4C, and (ii) Ni–B–W–B4C. Surface morphology, phase structure, tribological characteristics, and electrochemical behaviors for all coatings were investigated and compared. The surface morphology of composite coatings was transformed from cauliflower to cloudy-shaped with the addition of B4C particles. Characteristic amorphous structure with some degree of crystallinity was obtained at all types of coatings. Experimental test results revealed that the boron carbide particles provide a noticeable enhancement in hardness. The hardnesses of composite coatings were improved by approximately 52% in Ni–B–B4C and 62% in Ni–B–W–B4C compared to EN-B coatings. Boron carbide reinforcement and poly-alloying with tungsten caused an increase of hardness at Ni–B from 673 HV0.025 up to around 1096 HV0.025 (Ni–B–W–B4C) which is a noticeable increase in hardness. With boron carbide addition binary and ternary coatings wear factors showed a discernible diminishment by several times. Besides, electrochemical analyses indicated a minimal decrease in the corrosion resistance of composite coatings compared to that of Ni–B and Ni–B–W coatings.

Heterogeneous Photocatalysis using Electroless Deposition of Ni/NiO Nanoparticles on Silicon Nanowires for the Degradation of Methyl Orange

Aims: This work uses the MACE method to synthesize SiNWs- NiNPs/NiONPs to degrade organic pollutants by photocatalysis. Background: Photocatalytic degradation has been applied as an attractive solution to remove several organic pollutants. Heterostructured nanomaterials have become an interesting platform for investigation. Metal-assisted chemical etching (MACE) stands out as a promising technique because it is simple, low cost, and fast. Objective: Attain the degradation of methyl orange (MO) in the presence of silicon nanowires (SiNWs) in heterojunction with Nickel/Nickel Oxide nanoparticles (NiNPs-NiONPs). Methods: SiNWs were synthesized by metal (Ag) assisted chemical etching (MACE) of monocrystalline silicon wafers. NiNPs were non-electrolytically deposited on the SiNWs (electroless method). The morphology of the SiNWs- NiNPs/NiONPs was observed by SEM. Results: Heterogeneous photocatalytic degradation of methyl orange (C14H14N3NaO3S) in an aqueous solution at a concentration of 20 ppm had an efficiency of 66.5% after 180 min under UV irradiation. The MO degradation percentage was determined using UV-visible spectrophotometry. Conclusion: The SiNWs-NiNPs/NiONPs were obtained composed mainly of Si covered by SiO2 decorated on the tips with Ni (II) in the form of NiO and a small amount of nickel metal. The removal efficiency obtained at 180 min of light exposure was 66.5%. After the photocatalysis tests, further oxidation of the NiNPS into NiONPS, was attributed to the reactive oxygen species in the aqueous medium based on the changes of the oxygen and Ni2p3/2 peaks by XPS. Other: Through XPS, the oxidation state of the SiNWs- NiNPs/NiONPs was analyzed.

Electroless deposition of Ni-W-Mo-Co-P films as a binder-free, efficient and durable electrode for electrochemical hydrogen evolution

In this study, the manufacture of Ni-W-Mo-Co-P, Ni-Mo-Co-P, Ni-W-Co-P, Ni-W-Mo -P, Ni-Co-P, Ni-Mo-P, Ni-W-P, and Ni-P alloying coatings through electroless method on the copper substrate was investigated. The elemental and structural tests showed that the alteration of the Ni-P electroless basic bath composition by introducing sodium tungstate, sodium molybdate, and cobalt chloride additives enabled the deposition of alloying coatings. Linear Sweep Voltametry (LSV) tests revealed that the Ni-W-Mo-Co-P sample (NWMCP) coated in an alkaline bath with 18 g/l Nickel (II) sulfate, 12 g/l Ammonium acetate, 12 g/l Sodium citrate, 12 ml Lactic acid, 12 g/l Sodium hypophosphite, 8 g/l Sodium tungstate, 0.2 g/l Sodium molybdate, and 10 g/l Cobalt (II) chloride was featured with the best electrocatalytic properties with η10 = −41, η20 = −46, η100 = −67 mV and tafel slope of 38 mV.dec−1. Scanning Electron Microscope (SEM) observations and Cyclic Voltametry (CV) electrochemical tests showed that morphology had a negligible effect on electrocatalytic performance of the coating. In addition, the presence of alloying elements improved the coating intrinsic properties by changing its electronic structure. Electrocatalytic stability was assessed using chronoamperometry, cyclic voltammetry, and stepwise chronoamperometry tests, introducing NWMCP sample a durable electrode generation with good stability.

DEPOSITING Ni–Co–P ALLOY COATING ON AISI316 STEEL AND ANALYZING ITS PROPERTIES

After appropriately preparing the surface of AISI316 steel, the Ni–Co–P coating layer was deposited on the substrate using the electroless method using baths with different mole ratios of CoSO4/NiSO[Formula: see text]. Coating rate, weight percentage of the alloy elements, corrosion rate and coating layer hardness were studied in the achieved coating layers. The coating rate of the Ni–Co–P coating layer is a function of the mole ratio of CoSO4/CoSO[Formula: see text], sodium hypophosphite concentration, bath temperature, bath pH and plating time. The electroless deposits studied in this paper are in crystal form. The XRD pattern of the Ni–Co–P deposits shows the peaks related to Ni-fcc and tetragonal Ni[Formula: see text]P5. X-ray diffraction pattern confirms the formation of the Ni3P phase during annealing for 1[Formula: see text]h at 400∘C.

Morphological studies of Si nanowires effect on the photovoltaic s

Silicon nanowires (SiNWs) were produced by an electroless method on FZ-Si (100) wafer, in HF/AgNO3 solution. The influence of etching time and temperature on SiNWs morphology were studied using FESEM images. Optical properties were also investigated by optical absorption spectroscopy and low-temperature photoluminescence at 4.2 K. Considering their role as active regions, photo- voltaic properties of SiNWs solar cells were studied for their different lengths. Photovoltaic measurements were taken in 1 sun condition under AM 1.5 illumination supplied by a solar simulator. Measurements indicated a reduction in effi ciency as SiNWs length increased, which might be attributed to increased dangling states on nanowires surfaces.

Application of textile (PAN-based) activated carbon fibers decorated with silver nanoparticles in water treatment

Introduction: Water treatment deficit and poor health, hygiene and sanitation infrastructure can contribute to disease transmission by dissemination of contaminants and microorganisms. As an alternative, carbon-based materials coated with antimicrobial molecules have been proposed for water treatment, but few supporting data are available so far. Hence, this study investigates the potential use of PAN-based activated carbon fibers (ACF) decorated with silver nanoparticles in water treatment.Methods: Silver nanoparticles were incorporated into the material using a cheap and electroless method. Field emission scanning electron microscopy (FEGSEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) characterized the whole material. The textile was mounted on a water filter prototype and had its capacity to remove bacterial (Escherichia coli) and fungal (Candida albicans, Aspergillus niger and Penicillium funiculosum) cells evaluated. Composition and toxicity of the filtered water were determined.Results: Water filtered by Ag@ACF for 2 and 24 h contained 0.254 mg/L and 0.964 mg/L Ag, respectively. Ag@ACF filtering successfully removed E. coli, C. albicans, and A. niger from the suspensions, but not P. funiculosum. Treated water was non-toxic for Vero cells and Drosophila melanogaster, but toxic for Raphidocelis subcapitata. Ag@ACF showed efficient microbial elimination when applied in water treatment. Silver nanoparticles released in aqueous medium may be responsible for R. subcapitata toxicity. Future studies should be conducted to reduce silver nanoparticles release from the carbon fiber.

“Optimization and Characterization of Ni-B Coating of Using RSM Method”

Abstract: It is unique properties, the electroless method is used as an effective and important technique to create uniform coatings. Among the coatings that can be made by electroless process is Ni-B coating due to its excellent properties such as good corrosion resistance, high wear resistance, high hardness, favorable oxidation resistance. In this article, after introducing nickel-boron electroless coatings and examining the microstructure and wear rate, recent developments in strategies to improvement in corrosion resistance, tribological properties, and the use of nickel-boron electroless coatings as electrocatalysts. In this study operating parameters are optimized by using RSM method. operating parameters considered for the Reinforcement, temperature and frequency. This paper summarized, the parametric influence of Reinforcement, temperature and frequency on wear rate of Ni-B with ZrSi coating. Response surface methodology (RSM) is used for modelling and optimization. ANOVA has been carried out to identify importance of the operating parameters on the performance characteristics considered. Further the verification experiment has been carried out to confirm the performance of optimum parameters. The results from this study will be useful for selecting appropriate set of process parameters to Ni-B coating has been selected. The analysis of variance (ANOVA) has been used to determine effect of each parameter on wear rate so Finally, the confirmation test has been carried out to compare the predicted value of wear rate with the experimental value.

MICROSTRUCTURE, MECHANICAL PROPERTIES AND WEAR BEHAVIOR OF NI-COATED CONTINUOUS CARBON FIBER-REINFORCED A356 ALUMINUM MATRIX COMPOSITES FABRICATED BY SQUEEZE CASTING

In this research, aluminum matrix composites reinforced with continuous carbon fibers (CFs) were fabricated using A356 aluminum alloy and PAN-based CFs by squeeze casting. For this purpose, CFs were first coated with a nickel layer using the electroless method and then the microstructure of the nickel–phosphorus (Ni–P) electroless coating was investigated. In the next step, composite samples reinforced with volume fractions of 5, 10, and 15 vol.% CFs coated with Ni–P coating were fabricated by squeeze casting at 60 MPa, and then microstructure and mechanical properties were examined. The results of the bending test on the composite samples indicated that the nickel coating had a significant effect on the flexural strength of the composite and increased the flexural strength by up to 30%. In addition, with the increase in the volume percentage of the fibers, the hardness of the samples increased while both the wear rate and the coefficient of friction decreased. Moreover, the best wear resistance was observed in the sample containing 15 vol.% as-coated carbon fibers. The Ni coating led to the formation of a mechanically mixed layer (MML) containing a fine mixture of metallic oxides and carbon thus enhancing the wear resistance.