Electrochemical Co-deposition Research Articles

Electrocatalytic behavior of a mixed catalyst PdCu/Ag synthesized using electrochemical co-deposition and galvanic displacement

Electrocatalytic behavior of a mixed catalyst PdCu/Ag synthesized using electrochemical co-deposition and galvanic displacement

A high-power glucose fuel cell for potential application in implant surfaces

The glucose fuel cells (GFCs) leverage the implant surface as an electrode, representing an optimal approach for miniaturizing implantable power sources. A conductive hydrogel electrode membrane is crafted through in situ reduction and electrochemical co-deposition techniques by employing bacterial cellulose as a scaffold. This process enables the seamless integration of the GFC directly onto the implant surface. The integrated GFC exhibits an impressive open-circuit voltage peak of 0.894 V and a peak power density of 94.7 μW cm−2. Additionally, the fuel cell demonstrates resistance to chloride ion toxicity under simulated interstitial fluid conditions. Although performance within horse serum is moderate, the methodology presents a viable strategy for developing GFCs on implant surfaces.

Electrochemical diagrams showing equilibrium cathodic phases and their compositions as function of electrolyte composition and type of alloy phase diagram

In this paper the dependence of the elemental and phase compositions of the binary A-B cathodic deposits are computed by constructing “Electrochemical Diagrams”, abbreviated as ECDs, which potentially have a high practical significance. An ECD shows phases and compositions of cathodic alloy products as function of electrolyte composition at fixed temperature, pressure and at low current density upon galvano-static electrochemical co-deposition of components A-B from the same electrolyte on an inert cathode. The following rules are established here to construct the ECDs for binary A-B alloys: i). among all possible cathodic phases the one will be electrodeposited that provides the least negative cathodic deposition potential, ii). two or three (but not four or more) phases can be co-deposited on the cathode if their equilibrium cathodic potentials are equal and are the least negative among all possible cathodic phases, iii). the equilibrium compositions of solid and liquid A-B alloys that form on the cathode can be found from the condition of equality of the partial equilibrium cathodic potentials of components A and B. Based on the above three rules, ECDs are constructed for some basic types of binary equilibrium alloy phase diagrams with the composition of the alloy on its y-axes as function of the ionic composition of the electrolyte on its x-axes. In all cases the clear connection is shown between the ECDs and their corresponding alloy phase diagrams. The following geometric features are established for ECDs: i). solution phases are characterized by continuous curves, ii). phases of fixed compositions are characterized by horizontal lines, iii). two-phase mixtures are characterized by vertical lines, iv). three-phase equilibria are characterized by single points along the vertical lines corresponding to the two-phase equilibria of the parent phases of the third phase. It is shown that the restricted phase rule of Gibbs (= the maximum number of coexisting phases = the number of independent components + 1) is valid also for the ECDs. As examples, ECDs are calculated for the Ni-Co system and for the Ti-B system and good agreement is found between these calculated diagrams and the experimental data.

Molybdenum induced defective WO3 multifunctional nanostructure as an electrochromic energy storage device: Novel assembled photovoltaic-electrochromic Mo–WO3 film

In this work, a self-powered electrochromic device incorporating molybdenum-doped tungsten oxide (WO3) is developed for enhanced performances, offering a potential solution for energy efficient technologies. Defective nanostructure of WO3, enabled with molybdenum doping, is achieved through an electrochemical co-deposition method. A film of Mo–WO3 is investigated for multifunctional purposes, acting as both an electrochromic (EC) and energy storage device (ESD). As an EC film, it exhibits an optimal optical contrast of 84.5 %, minimum coloration time of 0.4 s, high coloration efficiency of 90.4 cm2/C, and excellent optical stability. In ESD applications, Mo–WO3 displays charge-transfer resistance of 7.6 Ω, a commendable capacitance of 39.1 mF/cm2, and excellent capacitance retention of 80.4 %. The integration of Mo ions into the WO3 nanostructure results in the formation of oxygen defect sites, which enhances the mobility of Li+ ions over the amorphous and deagglomerated morphology of Mo–WO3. Furthermore, the EC activity of Mo–WO3 film does not require an external power source as the film is powered by an integrated quantum dot-sensitized solar cell (QDSSCs). The open circuit voltage of 0.62 V, resulting from the QDSSCs power source, successfully facilitates the switching operation of the Mo–WO3 EC film.

Ag and Cu2O bimetal co-modified TiO2 nanotubes with enhanced photocatalytic performance

Titanium dioxide nanotubes (TiO2 NTs) have been widely used in photocatalytic systems due to their stable properties and low cost. In this study, TiO2 NTs were modified with Ag and Cu2O by electrochemical co-deposition. The results revealed that the co-deposition of Ag and Cu2O highly improved the photocatalytic performance of TiO2 NTs. The maximum photoelectric conversion efficiency was 22.65%, which was nearly three times higher than that of pristine TiO2 NTs. The S-scheme heterojunction mechanism was proposed to explain the electron-transfer mechanism of Ag-Cu2O-TiO2 NT.

Influences of Al particles and current density on structural, mechanical and anti-corrosion properties of electrodeposited Ni–Co/Al composite coatings

Ni–Co/Al composite coatings have been synthesized via electrochemical co-deposition routes. The effects of Al particle concentration upon the co-electrodeposition and performance of Ni–Co/Al composite coatings have been evaluated. The prepared coatings present compact and flat surfaces, displaying nodular-like morphology that consists of grain clusters. The grain sizes of the coatings were refined from 30 nm to 25 nm when Al particles were added but enlarged from 27 nm to 38 nm with the increase of current density from 2 to 8 A dm−2. The mean value of Ra of the surface prepared at 2 A dm−2 and 6 A dm−2 was 191 nm and 302 nm, respectively, indicating large current density promoted the rougher surface. The Ni–Co/Al obtained at 2 A dm−2 and 20 g L−1 Al particles contains about 13.77 wt% Al. Microhardness was improved as Al particles increased in the Ni–Co matrix, but coefficients of friction (COF) decreased in the presence of Al particles. As Al particle concentration increased, the corrosion resistance first enhanced and then declined when Al surpassed 40 g L−1. Due to the competition of reduction deposition between Ni and Co ions in electrolytes, it was found that Co content increased and Ni content decreased for Ni–Co/Al deposits. The Ni–Co/Al composite coating electrodeposited at 2–4 A dm−2 with 20–40 g L−1 Al particles exhibited the best mechanical and anti-corrosion performance.

Cr-Co Oxide Coatings Resistant to Corrosion, Electrodeposited on 304 SS Using an Ethylene Glycol-Water Solvent

The electrochemical co-deposition of Cr-Co oxide coatings at room temperature on 304 stainless steel (SS) was studied using an electrolyte composed of a mixture of ethylene glycol (EG), hydrated metal chloride salts (MCln∙YH2O), and water as a secondary hydrogen donor (HBD). Metallic Cu and Ni undercoats were applied to improve the adhesion of a posterior Cr-Co metallic and oxide layer. The electroactive events that took place during both electrodeposition processes were studied using cyclic voltammetry (CV) and chronoamperometry. The microstructure and composition of the surface layers were studied using scanning electron microscopy (SEM/EDS), X-ray diffraction (XRD) and cross-sectional elemental mapping via transmission electron microscopy (TEM). The surface of steel with the Cr-Co:EG-H2O coating showed greater resistance to pitting corrosion (123.93 mV) compared to untreated stainless steel (62.3 mV). This sample showed a large hystere-sis area, which is associated with high resistance to pitting corrosion by the occurrence of a re-passivation of the sample at a Erep value of 24.31 mV. After the cyclic potentiodynamic polariza-tion (CPP) test, the lowest specific mass loss (0.001 mg/cm2) was achieved for the AISI 304 SS sample coated using EG-water solvents (Cr-Co:EG-H2O), while the untreated AISI 304 SS reached a higher specific mass loss (0.01 mg/cm2). The Electrochemical Impedance Spectroscopy (EIS) tests showed that the uniform corrosion resistance varied significantly from the untreated AISI 304 SS (35 kΩ) to the coated sample (57 kΩ), which is attributed to the protection provided by the chromium and cobalt oxides coating. The best corrosion resistance achieved was correlated with a superhydrophobic character (with a contact angle of 158.41°) of the Cr-Co coatings. This was in turn a consequence of a needle-like morphology characteristic of these oxides.

Влияние структуры пленок Co – Ni – Fe, полученных электрохимическим осаждением, на магнитные свойства

An analysis of the crystal structure and composition of Co – Ni – Fe films was carried out and the influence of the deposition rate on the conversion of a weak magnetic field into a magnetic induction dB/dH was established. The presence of oxygen on the surface of the films indicates the porosity of the structure of the Co – Ni – Fe films, which is confirmed by the roughness of the morphology. Electrochemical deposition from a chloride electrolyte showed the possibility of controlling the magnetic properties of films while improving the deposition method. Chloride electrolyte with filtration, additives of boric acid, saccharin and hydrochloric acid at a ratio of concentrations CCo:CNi:CFe = 1: 1: 1 with a temperature of 70 °C provides reproducible electrochemical deposition of Co – Ni – Fe films with low mechanical stresses, with a uniform structure and with a high gain of a weak magnetic field in magnetic induction.

Self-Repairing Ability of Hybrid Cobalt Hydroxide Nanosheets As Oxygen Evolution Catalysts in Alkaline Electrolytes

Introduction Water electrolysis is a key technology to produce H2 from renewable energy. Because proton exchange membrane water electrolyzers (PEMWE) require noble metals as catalysts, alkaline-type electrolyzers, such as alkaline water electrolyzers (AWE) and anion exchange membrane water electrolysis (AEMWE), have attracted much attention for the use of nonnoble-metal-based catalysts. One of the most important issues of AWE is the degradation of catalysts due to generation of reverse current upon shutdown and power fluctuation. Reverse current hardly generates in AEMWE in principle; however, it possibly generates if an electrolyte is supplied instead of pure water.We have previously reported the self-repairing anode catalysts for AWE [1, 2]. A hybrid cobalt hydroxide nanosheet (denoted as Co-ns, Figure 1a), a Brucite-type cobalt hydroxide modified with tripodal ligands (tris(hydroxymethyl)aminomethane), was dispersed in an alkaline electrolyte. Co-ns is deposited on the anode during the electrolysis at 800 mA/cm2 to form a catalyst layer. After the degradation of the catalyst by potential cycling, Co-ns is deposited to retain the catalytic activity. To develop catalysts with higher activity, durability, and repairing ability, the understanding of the electrochemical deposition of Co-ns is quite important. Here, we demonstrate the mechanism of the electrochemical deposition of Co-ns.ExperimentalCo-ns was synthesized according to our previous report [1]. The Co-ns was dispersed in 1 M KOH electrolyte at varied concentrations of Co-ns. Ni electrodes were used as both working and counter electrodes. Reversible hydrogen electrode (RHE) was used as a reference. Constant current electrolysis at 800 mA/cm2 was applied for 30 min, followed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) to evaluate the oxygen evolution reaction (OER) activity and the amount of deposited Co. These processes ware repeated for several times to characterize the deposition behaviors. Similar experiments were performed, using Co(OH)2 or CoOOH instead of Co-ns.Results and DiscussionCo-ns was transformed into CoOOH by the decomposition of the tripodal ligand. The deposited amount of Co was evaluated by CV, in which the charge of the cathodic currents at 0.8–1.6 V vs. RHE (denoted as Q c) was proportional to the amount of Co measured by ICP-AES. Figure 1b shows the plots of Q c vs. duration of electrolysis. The amounts of deposited CoOOH depended on the concentration of Co-ns. The deposition rates (slope of the curves) gradually decreased along with the progress of the catalyst deposition. During the electrolysis, the electrode potential decreased because of the increased OER activity due to the catalyst deposition. Assuming that the deposition of CoOOH is a pseudo first-order reaction, its rate constant was calculated by dividing the deposition rate by the concentration of Co-ns. The rate constants are linearly correlated with the electrode potential (Figure 1c); thus, the deposition was confirmed to be an electrochemical process. The present results mean that the electrochemical deposition of CoOOH is accelerated when the electrode potential increases due to the degradation of catalysts. Therefore, the self-repairing process is automatically controlled by the condition of the electrode.The electrochemical deposition proceeds with Co(OH)2, whereas CoOOH hardly deposited at the same conditions, indicating that the oxidation of Co2+ to Co3+ is an essential step of the electrochemical deposition. The electrochemical deposition of Co(OH)2 was stopped after 60 min of electrolysis because of the autooxidation of Co(OH)2 by dissolving O2. It was shown that Co-ns is stable in an electrolyte saturated with O2 probably because the organic modification suppresses the autooxidation. Thus, it is shown that the organic modification of cobalt hydroxide is crucial to retain the self-repairing ability in an electrolyzer.ConclusionIn conclusion, the potential dependence of the rate constant and the essential step of electrochemical deposition of Co-ns were elucidated through systematic studies using Co-ns and related metal hydroxide catalysts. These findings lead to the design of self-repairing electrocatalysts with high activity, long lifetime, and high self-repairing ability using organic functionalization.Acknowledgement This work was supported by the JSPS KAKENHI (grant number 20H02821). Part of this study uses outcomes of the development of fundamental technology for the advancement of water electrolysis hydrogen production in the advancement of hydrogen technologies and utilization projects (grant number JPNP14021) commissioned by the New Energy and Industrial Technology Development Organization (NEDO) in Japan.

Visible-Light-Enhanced Hydrogen Evolution through Anodic Furfural Electro-Oxidation Using Nickel Atomically Dispersed Copper Nanoparticles.

A novel copper nanoparticle variant, denoted as Cu98Ni2 NPs, which incorporate Ni atoms in an atomically dispersed manner, has been successfully synthesized via a straightforward one-pot electrochemical codeposition process. These nanoparticles were subsequently employed as an anode to facilitate the oxidation of furfural, leading to the production of hydrogen gas. Voltammetric measurements revealed that the inclusion of trace amounts of Ni atoms in the nanoparticles resulted in a pronounced synergistic electronic effect between Cu and Ni. Consequently, a 43% increase in current density at 0.1 V was observed in comparison to pure Cu NPs. Importantly, when the Cu98Ni2 NPs were irradiated with visible light, a remarkable current density enhancement factor of 505% at 0.1 V was achieved relative to that of pure Cu NPs in the absence of light. This enhancement can be attributed to localized surface plasmon resonance induced by visible light, which triggers photothermal and photoelectric effects. These effects collectively contribute to the significant overall improvement in the electrocatalytic oxidation of furfural, leading to enhanced hydrogen evolution.

FORMATION AND PROPERTIES OF BIMETALLIC ELECTROCATALYSTS BASED ON AMINOPHENYL PORPHYRIN METAL COMPLEXES

In this work the bimetallic composites formation via electrochemical co-deposition of Fe(III)Cl-5,10,15,20-tetrakis(4-aminophenyl)porphyrin and Mn(III)Cl-5,10,15,20-tetrakis(4- aminophenyl)porphyrin has been studied. The composites were obtained by superoxide-assisted electrochemical deposition from mixed DMSO solutions with equal concentrations of porphyrins. Spectral analysis of the obtained composites has shown their enrichment with Mn-complexes of porphyrin. Comparative analysis of morphology and electro active surface area, as well as the responses in oxygen electro reduction process on their surfaces has been carried out for individual porphyrins and composites films. A higher catalytic activity has been demonstrated for the films of the bimetallic composites as compared to those of the individual metal complexes.

Electrochemical preparation and alkaline water splitting activity of ternary Co–Fe–Mo non-crystalline coatings

The influence of Na2MoO4 concentration on the electrochemical deposition of Co–Fe and Co–Fe–Mo alloy coatings from slightly acidic citrate baths and their electrocatalytic performance for alkaline water electrolysis in 1 M NaOH solution have been examined. The chemical composition and the evolution of the crystallographic structure have been analyzed by X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), and scanning electron microscope with energy dispersive spectroscopy (SEM-EDS) measurements. Increasing concentration of Mo in the alloy led to gradual amorphization of the crystalline structure. Electrochemical studies revealed that the cathodic Tafel slope reduced to 69 mV/dec for Co–Fe–Mo alloys. Furthermore, a low overpotential value of −121 mV was observed from polarization studies, which confirmed a good catalytic activity for the alkaline water splitting process.

Fabrication of ternary Cu-Sb-Te thin films by electrochemical co-deposition strategy at one-stage process

Fabrication of ternary Cu-Sb-Te thin films by electrochemical co-deposition strategy at one-stage process

Study on diffusion kinetics of chromium and nickel electrochemical co-deposition in a NaCl–KCl–NaF–Cr2O3–NiO molten salt

Abstract The process of preparing surface composite by molten salt co-deposition is the result of the mass transfer of active particles in molten salt, electrochemical reduction, and solid diffusion. In this study, we prepared Cr–Ni alloy/low-carbon steel surface composites in NaCl, KCl, NaF, Cr2O3, and NiO melt salt system successfully, and analyzed the entire diffusion dynamics process, aiming to find out the limiting links and provide ideas for further improving the preparation efficiency. The results show that chromium and nickel ions are simultaneously reduced on the cathode surface through two and one steps, respectively. And an alloy layer with Fe content of 64.52 wt%, Ni content of 28.96 wt%, and Cr content of 6.52 wt% is formed on the surface of low-carbon steel substrate. The average diffusion coefficients of chromium and nickel atoms in the surface composites are 1.16 × 10−14 and 1.44 × 10−14 m2·s−1. The mass transfer process in molten salt is the limiting link in the whole preparation process.

An ultrasensitive electrochemical sensor for detecting porcine epidemic diarrhea virus based on a Prussian blue-reduced graphene oxide modified glassy carbon electrode

This study developed a novel, ultrasensitive sandwich-type electrochemical immunosensor for detecting the porcine epidemic diarrhea virus (PEDV). By electrochemical co-deposition of graphene and Prussian blue, a Prussian blue-reduced graphene oxide-modified glassy carbon electrode was made, further modified with PEDV-monoclonal antibodies (mAbs) to create a new PEDV immunosensor using the double antibody sandwich technique. The electrochemical characteristics of several modified electrodes were investigated using cyclic voltammetry (CV). We optimized the pH levels and scan rate. Additionally, we examined specificity, reproducibility, repeatability, accuracy, and stability. The study indicates that the immunosensor has good performance in the concentration range of 1 × 101.88 to 1 × 105.38 TCID50/mL of PEDV, with a detection limit of 1 × 101.93 TCID50/mL at a signal-to-noise ratio of 3σ. The composite membranes produced via co-deposition of graphene and Prussian blue effectively increased electron transport to the glassy carbon electrode, boosted response signals, and increased the sensitivity, specificity, and stability of the immunosensor. The immunosensor could accurately detect PEDV, with results comparable to real-time quantitative PCR. This technique was applied to PEDV detection and served as a model for developing additional immunosensors for detecting hazardous chemicals and pathogenic microbes.

Congruent Electrochemical Deposition of Co–Ni–Fe Films

Congruent Electrochemical Deposition of Co–Ni–Fe Films

Electrochemical Codeposition of Sm and Co in a Dicyanamide Ionic Liquid

Electrochemical Codeposition of Sm and Co in a Dicyanamide Ionic Liquid

Electrochemical co-deposition of cobalt and graphene, produced from recycled polypropylene, on TiO2 nanotube as a new catalyst for photoelectrochemical water splitting

In this study, to improve the photoelectrochemical properties of TiO2 nanotubes (TNT), the hybrid TNT-graphene-Co(OH)2 was prepared using electrodeposition of graphene and cobalt salt. The employed graphene was obtained from the waste polypropylene using chemical vapor deposition method. The hybrid material showed high thermal stability and promising visible light absorption. Moreover, its XRD pattern and Raman spectrum are in accordance with the precursors. The photoelectrochemical performance of this hybrid material was investigated using linear sweep voltammetry, transient open circuit potential, and chronoamperometry. Because of the existence of graphene, the prepared hybrid material exhibited excellent photoelectrochemical properties and the results were more appropriate than those of TNT and cobalt deposited TNT. Among the various samples with different amounts of graphene, the sample with the highest graphene content showed the highest photoelectrochemical abilities. This improvement is mainly related to the visible-light harvesting ability of graphene and facile recombination of photogenerated electron-hole pairs due to the synergistic effect of the involved materials.

Co-deposited CuNi@MWCNTs nanocomposites for structural applications: tribo-mechanical and anti-corrosion performances

ABSTRACT In the present work, multi-walled carbon nanotube (MWCNT) nanofiller reinforced copper-nickel alloy (CuNi@MWCNTs) nanocomposites were synthesised by a modified electro-chemical co-deposition followed by compaction and sintering. During this method, CuNi@MWCNTs were co-deposited on a cathode tip at room temperature and collected from the electro-chemical bath in powdered form. Subsequently, the powdered nanocomposites were dried, compacted and sintered to prepare solid pellets. The influence of different amounts (25, 50 and 100 mg L−1) of MWCNT nanofillers in the deposition bath on microstructure, mechanical and anti-corrosion properties of CuNi@MWCNTs nanocomposites was investigated. The microhardness, compressive yield strength and friction coefficient of CuNi@MWCNTs (100 mg L−1) nanocomposites were enhanced by 45.7%, 37.2% and 55.1%, respectively, compared to that of pure CuNi alloy. In addition, the CuNi@MWCNTs nanocomposites obtained also exhibited improved anti-corrosion property in 3.5 wt.% NaCl solution at continuous agitation of 150 rpm and 27°C temperature. Based on the research outcomes, this approach for synthesising CuNi@MWCNTs nanocomposites may be proposed for scale-up industrial trials.

In:Ge/Cu@calcein polyhedral nanostructure conducted photoelectrochemical biosensor for detection of IFN-gamma

A novel photoelectrochemical (PEC) biosensor based on the In:Ge/Cu@calcein polyhedral nanostructure was fabricated for ultrasensitive determination of interferon (IFN)-gamma. The calcein dye could trigger Cu nano-octahedral to transform Cu nano-polyhedral structure and attach orderly to the its surfaces by electrochemical co-deposition, and facilitate photocurrent response dramatically enhancing by five-folds. The In:Ge/Cu@calcein demonstrates excellent PEC performance resulting from the synergistic sensitization of calcein and In:Ge/Cu nanostructure, as well as supplying rich carboxy groups to couple with other biomolecules for simply fabricating biosensor, which has a wide dynamic range (from 50 fg mL −1 to 1 ng mL −1 concentrations of IFN-gamma), and a lower detection limit of 24 fg mL −1 .