Pulse Electrodeposition Method Research Articles

3D Nanostructured Electrodes based on Anodic Alumina Templates for Stable Pseudo‐capacitors

This study investigates the preparation of nickel nanostructured electrodes for the enhancement of supercapacitor (SC) performance. The nanostructured electrodes were synthesized using nanoporous anodic aluminium oxide (NAA) as a template via the pulsed electrodeposition method. Structural properties were examined using field‐emission scanning electron microscopy (FESEM), while electrochemical characterization was conducted through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results reveal that Ni nanorod arrays can be obtained embedded in the NAA matrix and with electrical contact with the aluminium substrate. On average, the rods are spaced 90 nm apart, with a diameter of 70 nm and a length of 2 µm. The Ni@NAA electrode exhibit an enlarged active area and exceptional electrochemical performance, demonstrating remarkable stability over 5000 cycles of CV at a scan rate of 50 mV·s‐1. Specific capacitance values exceeding 100 mF·cm‐2 and maximum charging times of less than 10 minutes are reported, highlighting its suitability for high‐power energy devices requiring pseudo‐supercapacitance. The study underscores the significance of nanostructured electrodes in advancing energy storage technologies and presents promising prospects for practical applications.This article is protected by copyright. All rights reserved.

In situ electrodeposited Zn-doped CoNiS as an efficient and stable electrocatalyst for overall water splitting in neutral media

Zinc-doped cobalt nickel sulfides coupled with polypyrrole hollow nanospheres grown on carbon paper (Zn-CoNiS/PHS/CP) were developed by unipolar pulse electrodeposition (UPED) method as efficient and stable electrocatalysts for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and overall water splitting in neutral media for the first time. With abundant active sites intrigued by moderate Zn doping, the optimized Zn10-CoNiS delivers improved catalytic performance with small overpotentials of 213 mV and 414 mV to achieve the current densities of 10 mA cm−2 for HER and OER respectively, and outstanding long-term stability. The water electrolyzer device with Zn10-CoNiS as both anode and cathode delivers a current density of 10 mA cm−2 at a cell voltage of 1.896 V in neutral media. The low charge transfer resistance of Zn-CoNiS and confinement effect of 2D Ni9S8/Co9S8 nanosheets on 0D ZnS nanodots endow the bifunctional electrocatalysts with efficient activity and high stability, providing a competitive candidate for green hydrogen production.

A novel carbon coating by electrochemical deposition in deep eutectic solvent with the assistance of ammonium chloride for stainless steel bipolar plates

In this work, pulse electrodeposition method was proposed to directly deposit amorphous carbon coating (ACC) onto 316L stainless steel substrate in choline chloride-ethylene glycol deep eutectic solvent (DES) mixed with ammonium chloride (NH4Cl) to fabricate bipolar plates. The obtained dense ACC has a thickness of ∼400 nm. Potentiodynamic and potentiostatic polarization tests demonstrated that the corrosion current density of ACC coated 316L steel was of the order of 10−7 A cm−2 in the simulated proton exchange membrane fuel cells (PEMFC) working environment, and the self-corrosion potential of the coating positively shifted by 0.4V, indicating a significant improvement on corrosion resistance of the coated steel plate due to excellent electrochemical stability of ACC. The Rockwell C indentation test showed that the as-obtained ACC was strongly bonded to the substrate and also had high in-plane strength. Further numerical simulation and comparison experiments showed that C was chemically bonded with Fe in the substrate, which was boosted by the assistance of NH4Cl. The intact and strong bonding between ACC and the substrate is highly helpful to improve corrosion resistance. The success in coating stainless steel plate with ACC by pulse electrodeposition method provides a promising alternation for coating of proton exchange membrane electrolyzer cell (PEMEC) and PEMFC metal bipolar plates.

Influence of Duty Cycle on the Phosphorus Content and Hardness of the Ni-P Coatings Produced by Pulse-Current Electroplating

Ni-P coatings were prepared on low carbon steel substrates using the pulse electrodeposition method. The influence of the pulse duty cycle on the phosphorus content and hardness of the Ni-P coatings was investigated. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were employed to examine the surface morphology and chemical composition of the Ni-P coating layers. The results showed that an increased pulse duty cycle (20% - 80%) led to a decreased phosphorus content from 17.81 wt.% to 13.71 wt.%. The microhardness values were found to have an inverse relationship with the phosphorus content. The highest hardness of 538.22 ± 12.92 HV0.1 was obtained from the sample produced with a duty cycle of 80%, which had the lowest P content of 13.71 wt.%.

Investigation on the electrocatalytic oxidation of alcohol using zinc oxide thin films deposited by pulsed electrodeposition on an indium tin oxide surface

To perform electro-catalytic oxidation of alcohols in an alkaline media, zinc oxide (ZnO) thin films were effectively deposited on indium tin oxide (ITO) substrates using the pulsed electrodeposition (PE) method in a zinc nitrate aqueous solution. Analyses of microstructural, photoelectrochemical, and optical characteristics of ZnO thin films were performed as a function of pulsed electrodeposition parameters. XRD analysis was applied to determine structural properties, and SEM and AFM analysis were used to investigate morphological characteristics. X-ray diffraction analyses revealed that the produced films were polycrystalline and had a (002) preferentially oriented, hexagonal wurtzite structure. The morphology of ZnO has improved in the direction of nanorod films, as evidenced by scanning electron microscopy (SEM) and atomic force microscopy (AFM) images. UV transmittance data was used using Tauc's relationship to determine the film's bandgap to be 3.26 eV. The photocurrent response shows that ZnO films have high values, at 305.17 A/cm2, and good optical characteristics. The electrocatalytic oxidation of methanol was finally evaluated on the films. After being optimized in the pulsed electrodeposition mode, ZnO thin film characteristics and methanol electrocatalytic oxidation both saw substantial improvements.

Pseudo lamellae of Cu6Sn5 on the crystal facet of Sn in electrodeposited eutectic Sn-Cu lead-free solder

Eutectic Sn-Cu lead-free solder is developed using the pulse electrodeposition method from a citrate bath at different current densities like 0.1, 0.2, 0.4, and 0.5 A/cm2. The exact composition of all the deposits was confirmed through atomic absorption spectroscopy (AAS) analysis. The coating deposited at 0.2 A/cm2 constitutes 0.7 wt% of Cu which is similar to the eutectic Sn-Cu composition. Microstructural characterization was carried out with the help of a scanning electron microscope (SEM). Sn was the major constituent in all the deposits while a little amount of intermetallic i.e. Cu6Sn5 was present for the deposits at 0.1 and 0.2 A/ cm2. The energy dispersive spectroscopy (EDS) results showed traces of Cu6Sn5 in the deposits. The formation of Cu6Sn5 was also confirmed through X-ray diffraction (XRD). For the deposit at 0.2 A/cm2, the endothermic peak temperature in DSC is exactly the same as that of the melting point of Sn-Cu eutectic. This electrodeposited microstructure resembles the conventional eutectic Sn-Cu cast structure. The top view of the deposited Cu6Sn5 on the steps of Sn creates an illusion of lamellar structure. The effect of current density on the roughness was analyzed through AFM.

Investigation and Improvement Strategies for Mold Fracture: A Study on the Application of a Pulse Electrodeposition Method for Enhancing Mold Lifespan

An investigation on the fracture of a mold, comparing it with a normal part using specific techniques, such as EDX, SEM, and AES, is presented in this study. The EDX analysis revealed that the composition of the normal part was consistent with that of low-carbon steel, mainly comprising Fe and C. In contrast, the fractured part exhibited cracks due to nonconforming nonmetallic inclusions and reticular carbides, with fractures resulting from microporosity agglomeration and cleavage fracture. The SEM and AES analyses further presented the causes of mold fracture, highlighting the mechanism by which the dimples on the specimen edge contributed to the fracture. The EDX analysis confirmed that the mold experienced thermal brittleness during use. To enhance mold durability and extend its lifespan, a pulse electrodeposition method was employed to create a NiCo alloy coating as a replacement for the Cr layer on the metal surface. The coating exhibited a smooth and scratch-free surface. The prepared NiCo special coating significantly increased the mold yield strength by approximately 313.8%, facilitated a 13% increase in plastic deformation, and reduced the fracture strain by 25%, effectively preventing mold fracture and improving its service life.

Fabrication and magnetic properties of pulse electrodeposited FeSn nanowire arrays

When it comes to fabricating efficient nanomaterials for magnetic recording media and spintronic devices, Fe-based nanowires (NWs) containing nonmagnetic elements can represent themselves as one of ideal candidates. Here, a pulse electrodeposition method in porous anodic alumina membranes is employed to fabricate Fe100-xSnx (2 ≤ x ≤ 68) NW arrays with a diameter of about 35 nm. During the NW fabrication, Sn electrolyte concentration (CSn) and off-time (Toff) between pulses change in the range from 0.0025 to 0.02 M and 0–75 ms, respectively. As a general trend, magnetic properties including coercivity and squareness values decrease with increasing the Sn content. Meanwhile, first-order reversal curve diagrams show single domain and pseudo-single domain states of the FeSn NWs, depending on the Sn content in the structure dominated by Fe or FeSn alloy crystal phase. Magnetostatic interactions and coercive field distributions are also observed to significantly change by varying CSn and Toff, providing magnetically tunable FeSn NW arrays induced by the nonmagnetic element addition.

Chemically-stable flexible transparent electrode: gold-electrodeposited on embedded silver nanowires

Silver nanowires (AgNWs) with a low diameter, high aspect ratio, stable suspension, and easy synthesis have recently attracted the optoelectronic industry as a low-cost alternative to indium tin oxide transparent conductive films. However, silver nanowires are not chemically stable, and their conductivity diminishes over time due to reactions with atmospheric components. This is a bottleneck for their wide industrial applications. In this study, we aim to address this issue by synthesizing silver nanowires with an average diameter of approximately 65 nm and a length of approximately 13 µm. The prepared Ag nanowires are then applied to fabricate transparent, flexible, and chemically stable conductive films. The fabrication includes spraying of silver nanowires suspension on a glass substrate followed by Dr. blade coating of polystyrene (PS) solution and delamination of the PS-AgNWs film. The resulting film exhibits an optimum sheet resistance of 24 Ω/□ and transmittance of 84%. To further enhance the stability of the transparent conductive film, the facial and scalable double pulse electrodeposition method is used for coating of gold on the exposed surface of the AgNWs embedded in PS. The final transparent film with gold coating demonstrates a remarkable stability under harsh conditions including long exposure to UV light and nitric acid solution. After 100 min of UV/Ozone treatment, the increase in sheet resistance of the optimal PS-AgNW@Au sample is 15.6 times lower than the samples without gold coating. In addition, the change in sheet resistance after 2000 bending cycles in the optimal PS-AgNW@Au electrode is measured and it showed an increase of only 22% of its initial sheet resistance indicating its good flexibility. The proposed electrode performs an excellent chemical stability, good conductivity, transparency, and flexibility that makes it a potential candidate for various optoelectronic devices.

Nanoscale hydroxyapatite/chitosan polymer coatings: Synthesis and characterization

AbstractThe present work involves the coating synthesis of nano‐hydroxyapatite/chitosan (nHA/CS) on a Mg‐2 wt% Zn scaffold with the pulse electrodeposition (PED) technique. In practice, to render coatings more corrosion‐resistant and biocompatibility in simulated body fluids, the impact of PED factors, such as mean current density (j), a duty cycle, and coating duration (t), was investigated. Further, Fourier transform infrared spectroscopy, scanning electron microscope, x‐ray diffraction, energy‐dispersion spectrometer, and water contact angle (WCA) were studied to characterize coatings. The corrosion resistance of coatings was investigated by impedance evaluations and potentiodynamic polarization. The results obtained from analyses revealed that the optimum conditions for synthesizing the nHA/CS coating were achieved when applying j = 20 mA/cm2, a duty cycle = 0.4, and a duration of 60 minutes. The coatings' microstructure and Ca/P ratio were influenced by PED factors, which included nano spherical‐shaped and 1.65. Furthermore, the corrosion rate was decreased from 19.603 to 1.492 mm yr−1 after being modified by optimum coating. Moreover, the high hydrophilic properties are assigned to this coating with a WCA of 29.9 compared to other coatings and the Mg scaffold. The biological properties of the optimum coating were assessed through in‐vitro experiments involving MG63 cells, which included the evaluations of cell adhesion and cytotoxicity. The results obtained from the corrosion and in‐vitro experiments indicate that the nanocomposite coating, upon optimization, holds potential as a scaffold for bone tissue engineering.Highlights Using Mg‐2 wt% Zn scaffold as a substrate for nanocomposite coatings. Pulse electrodeposition method for the synthesis of nano‐hydroxyapatite/chitosan (nHA/CS) coatings. Pulse electrodeposition (PED) method to modify morphology, corrosion resistance, and biocompatibility. Optimum PED parameters: j = 20 mA/cm2, duty cycle = 0.4, and t = 60 min.

Study on Ni+W Combined with SiC Nanocoatings Prepared using Pulse Electrodeposition Method

Study on Ni+W Combined with SiC Nanocoatings Prepared using Pulse Electrodeposition Method

Pulsed current electrodeposition of gold nanostructures on ITO: Control of particle density and optical transmission

With the advance in the plasmonics and metamaterials research field, it has become increasingly crucial to fabricate thin Au metal films cost-effectively and reliably. Here, we study the deposition of gold nanostructures onto the ITO surfaces, using the pulsed current electrodeposition (PED) method, with a pre-seeding step. It was demonstrated that Au nanostructure (AuNS) particle lateral sizes, when deposited onto ITO surfaces, are influenced by deposition current. The lateral size of the particles was found to affect the AuNS density and final form of the film. The study's findings also show that dense films (c.a. 75 %) of Au nanostructures with a thickness of around 5 nm can be formed using the PED method with an optimum current density of 2 A/dm2. Furthermore, the AuNS density has been shown to have a strong influence upon the resulting electrical conductivity and transmittance of the films in the visible and near-infrared wavelength.

Preparation and characterization of PMT-TiO2-NTs@NiO–C/Sn–Sb composite electrodes by a two-step pulsed electrodeposition method for the degradation of crystalline violet

To overcome the limitations imposed by Sn–Sb electrodes, the titanium foam (PMT)-TiO2-NTs@NiO–C/Sn–Sb composite electrodes with cubic crystal structure are synthesized by introducing NiO@C nanosheet arrays interlayer on the TiO2-NTs/PMT matrix through hydrothermal and carbonization process. Then a two-step pulsed electrodeposition method is used to prepare the Sn–Sb coating. Benefiting from the advantages of stacked 2D layer-sheet structure, the obtained electrodes exhibit enhanced stability and conductivity. Synergy of inner and outer layers fabricated by different pulse times strongly influence the electrochemical catalytic properties of the PMT-TiO2-NTs@NiO–C/Sn–Sb (Sn–Sb) electrode. Hence, the Sn–Sb (b0.5 h + w1 h) electrode is the optimal electrode to degrade the Crystalline Violet (CV). Next, the effect of the four experimental parameters (initial CV concentration, current density, pH value and supporting electrolyte concentration) on the degradation of CV by the electrode are investigated. The degradation of the CV is more sensitive to alkaline pH, and the rapid decolorization of CV when the pH is 10. Moreover, the possible electrocatalytic degradation pathway of CV is performed using HPLC-MS. Results from the tests show that the PMT-TiO2-NTs/NiO@C/Sn–Sb (b0.5 h + w1 h) electrode is an interesting alternative material in industrial wastewater applications.

How the duty cycle affects wear and corrosion: A parametric study in the Ni–B–TiN composite coatings

TiN-reinforced Ni–B composite coatings were synthesized in the watts bath using pulse electrodeposition method at different duty cycles of 20%, 40%, 60%, and 80%. The surface morphology, phase structure, hardness, wear, and corrosion behavior of the coatings produced at different duty cycles were examined. The effect of the duty cycle on the microstructure of the composite coating was investigated using scanning electron microscopy (SEM) analysis. Depending on the duty cycle, a coating thickness of ∼69.7μm was obtained on the cathode surface. Crystallite size and lattice distortion of coatings were calculated with X-ray diffraction (XRD) data. The nano-indentation hardness results showed that the high nucleation rate at 40% duty cycle increased the coating hardness to 1170 HV. The wear test results indicated that the distribution of TiN particles in the coating content reduced the wear rate of the coating to 2.121 × 10−5mm3/Nm. Corrosion tests performed in 3.5 wt.% NaCl solutions were analyzed by Tafel curves and electrochemical impedance spectroscopy (EIS). Depending on the duty cycle/reinforcement particle distribution relationship, icorr and Ecorr values were measured as 2.27x10 −6 (A/cm 2) and -0.427 V, respectively.

Pulsed electrodeposition of MXenes/HAp multiple biological functional coatings on 3D printed porous Ti-6Al-4V bone tissue engineering scaffold

Titanium and its alloys have been widely used as bone tissue engineering scaffold due to their excellent biocompatibility and mechanical strength. In order to promote bone ingrowth, integration and match the mechanical properties of natural bone tissue, this study proposed diamond-like microstructure porous Ti-6Al-4V scaffolds for personalized bone defect repair. In order to prepare the multiple biological functional coatings on the curve surface inside of the 3D printed porous scaffolds, pulsed electrodeposition method was proposed to obtain multiple layers of Ti3C2Tx/HAp composited coatings. Delaminated Ti3C2Tx has an ultra-thin microstructure according to transmission electron microscopy (TEM) observation and is well dispersed in electrolyte. X-ray diffraction (XRD) characterization shows that Ti3C2Tx has been synthesized and regulates more CaHPO4‧2H2O (DCPD) to Hydroxyapatite (HAP) conversion, which is confirmed by Fourier transform infrared spectroscopy (FTIR) at 0.2 mg/mL concentration. Scanning electron microscopy (SEM) shows that the morphologies of composite coatings are closely related to Ti3C2Tx content due to the availability of effective voltages for electrodeposition. By means of finite element method, deposition thickness and distribution of coatings were simulated to explore the precipitation kinetics and selection of electrodeposition parameters and a current density of 15 mA/cm2 was ultimately used. In vitro electrochemical corrosion of Ti3C2Tx/HAp coatings were tested in human simulated body fluid (SBF) to verify its corrosion resistance in physiological environment and Ti3C2Tx/HAp composited coatings possess the best corrosion resistance according to linear scanning voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) tests. In vitro MC3T3-E1 cell culturing studies were investigated to evaluate cell behaviors and biocompatibility of these coatings. The results indicate that cells grow well on the surface of composite coatings without showing cytotoxicity and cell morphologies show a good spreading state and a trend of inward growth.

Nanostructured MnO2 Films for 3D Micro‐Supercapacitors: From New Insights of the Growth Mechanism to the Fine Tuning of Areal Capacitance Values

Maximizing the electrochemical performance of 3D micro-supercapacitors based on pseudocapacitive films is crucial for powering the next generation of miniaturized IoT devices. The films have to be nanostructured, must conform the 3D template, and have uniform deposition. To study the growth mechanism of nanostructured MnO2 films obtained by a pulsed electrodeposition method, in situ Atomic Force Microscopy methods operating in liquid mode, Scanning Electron Microscopy, and electrochemical characterization techniques were used. The impact of ON and OFF times during the pulsed electrodeposition process was investigated. The deposition mechanism in Volmer Weber Island growth mode provided some guidelines to tune the deposit morphology to enhance the electrochemical performance of the 3D electrode based on nanostructured MnO2 films.

Preparation and Characterization of Pulse Electrodeposited Ni/W-SiC Nanocomposite Coating on Mild Steel Substrate

In order to improve the performances of metal containers, furnace bodies and agricultural tools manufactured by mild steels, Ni/W-SiC nanocomposites are prefabricated on mild steel substrate by the pulse electrodeposition (PED) method. The morphology, texture, microstructure, microhardness, and wear performances of Ni/W-SiC nanocomposites are examined by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), dispersive X-ray spectroscopy (EDX), hardness tester, and friction wear testing. The results indicate that the SiC size in nanocomposites is ~32.4 nm when its concentration in electrolytes is 7 g/L. The S1 and S4 nanocomposites’ microstructures (the S1 composite was prefabricated at 4 g/L, and the S4 composite was deposited at 13 g/L) reveal many large cauliflower-shaped grains. However, the S2 nanocomposite (the S2 composite was obtained at 7 g/L) demonstrates the homogeneous, finest and smoothest surface morphology. The diffraction angles of S1 nanocomposite are 41.2°, 51.7°, and 71.2° depicting the sharpest diffraction peaks, corresponding to the (1 1 1), (2 0 0), and (2 2 0) crystal planes of Ni-W grains, respectively. Moreover, the S2 nanocomposite exhibits the lowest wear depth and width of 34.2 μm and 5.5 mm, respectively. Some shallow and fine scratches on the as-described nanocomposites’ surface indicate its excellent tribological performance. However, the S4 nanocomposite exhibits a wear depth of 86.3 μm and a width of 11.9 mm.

Fabrication of corrosion-resistant conversion coating based on ZIF-8 on electro-galvanized steel utilizing pulse electrodeposition technique

In this work, through a novel method of synthesizing zeolitic imidazolate framework-8 (ZIF-8), a conversion coating (CC) was applied to a galvanized surface. A reverse pulse electrodeposition (PED) method was employed to apply ZIF-8 conversion coating in a 2-methylimidazole bath during 2, 4, and 6 h. Characterization techniques demonstrated that the ZIF-8 conversion coating (ZIF-8CC) was successfully synthesized after 6 h. The increase in hydrophilicity of the synthesized conversion coating was demonstrated by the contact angle test. The best performance of the single-layer conversion coating against corrosion was obtained in the case of ZIF-8CC@6 h. Then, an epoxy coating was applied to the samples with and without conversion coatings. The effect of the ZIF-8 conversion coating on the adhesion strength and the corrosion behavior of the epoxy coating was investigated. The results revealed the superior functioning of ZIF-8CC@6 h compared to the rest of the samples in terms of adhesion and protective performance of the epoxy coating.

The effect of TiO2 concentration on morphology, wear and corrosion properties of NiB-TiO2 composite coatings by ultrasonic-assisted pulse electrodeposition

In this study, TiO2 particle reinforced NiB alloy matrix composite coatings were produced on steel substrates by using a modified Watts type bath with ultrasonic-assisted pulse electrodeposition (UAPED) method. The average particle size of the TiO2 particles used in the composite coating is 500 nm, and the effect of different particle concentrations (0, 5, 10, 15 and 20 g l−1) on mechanical and electrochemical properties was investigated. The produced NiB alloy and NiB-TiO2 composite coatings were heat treated at 400 °C for 2 h, and the properties of the coatings were compared before and after heat treatment. Microstructure and morphology were characterized by scanning electron microscope (SEM). Phases and structures were determined by x-ray diffraction analysis (XRD), and crystalline size and % distortion were calculated from XRD analysis. The hardness measurements of NiB alloy and NiB-TiO2 composite coatings were carried out by microhardness measurement, and the wear tests of composites were carried out by the reciprocating method. Electrochemical measurements of coatings were carried out in 3.5% NaCl solution, and the effect of particle concentration on corrosion behaviour was investigated. The highest hardness value was 1268 HV, and it was obtained at 20 g l−1 TiO2 concentration and after heat treatment. The lowest crystalline size was obtained 34.4 nm with NiB-TiO2 composite coatings. When the wear resistances were compared with NiB-TiO2 composites and NiB alloy coating, composite coatings’ wear resistance increased approximately two times with the effect of heat treatment. In addition, when the coatings are evaluated in terms of corrosion behaviour, the best result was obtained in the composite coating produced with 20 g l−1 TiO2 concentration. Compared to NiB Alloy coating, the corrosion rate of the composite coating produced with 20 g l−1 TiO2 concentration was reduced from 32.49 mpy to 11.68 mpy. This indicates an improvement of approximately three times in corrosion rate.

Retraction: Investigation on corrosion protection and mechanical performance of minerals substituted hydroxyapatite coating on HELCDEB-treated titanium using pulsed electrodeposition method.

[This retracts the article DOI: 10.1039/C4RA04484C.].