Electrodeposition Of Iron Research Articles

Iron-Reduced Graphene Oxide Core-Shell Micromotors Designed for Magnetic Guidance and Photothermal Therapy under Second Near-Infrared Light.

Core-shell micro/nanomotors have garnered significant interest in biomedicine owing to their versatile task-performing capabilities. However, their effectiveness for photothermal therapy (PTT) still faces challenges because of their poor tumor accumulation, lower light-to-heat conversion, and due to the limited penetration of near-infrared (NIR) light. In this study, we present a novel core-shell micromotor that combines magnetic and photothermal properties. It is synthesized via the template-assisted electrodeposition of iron (Fe) and reduced graphene oxide (rGO) on a microtubular pore-shaped membrane. The resulting Fe-rGO micromotor consists of a core of oval-shaped zero-valent iron nanoparticles with large magnetization. At the same time, the outer layer has a uniform reduced graphene oxide (rGO) topography. Combined, these Fe-rGO core-shell micromotors respond to magnetic forces and near-infrared (NIR) light (1064 nm), achieving a remarkable photothermal conversion efficiency of 78% at a concentration of 434 µg mL-1. They can also carry doxorubicin (DOX) and rapidly release it upon NIR irradiation. Additionally, preliminary results regarding the biocompatibility of these micromotors through in vitro tests on a 3D breast cancer model demonstrate low cytotoxicity and strong accumulation. These promising results suggest that such Fe-rGO core-shell micromotors could hold great potential for combined photothermal therapy.

Electrodeposition of iron from 1-ethyl-3-methylimidazolium trifluoromethanesulfonate and reverse microemulsions of Triton X-100.

Electrodeposition of iron (Fe) was investigated in three different media, namely a hydrophilic ionic liquid (IL), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, conventional reverse microemulsion (RME)/reverse micellar solution, and IL-based RME of a non-ionic surfactant, Triton X-100, with a view to electrodepositing iron with desired morphology. Electrochemical behaviour of Fe2+ was studied using cyclic voltammetric technique with a copper electrode as the working electrode. Electrochemical reduction of Fe2+ in all the studied media was found to be an electrochemically irreversible, diffusion-controlled process. Successful potentiostatic electrodeposition of metallic iron was performed in all the studied media on copper substrate using bulk electrolysis method. The obtained iron electrodeposits were characterized using a scanning electron microscope and an X-ray diffractometer. The controlled diffusion of Fe2+ towards electrode surface in all the media resulted in the formation of nanoparticles of iron, but compact layers of granular nanoparticles could be achieved from both the conventional and IL-based RME systems. The IL-based microemulsions synergistically combined the advantageous features of both the IL and RME and showed promise for tuning the size, shape, and morphology of the electrodeposited iron.

On the formation of dendritic iron from alkaline electrochemical reduction of iron oxide prepared for metal fuel applications

Low-temperature electrochemical reduction (electroreduction) of iron oxides is a promising alternative to the conventional methods for iron production due to its CO2-free operation and relatively low energy consumption. In this work, we demonstrate a novel approach for electrochemical iron production by promoting the formation of dendritic structures during iron electrodeposition, which facilitates the easy harvesting of deposits in powder form. Experiments were conducted using a single pair of parallel plate electrodes, immersed in a mixture of hematite (Fe2O3) powder and aqueous alkaline (NaOH) slurry. The effects of current density, Fe2O3 mass fraction, temperature, and powder size on current efficiency and deposit morphology are investigated. A large quantity of dendritic iron structures is observed when experiments are carried out without stirring and/or applying heat from a heating plate. This condition suggests temperature and (ion/species) concentration gradients in the system. The dendrites are mainly deposited on the cathode's sides, corners, and edges. Different deposits and dendritic structures (compact layer deposit, moss-like deposit, deposit with whisker-like dendrites, and deposit with crystal-like dendrites) are observed as operating conditions change. Overall, a cathodic deposition of metallic iron with a high Faradaic efficiency (≥90 %) is successfully accomplished. The present findings provide new insights into the production of electrolytic iron powder and its future use as a carbon neutral and sustainable fuel/energy carrier.

Morphological control of electrodeposited iron for fluctuating photovoltaic electrical energy

With the Paris Agreement, the installed capacity of green power, such as photovoltaic (PV) and wind power, is growing rapidly at a rate of more than 10 % per year. The practical application of these green electrical energies is limited by the relative lag in the scale of energy storage systems. In response to the pressure on energy storage systems, we explored the feasibility of supplying DC power directly from a PV plant to an industrial electrolyzer by comparing the electrodeposition behavior of Fe2+ in a sulfuric acid system from stabilized DC and fluctuating PV power sources. We found that the factor that damages the stable operation of an iron electrodeposition system the most is the presence of hydrogen evolution reactions, where the generation of hydrogen bubbles reduces the current efficiency of the electrodeposition system and, in severe cases, destroys the surface morphology of the deposited products, causing devastating damage to the system. On this basis, we designed a simple scheme that uses heterogeneous bubble nucleation instead of homogeneous bubble nucleation for rapid bubble expulsion from the cathode surface. Benefiting from the rapid transfer of bubbles, the current efficiency of the electrodeposited iron system increases by 1.25%–10 % at different current densities, and the maximum roughness decreases by 129–2,396 nm, which considerably improves the stability of the electrodeposited iron system for PV power. This work provides useful experimental support for the transformation of the traditional steel smelting industry, which is characterized by high carbon emission and energy consumption, into an environmentally friendly industry.

Enhanced electrocatalytic efficiencies for water electrolysis and para-nitrophenol hydrogenation by self-supported nickel cobalt phosphide-nickel iron layered double hydroxide p-n junction

Charge redistribution across heterointerfaces is an important tactic to enhance the catalytic activities and bifunctionality of hybrid catalysts, especially for green hydrogen production from water electrolysis and harmless electrocatalytic valorization of organics. Herein, a self-supported p-n junction catalytic electrode was constructed by tandem electrodeposition of nickel cobalt phosphide (NiCoP) and nickel iron layered double hydroxide (NiFe LDH) onto Ni foam (NF) substrate, denoted as NiCoP@NiFe LDH/NF, to enhance the electrocatalytic capabilities for water electrolysis and hydrogenation of an organic, para-nitrophenol (4-NP). Benefitting from the charge redistribution across the p-n junction, high electrocatalytic efficiencies for oxygen evolution reaction (OER, overpotential of 388 mV at 100 mA cm−2) and hydrogen evolution reaction (HER, overpotential of 132 mV at 10 mA cm−2) could be achieved concurrently by the NiCoP@NiFe LDH/NF electrode, and both overpotentials were located within the mainstream levels in this domain. The bifunctional catalytic features enabled a full water electrolysis response of 10 mA cm−2 at 1.61 V. In addition, the p-n junction electrode catalyzed the hydrogenation of 4-NP at a conversion of 100%, para-aminophenol (4-AP) selectivity of 90% and faradaic efficiency (FE) of 88% at −0.18 V. The current work offers a feasible strategy for fulfilling electrochemical H2 production and hydrogenation valorization of 4-NP pollutant by constructing a self-supported p-n junction catalytic electrode.

Features of the Process of Galvanic Deposition of Metals into the Ion Track Membranes’ Pores

The paper considers some aspects of obtaining metal nanowires by matrix synthesis based on track membranes. In the first part of the paper, the main ideas of the method are considered and a review of the literature on the synthesis of nanowires of various types of single component (from one metal) and multicomponent—from two or more metals is given. In the second part of the review, variants of obtaining homogeneous structures of so-called alloyed nanowires and heterogeneous structures of so-called layered nanowires are considered. Several specific features of the electrodeposition method during the process in a limited volume of membrane pores are considered. In the second part of the work, the experimental results obtained by the authors in the study of electrodeposition of nanowires made of an iron–nickel alloy are considered. The so-called abnormal electrodeposition of iron was detected. The dependence of the integral element composition of the obtained nanowires on the pore diameter and on the growth voltage is discussed. Data on the nature of the distribution of elements along the length of nanowires are obtained. The unevenness of the composition is determined by the conditions of production (in particular, the different diffusion mobility of ions in narrow pore channels) and also depends on the voltage and diameter of the pore channels. Based on the X-ray diffraction data, the type of lattice (hcc) is determined and the nature of the change in the lattice parameter is shown, presumably associated with the difference in the ionic radii of metals.

Electrochemical Reduction of Iron Oxide - Produced from Iron Combustion - for the Valorization of Iron Fuel Cycle

Iron is a prospective candidate for energy carriers in the energy transition era with high energy density. In this concept, energy is released by the combustion of iron powder whilst the solid product - iron oxide - can be collected and reduced back to metallic iron, forming a recyclable iron fuel cycle. The electrochemical technique is considered to be a suitable reduction method as it has attractive aspects including low electric energy consumption, low temperature, direct usage of renewable energy, and a short process chain. In this study, the performance of iron electrodeposition is investigated using an electrolysis cell containing a suspension of micron-sized combusted iron powder in aqueous NaOH (50%wt, 18 M) at a temperature of 110°C. The parallel plate electrolyzer used in these experiments consists of a stainless-steel plate (cathode) and a nickel gauze (anode). The effects imposed by varying current density, iron oxide composition, and iron oxide particle diameter on Faradaic efficiency and reduced iron yield are evaluated. Additional experiments using a rotating disc electrode (RDE) are also conducted to determine the system's diffusion coefficient under different operating conditions. Generally, cathodic deposition of metallic iron is successfully achieved and the morphology of the deposited iron depends on the operation conditions including the current density and heterogeneity of the flow system. The obtained results open new perspectives for efficient and cost-effective iron production/regeneration. Figure 1

Study of the damping behaviour in samples consisting of iron electro-deposited on copper in an ionic liquid

Copper-iron alloys were produced at room temperature by means of electrodeposition of iron on a copper substrate in an ionic liquid (1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate [Py 1,4 ]TfO). Samples with different electrodeposition times were studied using mechanical spectroscopy, scanning electron microscopy, light microscopy and magnetic loops techniques. Independent of the electrodeposition time the electrodeposition process leads to the promotion of a thin layer of iron onto the copper surface without iron diffusion into the substrate. The damping spectra for electrosposited samples in the as-electrodeposited state show the characteristic low and intermediate grain boundary damping peaks from copper as well as the solvent grain boundary damping peak from the electrodeposited iron. Thermal annealing at temperatures near 973 K leads to the appearance of Fe particles at the interface between the copper and iron (Cu + α-Fe phase) leading to a new damping peak at around 680 K whose driving force is the diffusion of copper atoms around the second phase particles. • Iron-copper alloys produced by electrodeposition in an ionic liquid at room temperature. • Grain boundaries relaxation for the copper and iron in bi-layered alloys. • Damping peak related to the diffusion of copper atoms around the (alpha-Fe) particles.

Electrodeposited Fe on Cu foam as advanced fenton reagent for catalytic mineralization of methyl orange.

In many countries, the textile industry remains the major contributor to environmental pollution. Untreated textile dyes discharged into water negatively impact the performance of aquatic organisms and may cause a variety of serious problems to their predators. Effective wastewater treatment is a key to reducing environmental and human health risks. In this work, the Fe/Cu catalysts were used in heterogeneous Fenton’s reaction for the degradation of high concentrations of methyl orange (model azo dye) in aqueous solutions. For the first time, the catalysts were prepared onto commercial copper foams by potentiostatic electrodeposition of iron using an environmentally friendly electrolyte. The influence of electrodeposition conditions, H2O2 concentration, dye concentration and temperature on the model dye degradation was investigated. It was revealed that both the surface area and the catalyst loading play the major role in the effective dye degradation. The experimental results involving spectrophotometric measurements coupled with total carbon and nitrogen quantification suggest that a solution containing up to 100 mg/L of methyl orange can be successfully decolorized within 90 s at 50°C using porous Fe/Cu catalyst in the presence of hydrogen peroxide that largely surpasses the current state-of-the-art performance. Already within the first 10°min, ∼ 30% of total methyl orange concentration is fully mineralized. The described process represents a cost-efficient and environmentally friendly way to treat azo dyes in aqueous solutions.

The Influence of the Substrate and External Magnetic Field Orientation on FeNi Film Growth

The magnetic field-assisted electrodeposition of iron–nickel thin films on different substrates (aluminum, silver, and brass) was investigated. The process was performed galvanostatically in a sulfate solution. The same chemical and electrical conditions were applied for each sample growth, but the time restrictions and the external magnetic field orientation were changeable. The obtained results show a variation of surface morphology and composition dependence on the selected surfaces as a consequence of the presence and orientation of the external magnetic field. We discussed that the FeNi crystal structure depends on the film thickness. The results show the reduction of the film thickness after the external magnetic field application—a decrease of deposition rate.The FeNi alloy’s morphology, composition, and magnetic properties were investigated by scanning electron microscopy (SEM), X-ray diffraction, energy dispersive X-ray spectroscopy (EDX), and Mössbauer spectroscopy (MS).

Initial stages of electrocrystallization of nickel, iron and nickel-iron alloy on a glassy carbon electrode in an electrolyte based on a eutectic mixture of choline chloride and ethylene glycol

The kinetics and mechanism of the initial stages of electrocrystallization of nickel, iron and nickel-iron alloy were characterized for the process of electrolytic deposition from a solution based on deep eutectic solvent ethaline (liquid mixture containing choline chloride and ethylene glycol at a molar ratio of 1:2, respectively). The theoretical model developed by Scharifker and Hills was used to interpret the obtained experimental data. It was shown that the electrodeposition of nickel and iron obeys the patterns of three-dimensional instantaneous and progressive nucleation, respectively. It was concluded that the formation of iron nuclei occurs at a significantly lower rate than in the case of nickel. The kinetics of the initial stages of Ni–Fe alloy deposition obeys the mechanism of instantaneous nucleation. Thus, in the case of electrolytic deposition from ethaline-based solutions on a glassy carbon electrode, nickel imposes on iron not only its own region of electrode potentials where alloy deposition occurs, but also the type of mechanism of nucleation in the course of codeposition.

Alternating Current for the Selective Electrodeposition of Cadmium, Iron, and Chromium Method Development for Simulated Industrial Wastewater Sludge

A preliminary study of the selective electrodeposition of Cadmium (Cd), Iron (Fe), and Chromium (Cr) from industrial wastewater sludge using alternating current. There are no large-scale methods for recovering the metals contained in the sludge resulting from industrial wastewater treatment. This study expanded on a method for using Alternating Current (AC) and a Graphene-Oxide-Modified Carbon Felt Electrode (CF-GO) by using a larger volume than previously used in literature and optimizing AC settings for the selected metals. Cd concentration in solution was reduced by 5-10% over five hours using an AC setting of 4 MHz, 2 Vpp, and -5 VOffset. Fe had five AC settings that had regression line slopes less than -4 ppm/ hr, and Cr had one AC setting with regression line slope less than -4 ppm/hr. As the Cr AC setting of 1 Hz, 1 Vpp, and -8 VOffset also was efficient for the electrodeposition of Fe, the Fe would need to be removed from solution before Cr. Future work outlined includes further AC optimization, additional metals also found in industrial wastewater sludge, optimization of the order of metals electrodeposited, and testing the method on industrial wastewater sludge.

Electrodeposition of Ni–Fe alloy from solutions based on deep eutectic solvent ethaline

The kinetics of сodeposition of nickel and iron in an electrolyte based on a deep eutectic solvent (ethaline) was studied by voltammetry method. It was established that the partial voltammograms of iron ions reduction during alloy electrodeposition correspond to the region of electrode potentials, which is more than 100 mV positive in comparison with the electrodeposition potentials of pure iron. It was shown that the acceleration of iron ion electroreduction is associated with the gain in energy due to the alloy formation and a decrease in the overvoltage of iron electrodeposition during alloying. The change in the kinetics of iron electrodeposition can be explained by both a change in the mechanism of its electrodeposition in conjunction with nickel and a change in the state of the electrode surface in the potential region of the alloy formation. Comparison between the ratio of the content of the alloy components in the metal and the corresponding ions in the electrolyte showed that nickel and iron electrodeposit into the alloy in quantities that are proportional to their content in the electrolyte. Thus, electrodeposition of nickel-iron alloy from ethaline with a water content of up to 3% occurs by the so-called normal mechanism.

Electrochemical study of iron deposit in acid media for its recovery from spent pickling baths regeneration

• Fundamental study of iron electro-deposit from a model pickling bath carried out. • The effect of Fe 2+ concentration on electrochemical iron deposition was analyzed. • Tafel analysis showed redissolution of metallic Fe even at cathodic potentials. • Rotating disk electrode studies evidenced intermediate kinetics for the Fe deposit. • For Fe reduction electrolysis tests, the removal was until t = 400 s. Electrochemical technologies for the regeneration of spent pickling baths are feasible since they allow simultaneous metal deposition and acid production in the same process unit. In this work, the effect of Fe 2+ concentrations on the electrochemical iron deposition from aqueous model sulfate electrolytes (representing spent pickling baths) is analyzed by voltammetry switching potentials, Tafel analysis, and spectroelectrochemistry studies. The research showed that the electrodeposition rate and potential decreased as Fe 2+ concentration increased according to cyclic voltammetry tests. Moreover, at higher Fe 2+ concentrations, a decrease in the hydrogen evolution reaction was observed. Also, chemical Fe dissolution is present at all concentrations studied, due to the high corrosion rate of iron at the low pH of the model bath as was showed by voltammetry and Tafel plots analysis. Thermodynamic diagrams and electrochemical tests coupled to UV–VIS spectroelectrochemical analysis demonstrated the presence of iron sulfate complexes that are involved in the main electrochemical reaction.

Carbon dioxide conversion to C1 - C2 compounds in a microbial electrosynthesis cell with in situ electrodeposition of nickel and iron

This study demonstrates the continuous conversion of CO2 to methane, acetate, and ethanol in a Microbial Electrosynthesis Cell (MESC) with a carbon felt biocathode. The MESC was inoculated with a mixed anaerobic microbial consortium and operated at a mesophilic temperature of 30 °C. In situ deposition of Ni and Fe was achieved by introducing 0.2 g L−1 of NiSO4 or FeSO4, respectively, into the cathode compartment influent stream. In response, a considerable improvement in MESC performance was observed with a current density of 6.4 mA cm−2 (per separator area) and a CH4 production of 0.83 L (LR d)−1 (R = cathode volume). Once Ni and Fe were removed from the influent solution, the performance remained unchanged. Electron dispersive spectroscopy confirmed Ni and Fe electrodeposition. A shift from CH4 to acetate and ethanol production with concentrations reaching 5 and 8 g L−1, respectively, was observed upon increasing the cathode compartment pH to 8.5–9.0. 16S rRNA gene sequencing showed significant changes in the bacterial population at the cathode with Clostridia representing almost two-thirds of the population. Methanosaeta, Methanobrevibacter, and Methanobacterium species dominated the archaeal community.

Electrodeposition and Growth of Iron from an Ethylene Glycol Solution

The electrochemical reduction of iron (III) ions into zero-valent iron from a solution of ethylene glycol was accomplished. The kinetics and mechanism of the electroreduction process were investigated by cyclic and linear polarization techniques. The influence of temperature, potential sweep rate, and concentration of iron (III) ions on the electroreduction process was also studied. The observed values of effective activation energy revealed that the investigated electroreduction process is accompanied by mixed kinetics control. Moreover, the results of SEM and X-ray diffraction analysis confirmed the deposition of thin Fe films under the optimized conditions.

Electroplating of iron and its alloys

Analytical review of information on electrodeposition of iron and its alloys from aqueous solutions is carried out. Processes of electroplating of iron and its alloys from aqueous solutions and the principal fields of application of these galvanic coatings are discussed. The principal technological advantages of using iron coatings in the reconditioning of steel parts are considered. Compositions of electrolytes and conditions for plating of iron coatings are provided. Technological parameters of electroplating of iron from industrial electrolytes are considered. Data are presented on the effect of some organic additives on the iron plating process. The effect of the concentration of Fe3+ ions in iron plating electrolytes on electroplating of iron coatings and their physic-mechanical properties is discussed. The data are presented on physic-mechanical properties of iron coatings obtained in different electrolysis modes. Nonsteady-state electrolysis modes are discussed that are used in industry for application of iron coatings. The effect of coating plating conditions on their mechanical properties is studied. Technological parameters of electroplating of iron alloys are considered. Co-deposition of iron with nickel, chromium, titanium, phosphorus, molybdenum, vanadium and tungsten is described. Data are provided on compositions of electrolytes and conditions of electroplating of these alloys. Main fields of application of electroplated iron alloys are discussed. Information is provided.

Intensification of the recovery of hydraulic equipment parts by iron in the electrolyte flow

The technology of bath-free ironing of parts in an electrolyte flow with simultaneous hydromechanical activation of the growing surface is proposed. Its advantages over the traditional type of coating are introduced. The structure, some physicomechanical and operational properties of iron coatings were studied depending on the electrolysis regimes and the composition of electrolytes. The possibility of high-speed electrodeposition of iron with a wide range of physical and mechanical properties is shown. There were shown the electrolysis modes, which make it possible to obtain high-quality strong-adhered pure-iron coatings with a wear resistance several times higher than hardened alloy steels and a precipitation growth rate tens of times higher than with traditional ironing. A typical technological process of parts ironing was developed. It was tested on the example of restoration of hydraulic valve spools of agricultural machinery. The design of an installation and an electrochemical cell for ironing the valve hydraulic distributors, providing optimal hydrodynamic conditions when applying coatings to worn surfaces, was proposed. Recommendations for the post-electrolysis treatment of restored parts by iron are given. Bench and field tests of hydraulic valves with remanufactured valves were carried out. They confirmed the results of laboratory studies, and showed that no malfunctions were identified during the operation period. Technical and economic calculations have shown the high efficiency of the proposed technology in comparison with traditional ironing. The introduction of the technology in production will reduce the production area and the time spent on restoring parts by increasing the productivity of the iron process and reducing the number of operations, reducing the cost of materials for preparing electrolytes by reducing the operation of anodic treatment and washing, and increasing the reliability of the technology by improving its structural scheme.

Eutectic Mixture of Iron(III) Chloride and Acetamide — Physicochemical Properties, Chemical Speciation, and Electrodeposition of Iron

The electrodeposition of iron alloys is a significant research topic, owing to the potential applications such as corrosion/wear-resistant coatings1, magnetic thin films2, and catalyst electrodes3. Although aqueous electrolytes have been mostly used for electrodeposition, vigorous hydrogen evolution on the cathode can lead to hydrogen embrittlement and precipitation of metal hydroxides2. In addition, less noble elements such as aluminum and silicon cannot be co-deposited from aqueous electrolytes due to the limited electrochemical window.To overcome the limitations of aqueous solutions, non-aqueous systems such as molten salts and ionic liquids have gained significant research attention. The electrochemical behaviour of iron complexes in imidazolium- and pyrrolidinium-based ionic liquids, and electrodeposition of metallic Fe was demonstrated in some liquids4,5. Many ionic liquids are, however, not viable on a practical scale.In this study, we explored an alternative electrolyte to ionic liquids for electrodeposition of iron. A mixture of ferric chloride and acetamide is shown to give a liquid at ambient temperature. This eutectic mixture has a higher conductivity than comparable eutectics formed from either aluminium or zinc chloride. Ferric chloride disproportionates to form both anionic and cationic iron species identified using spectroscopic methods. The electrodeposition of dense metallic iron film was demonstrated. References N. Tsyntsaru et al., Surf. Eng. Appl. Electrochem., 48, 491–520 (2013)G. Panzeri et al., Electrochim. Acta, 271, 576–581 (2018)N.-C. Lo et al., J. Electrochem. Soc., 163, D9–D16 (2016).P. Giridhar, B. Weidenfeller, S. Z. El Abedin, and F. Endres, ChemPhysChem, 15, 3515–3522 (2014).Y. Zhu, Y. Katayama, and T. Miura, J. Electrochem. Soc., 159, D699–D704 (2012).

Effect of Magnetic Fields on the Behavior of Iron Electrodeposition

Effect of Magnetic Fields on the Behavior of Iron Electrodeposition