Simple One-step Electrodeposition Research Articles

The mechanism of enhanced electrocatalytic water splitting on S-doped NiFe2O4/Ni–Fe alloy@copper foams

The development of bifunctional catalysts with subtle structures, high efficiencies, and good durabilities for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is crucial for overall water splitting. In this work, a multicomponent S-doped NiFe2O4/Ni–Fe micro nano flower electrocatalyst was synthesized rapidly on foam copper using a simple one-step constant current electrodeposition method. The introduction of S leads to the transformation of the microsphere structure of the Ni–Fe alloy into a cauliflower-like morphology and induces changes in the surface electronic structure, significantly enhancing the catalytic performance for the HER and OER. The S-NiFe2O4/Ni–Fe alloy/CF showed low overpotentials of 220 and 66 mV at 10 mA cm−2 in 1.0 M KOH for the OER and HER, respectively. High durability OER and HER performances were demonstrated through 60 h of chronopotentiometry and 6000 CV cycles test. Excellent overall water splitting electrocatalytic activity was observed in the S-NiFe2O4/Ni–Fe alloy/CF‖S-NiFe2O4/Ni–Fe alloy/CF two-electrode system. In particular, active-phase NiOOH, a highly active substance for OER, can be controllably formed in the reaction process owing to the nanoflower structure of multi-layer sulfur which slows down the dissolution of NiFe2O4/Ni–Fe alloy. These results suggest that this composite structure is a promising bifunctional electrocatalyst.

One-step electrodeposition of bifunctional MnCoPi electrocatalysts with wrinkled globular-flowers-like structure for highly efficient electrocatalytic water splitting

The development and exploration of electrocatalysts with the high reactive and abundant availability is still extremely crucial in electrocatalytic overall water splitting. Herein, a novel globular-flowers-like MnO2/Co3(PO4)2 (denoted as MnCoPi) electrocatalyst on nickel foam was successfully prepared through a simple one-step electrodeposition method. The MnCoPi electrocatalyst simultaneously delivers remarkable electrocatalytic activities for hydrogen evolution reaction (HER) with overpotentials (η10) reaching 102 mV and oxygen evolution reaction (OER) with overpotentials (η10) up to 225 mV in 1 M KOH solution. Furthermore, the assembled electrolyzer cell utilizing MnCoPi as the cathode and anode only requires a low voltage of 1.55 V to achieve a current density of 10 mA cm−2. Moreover, the developed MnCoPi electrocatalyst shows excellent stability during continuous operation for 48 h in OER, HER and overall water splitting process. Compared with the pristine MnO2, the significant electrocatalytic properties of MnCoPi can mainly be attributed to the improved physicochemical properties such as distinctive globular-flowers-like morphology, huge specific surface areas and abundant porosity structure, low electrochemical resistance, especially for the formed heterojunction between MnO2 and Co3(PO4)2, which can provide abundant reactive sites and accelerated electron transfer, etc. Consequently, this work provides a new avenue for the development of efficient and stable bifunctional electrocatalysts for overall water splitting.

One-step electrodeposition synthesis of NiFePS on carbon cloth as self-supported electrodes for electrochemical overall water splitting

Electrocatalytic water splitting (EWS) for hydrogen production is considered an ideal strategy for utilizing renewable energy, reducing fossil fuel consumption, and addressing environmental pollution issues. Traditional noble metal electrocatalysts have excellent performance, but their cost is high. Developing efficient, stable, and relatively inexpensive dual functional electrocatalysts is crucial for promoting large-scale EWS hydrogen production processes. Herein, a simple one-step electrodeposition method was used to grow nickel–iron phosphorus-sulfides (NiFePS) on the surface of hydrophilic treated carbon cloth (CC). The resultant NiFePS/CC with a phosphorus to sulfur ratio of 1:4 exhibited the best electrocatalytic performance, requiring only −91 mV and 216 mV overpotentials to generate the current densities of 10 mA·cm−2 in hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. When it was used as a bifunctional electrocatalyst to overall water splitting (OWS), a voltage of 1.536 V can generate a current density of 10 mA·cm−2. The excellent electrocatalytic performance can be ascribed to two factors: 1) the CC with excellent conductivity serves as a growth substrate, reducing the impedance of charge transfer from the electrode to the electrolyte and accelerating the electron transfer rate; 2) The large number of ultra-thin nanosheets formed on the surface of the catalyst increase the electrochemical specific surface area, expose more reaction sites, and thus improve the electrocatalytic reaction performance. This work provides a new approach for designing efficient non-noble metal electrocatalysts for water splitting.

Experimental investigation on the electrodeposited nickel-based dichalcogenides for the efficient overall water splitting

Layered transition metal dichalcogenides are effective electrocatalysts for water splitting due to their unique properties such as high electrical conductivity, active site density, and catalytic properties. This study focused on the deposition of Ni-based dichalcogenides (NiX2, where X = S, Se, Te) onto a carbon cloth substrate using a simple one-step electrodeposition method at room temperature with different deposition times (10, 15, and 20 min). The optimized NiS2-15, NiSe2-15, and NiTe2-15 electrocatalysts showed excellent bifunctional electrocatalytic activity for both hydrogen evolution reaction and oxygen evolution reaction in alkaline media. The overpotential values for hydrogen evolution were ∼56 mV, ∼37 mV, and ∼75 mV for NiS2-15, NiSe2-15, and NiTe2-15, respectively, while the overpotential values for oxygen evolution were ∼220 mV, ∼170 mV, and ∼210 mV, respectively. The electrocatalysts maintained stability for 24 h during the evolution reactions. The density functional theory calculations suggested that NiSe2 had a lower ΔGH* value due to its smaller bandgap and inherent metallic characteristics, which is consistent with the experimental results. These findings provide a new direction for designing NiX2 (X = S, Se, Te) nanosheets for electrocatalysis applications.

CoNiO2/Co3O4 Nanosheets on Boron Doped Diamond for Supercapacitor Electrodes.

Developing novel supercapacitor electrodes with high energy density and good cycle stability has aroused great interest. Herein, the vertically aligned CoNiO2/Co3O4 nanosheet arrays anchored on boron doped diamond (BDD) films are designed and fabricated by a simple one-step electrodeposition method. The CoNiO2/Co3O4/BDD electrode possesses a large specific capacitance (214 mF cm-2) and a long-term capacitance retention (85.9% after 10,000 cycles), which is attributed to the unique two-dimensional nanosheet architecture, high conductivity of CoNiO2/Co3O4 and the wide potential window of diamond. Nanosheet materials with an ultrathin thickness can decrease the diffusion length of ions, increase the contact area with electrolyte, as well as improve active material utilization, which leads to an enhanced electrochemical performance. Additionally, CoNiO2/Co3O4/BDD is fabricated as the positive electrode with activated carbon as the negative electrode, this assembled asymmetric supercapacitor exhibits an energy density of 7.5 W h kg-1 at a power density of 330.5 W kg-1 and capacity retention rate of 97.4% after 10,000 cycles in 6 M KOH. This work would provide insights into the design of advanced electrode materials for high-performance supercapacitors.

Effect of Strontium-Substituted Calcium Phosphate Coatings Prepared by One-Step Electrodeposition at Different Temperatures on Corrosion Resistance and Biocompatibility of AZ31 Magnesium Alloys.

As potential degradable biomaterials, magnesium (Mg) alloys have development prospects in the field of orthopedic load-bearing, whereas the clinical application has encountered a bottleneck due to a series of problems caused by its rapid corrosion. In this study, strontium-substituted calcium phosphate (CaP) coatings with different structures were prepared on the surface of the Mg matrix by a simple one-step electrodeposition method at different temperatures, which enhanced the poor corrosion resistance of the Mg matrix. The coated sample prepared at 65 °C reduced the corrosion current density by 3 orders of magnitude and increased the impedance by nearly 2 orders of magnitude compared with bare Mg alloy, thanks to its dense fibrous structure similar to that of natural bones. Although the coating composition varies with different preparation temperatures, CaP, as an inorganic component similar to natural bone, has good cytocompatibility. Doping the right amount of strontium, which is a trace element in human bones, is beneficial to stimulate osteoblast differentiation, inhibit the activity of osteoclasts, and induce the formation of bone tissues. This provides a new option for modifying the Mg alloy with CaP coatings as a base.

Ce and S co-doped NiFe based alloy nanocomposite prepared by one-step electrodeposition method for oxygen evolution reaction

It's still a challenge to design reasonably efficient catalyst using non-noble metal for the oxygen evolution reaction (OER). In this paper, we use a simple one-step electrodeposition method to load Ce and S co-doped NiFe amorphous alloys onto Cu(OH)2 nanorod arrays. The excellent oxygen electrocatalytic performance of the catalyst NiFeCeS/Cu(OH)2/CuF is attributed to the electronic environments of the active sites of Ni and Fe regulated by heteroatomic sulfur and cerium, which promote the transfer of the oxygen precipitation intermediates to the higher valence states. Meanwhile, the highly conductive substrate accelerates the electron transfer efficiency of the catalyst material, and the loose nanostructure increases the specific surface area, exposing more active sites. NiFeCeS/Cu(OH)2/CuF shows outsanding electrocatalytic activity for oxygen evolution with a low overpotential of 227 mV at a current density of 10 mA cm−2 in alkaline medium. Moreover, the nanocomposite catalyst also exhibits rapid reaction kinetics and long-term stability and durability. In this work, an efficient oxygen precipitation catalyst is reported, which indicates that non-precious metal-based electrocatalysts have great potential for application in water electrolysis and provides a basis for the rational design and synthesis of nanorod array catalysts with unique structures.

Heterogeneous Fe-doped Ni(OH)2 grown on nickel mesh by electrodeposition for efficient alkaline oxygen evolution reaction.

Designing highly excellent and stable catalysts for alkaline oxygen evolution reaction (OER) is gradually pivotal for clean energy development. In this work, a heterogeneous Fe-doped Ni(OH)2 (Ni/Fe-0.1) was developed via simple one-step electrodeposition onto nickel mesh. The heterogeneous interface structure generates sufficient active sites, significantly improving OER performance with an overpotential of 174 mV at 10 mA cm-2 (η10), while Tafel slope is only 43.0 mV dec-1. In particular, Ni/Fe-0.1 is still able to operate stably at a current density of 1 A cm-2 for 100 h without obvious potential decay. The oxidation of Ni2+ to Ni3+ was detected by X-ray photoelectron spectroscopy, proving that the heterogeneous catalyst could stabilize the high-valence state of nickel as active sites to its superior OER performance. This work provides a convenient synthetic strategy forforming heterogeneous catalysts toward efficient water electrolysis.

Corrosion-resistant superhydrophobic films on galvanized steel by one-step electrodeposition

A simple one-step electrodeposition method is proposed to fabricate corrosion-resistant superhydrophobic films on hot-dip galvanized steel without using low surface-energy materials. The effects of electrodeposition time on surface morphology, surface composition, surface roughness, wettability, and corrosion resistance of the electrodeposited zinc films were investigated. The results revealed that the morphological structures and roughnesses of the deposited zinc films were varied by the electrodeposition times. The roughened zinc films naturally reduced their surface energy during storage for 10 days as the formation of functional groups, transforming them to superhydrophobic and/or nearly superhydrophobic. The electrodeposited superhydrophobic films significantly enhanced the corrosion resistance of the hot-dip galvanized steel. Among them, the 20 min electrodeposition time gave the appropriate morphology and roughness to achieve a superhydrophobic surface with the optimum corrosion inhibition property.

Ultra-fast electrochemical preparation of Ni-Cu-Fe nano-micro dendrite as a highly active and stable electrocatalyst for overall water splitting

The development of highly active, durable, and low-cost electrocatalysts for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) to advance the commercial applications of overall water electrolysis is regarded as a crucial matter. We describe an ultra-fast synthesis of multi-metal Ni-Cu-Fe micro-nano dendritic electrocatalysts were synthesized on nickel foam using a simple one-step constant current electrodeposition method. According to DFT simulations, Fe incorporation causes a downshift movement in the d-band center and the formation of additional catalytic active sites. Ni-Cu-Fe nano-micro dendrites have potential applications as bifunctional catalysts for electrochemical water splitting. Also, the increased electrical conductivity of the Ni-Cu-Fe electrode is due to the placement of more electronic states near the Fermi level and creating an optimal and porous dendritic structure that causes better electrolyte penetration in the pores. Experiments show that in the 1.0 M KOH electrolyte, Ni-Cu-Fe catalysts need an ultra-low overpotentials of 42 mV and 300 mV to supply a current density of −10 mA cm−2 for the HER and 50 mA cm−2 for the OER. Also, when Ni-Cu-Fe electrocatalyst is used as a bifunctional electrode in the overall water splitting system, it displays a low cell voltage of 1.54 V in a current density of 10 mA cm−2 can maintain this activity for more than 100 h.

Facile electrodeposition synthesis and super performance of nano-porous Ni-Fe-Cu-Co-W high entropy alloy electrocatalyst

Establishing efficient nano-porous electrocatalysts for facilitating electron transfer is a one of the useful ways for enhance water splitting. Herein, Ni-Fe-Cu-Co-W high entropy alloy (NFCCW-HEA) electrocatalysts on the iron sheet substrate have been successfully prepared by a simple and efficient one-step electrodeposition method. High entropy alloys have a variety of active sites and unique atomic scale synergies, which makes the catalyst have good catalytic performance and stability. Meanwhile, the HEA coating like cauliflower by electrodeposition can provide more attachment sites, and significantly upgrade the OER catalytic activity. NFCCW-HEA catalysts exhibit an excellent overpotential of 247.3 mV under the current density of 10 mA·cm−2, and a low Tafel slope of 62.9 mV dec−1. The electrocatalyst shows long term stability of electrolysis for over 24 h in 1 mol·L−1 KOH alkaline solution, which shows good stability. We expect to provide a new idea for the preparation of nano porous high entropy alloy electrocatalysts by one-step electrodeposition technology.

Design of novel metal chalcogenide photoanodes supported with reduced graphene oxide for improvement of photoelectrochemical hydrogen evolution

Designing new photoanodeswith high efficiency provides an effective route to develop photoelectrochemical hydrogen production.In this work, quaternary metal chalcogenides (CdZnMSSe (M: Ni, Cu, Mo)) and reduced graphene oxide- quaternary metal chalcogenide (RGO-CdZnMSSe) composite films are fabricated by simple one-step electrodeposition process. The photoanodes formed of quaternary metal chalcogenides and the incorporation of RGO in these composite films increase charge transfer capability and separation ability compared to cadmium-based photoanodes, leading to enhancement of the photoelectrochemical hydrogen production activity. A superior photocurrent response is recorded for RGO(0.25)-Cd0.8Zn0.2Ni0.2S0.2Se0.8 (5.34 mA cm−2 at 0.8 V vs RHE). In addition, the maximum ABPE value of RGO(0.25)-Cd0.8Zn0.2Ni0.2S0.2Se0.8 is determined as 1.95%. The achieved results offer a new insight into highly efficient next generation-photoanodes to convert solar energy to hydrogen.

One-step electrodeposition to fabricate superhydrophobic surfaces on flexible conductive films: Optimization of metallic compounds

Superhydrophobic surfaces were fabricated by a simple one-step electrodeposition technique to deposit three distinct micro/nano hierarchical structures of Ce, Mg, or Cu-based compounds on Ag films on a flexible polymer substrate. Scanning electron microscopy was used to examine the surface morphologies of obtained structures with different deposition. Compared with the bare Ag films, one-step electrodeposition process resulted in superhydrophobicity, including a water contact angle of 159.7° for Ce-modified surfaces, 157.0° for Mg-modified surfaces, and 153.8° for Cu-modified surfaces. Besides, these surfaces showed high thermal stability below 120 ℃, and good flexibility but low electrical conductivity. EDS and XPS results suggest the production of low surface energy materials that formed the superhydrophobic features on the Ag films. Besides, because of the formation of CeO2, Ce-SHS had better superhydrophobicity than Mg-SHS and Cu-SHS. In addition, the potentiodynamic polarization experiments showed that the electrodeposited superhydrophobic surfaces had lower Icorr, higher Ecorr and impedance values in NaCl solution, Na2SO4 solution and Simulated body fluid, and artificial sweat solution compared with the bare silver film, indicating that the electrodeposited protective film has good anti-corrosion properties. These results suggest that the one-step electrodeposition method is a promising strategy to fabricate conducting films with superhydrophobic surfaces for surface protection under various corrosive environments.

Electrodeposition and analysis of thick bismuth films

Due to its unique physical and chemical properties, bismuth is an attractive candidate for a wide range of applications such as battery anodes, radiation shielding, and semiconductors, to name a few. This work presents the electrodeposition of mechanically stable and homogenous bismuth films at micron-scale thicknesses. A simple one-step electrodeposition process using either a pulse/reverse or direct current source yielded thick, homogenous, and mechanically stable bismuth films. Morphology, electrochemical behavior, adhesion, and mechanical stability of bismuth coatings plated with varying parameters were characterized via optical profilometry, cyclic voltammetry, electron microscopy, and tribology. Scratch testing on thick electroplated coatings (> 100 µm) revealed similar wear resistance properties between the pulse/reverse plated and direct current electroplated films. This study presents a versatile bismuth electroplating process with the possibility to replace lead in radiation shields with an inexpensive, non-toxic metal, or to make industrially relevant electrocatalytic devices.

Amorphous nickel–iron hydroxide nanosheets for effective electroreduction of nitrate to ammonia

Amorphous NiFe nanosheets synthesized through a simple one-step electrodeposition approach showed excellent activity and stability for selective ammonia synthesis by nitrate electroreduction.

Biomimetic platinum forest enables 3D micro-supercapacitors with enhanced areal performance

Nowadays, the rapid development of portable micro-electronics has stimulated a significantly increasing demand in micro-supercapacitors (MSCs) for efficient micropower sources. However, the performance of MSCs is hindered by the dense electrode design with sluggish ion diffusion or reaction kinetics and tortuous charge transfer pathways, especially at high mass loading. Inspired by the structure of natural forest with efficient solar energy utilization, we fabricate an innovative biomimetic Pt forest (named forest-like Pt) as a robust three-dimensional (3D) conductive current collector by a simple one-step electrodeposition process. This hierarchical nanoarchitecture significantly improves the exposed surface areas of active electrode materials. As a proof-of-concept, 3D MSCs based on poly(3,4-ethylenedioxythiophene) (PEDOT) conducting polymer grown on such forest-like Pt exhibit an enhanced areal capacitance of 69.3 mF cm−2 at 0.1 mA cm−2, which is more than 5-fold larger than that of pristine PEDOT-based MSCs using conventional flat Au current collectors. Furthermore, the assembled 3D MSCs show a high areal energy density (6.16 μW h cm−2) and outstanding rate capability (63.2 mF cm−2 even at 5 mA cm−2). Thus, this novel design concept provides a new approach to build advanced electrode nanoarchitectures for the next-generation MSCs.

Electrodeposited amorphous nickel–iron phosphide and sulfide derived films for electrocatalytic oxygen evolution

The preparation of inexpensive and efficient electrocatalysts for oxygen evolution reaction (OER) is crucial in the widespread application of water electrolyzers. A simple one-step aqueous electrodeposition method is utilized to prepare amorphous nickel-iron sulfide (Ni–Fe–S) and phosphide (Ni–Fe–P) films on Ni foam. The deposited films are highly porous, and can convert to active electrocatalysts for OER. In 1 M KOH, the Ni–Fe–S shows the highest OER activity, and requires only 230 mV overpotential to reach 0.05 A cm−2 OER current densities. The Fe–Ni–S also sustains the 30 h 0.05 A cm−2 galvanostatic OER test. Ex-situ characterizations show that sulfur in the Fe–Ni–S is oxidized and leached into the solution during OER, and that (oxy)hydroxide layer is formed at the surface. The adsorption energy of the hydroxyl group, an OER intermediate, is tuned by the electron interaction between the Ni and Fe, and the Ni–Fe–S exhibits the optimum hydroxyl group adsorption energy and the most facile OER kinetics. Also, higher intrinsic OER activity is observed for the electrodeposited amorphous nickel phosphide-derived film than the amorphous nickel sulfide-derived film.

Influence of CeO2 and TiO2 Particles on Physicochemical Properties of Composite Nickel Coatings Electrodeposited at Ambient Temperature.

The Ni-TiO2 and Ni-CeO2 composite coatings with varying hydrophilic/hydrophobic characteristics were fabricated by the electrodeposition method from a tartrate electrolyte at ambient temperature. To meet the requirements of tight regulation by the European Chemicals Agency classifying H3BO3 as a substance of very high concern, Rochelle salt was utilized as a buffer solution instead. The novelty of this study was to implement a simple one-step galvanostatic electrodeposition from the low-temperature electrolyte based on a greener buffer compared to traditionally used, aiming to obtain new types of soft-matrix Ni, Ni-CeO2, and Ni-TiO2 coatings onto steel or copper substrates. The surface characteristics of electrodeposited nickel composites were evaluated by SEM, EDS, surface contact angle measurements, and XPS. Physiochemical properties of pure Ni, Ni-CeO2, and Ni-TiO2 composites, namely, wear resistance, microhardness, microroughness, and photocatalytic activity, were studied. Potentiodynamic polarization, EIS, and ICP-MS analyses were employed to study the long-term corrosion behavior of coatings in a 0.5 M NaCl solution. Superior photocatalytic degradation of methylene blue, 96.2% after 6 h of illumination, was achieved in the case of Ni-TiO2 composite, while no substantial change in the photocatalytic behavior of the Ni-CeO2 compared to pure Ni was observed. Both composites demonstrated higher hardness and wear resistance than pure Ni. This study investigates the feasibility of utilizing TiO2 as a photocatalytic hydrophilicity promoter in the fabrication of composite coatings for various applications.

A one-step preparation of superhydrophobic stainless steel mesh and application in raffinate cleaning technology as a coalescer for contaminated organic-water separation

Improving raffinate oil-water separation efficiency and simplifying the production process of coalescing material are both in great demand but remain difficult. In this study, a superhydrophobic stainless steel surface was created using a simple one-step electrodeposition process in an electrolyte solution comprising nickel chloride (NiCl2·6H2O), stearic acid, and ethanol. The surface shape, chemical content, and superhydrophobic property were studied using a scanning electron microscope (SEM), Fourier-transform infrared (FT-IR) spectrometer, energy dispersive spectroscopy (EDS), and contact angle measurement. The cotton-like microstructure, comprised of crystals of Ni metal and Ni(CH3(CH2)16COO)2, demonstrated outstanding acid and alkaline resistance with a maximum surface contact angle of 166.8°. The oil-water separation performance of raffinate was tested in a mixer-settler, and the separation efficiency ranged from 75% to 80% in a P507 + Kerosene/water system, based on Chemical Oxygen Demand (COD) indicating its potential applicability in the solvent extraction process. A high-speed camera was also used to observe the coalescing behavior of oil droplets in water.

Corrosion and antimicrobial behavior of stainless steel prepared by one-step electrodeposition of silver at the grain boundaries

Introducing Ag to the surface is a common means to obtain an antibacterial product. However, the poor adhesion between coating and substrate often results in a non-durable antibacterial performance. Herein, we developed a simple one-step pulse-reverse electrodeposition method to introduce Ag particles into the grain boundaries of 304 stainless steel (304 SS) surface for a stable and long-acting antibacterial application. In the present method, the grain boundary was preferentially corroded as the potential “seat” for Ag particles, and the surface content of Ag upgraded to 0.57 at.% by optimizing the electrolyte, electrodeposition temperature, reaction time, and current density. Without deteriorating the corrosion resistance of the substrate, the 304 SS with Ag particles demonstrated considerable antibacterial properties against Escherichia coli and Staphylococcus aureus even after ultrasonic treatment or accelerated abrasion. Consequently, the current study proposes a facile strategy for the production of durable antibacterial stainless steel.