Fe Plate Research Articles

Roughness-Mediated SI-Fe0CRP for Polymer Brush Engineering toward Superior Drag Reduction.

Surface-initiated iron(0)-mediated controlled radical polymerization (SI-Fe0CRP) with low toxicity and excellent biocompatibility is promising for the fabrication of biofunctional polymer coatings. However, the development of Fe(0)-based catalysts remains limited by the lower dissociation activity of the Fe(0) surface in comparison to Cu(0). Here, we found that, by simply polishing the Fe(0) plate surface with sandpaper, the poly(methacryloyloxy)ethyl trimethylammonium chloride brush growth rate has been increased significantly to 3.3 from 0.14 nm min-1 of the pristine Fe(0) plate. The excellent controllability of roughness-mediated SI-Fe0CRP can be demonstrated by customizing multicompartment brushes and triblock brushes. Furthermore, we found that the resulting polymer brush coatings exhibit remarkably low water adhesion (0.097 mN) and an outstanding drag reduction rate of 52% in water. This work provides a promising strategy for regulating the grafting rate of polymer brushes via SI-Fe0CRP for biocompatible marine drag reduction coatings.

Theoretical prediction of texture requirements for improving the intrinsic cleavage crack resistance of BCC Fe

Based on the classical Rice model of crack tip dislocation emission, the present article provides a theoretical prediction of suitable grain orientations (texture components) in a rolled polycrystalline BCC Fe plate which can improve the overall resistance to cleavage crack propagation. Besides, the beneficial effect of alloying additions on further improvement in the intrinsic crack resistance of the steel is also discussed pertaining to the role of unstable stacking fault energy.

Hybrid-ion strategy enables ultra-long life aqueous iron-organic batteries

Among aqueous batteries, the research on the battery employing metal as the anode is still mainly focused on the aqueous zinc-ion battery. Compared with zinc, iron has better stability for reversible deposition, lower cost, and higher specific capacity, which is suitable for aqueous batteries. In this study, an aqueous iron-organic battery is constructed by employing polyaniline as the cathode, Fe plate as the anode, and Fe(CF3SO3)2 as the electrolyte, which demonstrates the hybrid storage mechanism of iron plating/stripping in the anode and transmission of CF3SO3− in the cathode. The polyaniline-Fe battery delivers a specific capacity of 105.8 mAh g−1 at a current density of 0.05 A g−1 and a stable cycle performance over 5,000 cycles with almost no capacity fading at a current density of 0.2 A g−1, which provides a new direction for the development of aqueous iron-ion batteries.

Mechanical and Corrosion Behavior of a Composite Gradient-Structured Cu-Fe Alloy

Immiscible Cu-Fe alloys exhibit poor corrosion resistance due to different corrosion potentials between the constituent phases, which limits their application. In this paper, a composite gradient-structured Cu-10 wt.%Fe plate was prepared via the ultrasonic surface rolling process (USRP). The microstructure evolution, mechanical properties and corrosion behavior were studied. The results demonstrate that USRP effectively enhances both the strength and corrosion resistance of the Cu-10Fe alloy. The improved strength is related to the combined effects of Hall–Petch strengthening, dislocation strengthening, and additional strengthening resulting from homogeneous deformation between the surface layer and the matrix. The enhanced corrosion resistance is primarily attributed to the refined microstructure of the surface layer after USRP, which facilitates the formation of a protective passivation film.

光沢剤を含むアルカリジンケート浴から電析したZn-Ni合金皮膜の耐食性

Zn–Ni alloys were electroplated on an Fe plate with thicknesses of 40 μm at 500 A·m−2 and 293 K in unagitated zincate solutions. The reaction product of epichlorohydrin and imidazole (IME) was added in the solution as a brightener at the concentration of 0-5 ml/dm−3. The corrosion resistance of the obtained Zn–Ni alloys films was investigated from the polarization curve in 3 mass% NaCl solution before and after the corrosion treatment (formation of corrosion products) in NaCl solution for 48 h. Before the corrosion treatment, the corrosion current density of plated films rarely changed regardless of addition of IME into the zincate solution because the reduction reaction of dissolved oxygen rarely changed. However, in films plated from the solution containing IME, the anode reaction was suppressed and the corrosion potential shifted to noble direction. The suppression of anode reaction with an addition of IME in plating solution is attributed to the increase in γ-phase in plated films. On the other hand, after the corrosion treatment, the morphology of Zn chloride hydroxide of corrosion product was uniformly formed on the surface with increasing the concentration of IME. The reduction reaction of dissolved oxygen was suppressed with increasing the concentration of IME, resulting in decrease in corrosion current density.

Growth of thick and long Fe oxide whiskers from Fe plate covered with SiO2 layer

The current study aims to fabricate thick and long Fe oxide whiskers using the process of stress-induced migration. Heating a polished Fe plate covered with a SiO2 layer at 750 °C causes Fe oxide whiskers to grow on the surface, whose diameter and length continue to increase along with increasing SiO2 layer thickness up to 53 nm and decrease for thicker layers. An optimal discharge resistance of the SiO2 layer was considered responsible for the formation of thick and long whiskers as it allows for a large accumulation of Fe below the SiO2 layer; discharge is observed at weak spots in cases where the driving force is the highest. Consequently, the Fe oxide whiskers of 0.57 μm diameter and 14.3 μm length were obtained after 2 h of heating.

Facile fabrication of flower-like γ-Fe2O3 @PPy from iron rust for high-performing asymmetric supercapacitors

Flower-like rust with porous structure can be obtained on the Fe plate by accelerated corrosion in the marine atmosphere. A core-shell structure of γ-Fe2O3 @PPy was developed through annealing and in situ chemical polymerization of pyrrole. The dehydroxylation after annealing enriches the inherent pore structure of rust. The conductive PPy layer with the capacitive properties were found to improve the stability of iron-based anodes while enhancing the charge storage performance. The rust-based composite exhibited superior capacitance performance over the original rust. By matching with a cathode from nickel-cobalt layered double hydroxide (NiCoLDH) based porous Ni network, the asymmetric device delivered a high volumetric energy density of 7.9 mWh cm–3 at a power density of 14.99 mW cm–3, and favorable cycle stability (capacitance retention of 90.1% after 8000 cycles). Most importantly, the energy storage mechanism of rust-based electrodes with flower-like structures was discussed in detail. The recycling and reuse of rust resources were successfully realized by the direct utilization of rusted steel as anode materials for supercapacitor applications.

Electrocoagulation technique for continuous industrial licorice processing wastewater treatment in a single reactor employing Fe-rod electrodes: Process modeling and optimization and operating cost analysis

Licorice processing industry produces a characteristic wastewater with a high chemical oxygen demand (COD), high turbidity, and intense color. Direct disposal of untreated licorice processing wastewater into water bodies can pose a serious risk to the human health and environment. The main objective of this study is to evaluate the performance of a novel laboratory scale continuous electrocoagulation (EC) reactor using iron (Fe) rod electrodes (anode and cathode) for treating a real licorice processing wastewater. Response surface methodology (RSM) was employed to investigate the effects of important parameters such as: current density (CD), electrolysis time, mixing intensity, and NaCl concentration for Fe rod electrodes on the removal efficiency of color, soluble COD (sCOD), and turbidity. In order to evaluate the effect of reactor design on the overall process performance, the results were compared with our previous study in which Fe plate electrodes were employed in an identical system. The process exhibited better performance in terms of turbidity removal for Fe rod electrodes with an average value of 59.35% in contrast to Fe plate electrodes (47.88%). Color and sCOD removal efficiencies of 94.6% and 90.1% were achieved, respectively for the EC system using Fe rod electrodes under optimum conditions: electrolysis time (71.8 min), CD (28 mA/cm2), mixing intensity (45 rpm). While in the EC reactor using Fe plate electrodes, the optimum (electrolysis time of 81.8 min, current density of 35 A/cm2, and mixing intensity of 45 rpm) color and sCOD removal were obtained 90.1% and 89.4%, respectively. Analysis and comparison of the data revealed that Fe rod electrodes delivered a better treatment performance than Fe plate electrodes, taking into account that the optimum electrolysis time and applied current density were considerably lower for the Fe rod electrodes. Overall, these results confirmed that the novel EC reactor using Fe rod electrodes can reduce the operating cost and be proposed as a pragmatic approach to remove high amount of color, COD, and suspended solids from licorice processing wastewater.

Study on the mechanism of tetracycline removal in electrocoagulation coupled with electro-fenton reaction system with Fe anode and carbon nanotube cathode

In this work, an efficient electrochemical system (Fe-CNT system) for the treatment of tetracycline (TC) was constructed using Fe plate anode and carbon nanotube (CNT) roller cathode. Compared with the traditional Fe-Fe electrocoagulation (EC) system, this Fe-CNT system exhibited higher TC removal rate and shorter reaction time. The best removal rate of 97.21% was achieved at pH of 7, the conductivity of 500 μS cm−1, initial TC concentration of 50 mg L-1, the voltage of 5 V, and reaction time of 25 min. The results demonstrated that the removal rate of total organic carbon was 52.79% at 25 min and 82.84% at 60 min, respectively. The excellent performance of the Fe-CNT system was mainly due to the use of CNT cathode slowed down the floatation in the system, which was conducive to the aggregation and growth of flocs. As a result, the flocs with larger size and more loose structure showed stronger adsorption and aggregation to organic molecules. At the same time, the concentration of hydrogen peroxide in-situ produced was in the range of 7.76 mg L-1 and 30.17 mg L-1. Furthermore, hydroxyl radical as the primary active specie was also produced on the cathode surface by electro-Fenton reaction, which could degrade TC rapidly. In addition, the intermediates involved in the degradation process of TC were identified, and the possible degradation paths were proposed. This work provides insights for improving the cathode utilization rate and removal ability of organic matter and adds a feasible option for the practical application of EC technology.

Room-Temperature Synthesis of Single Iron Site by Electrofiltration for Photoreduction of CO2 into Tunable Syngas

Developing a convenient and effective method to prepare single-atom catalysts at mild synthetic conditions remains a challenging task. Herein, a voltage-gauged electrofiltration method was demonstrated to synthesize single-atom site catalysts at room temperature. Under regulation of the graphene oxide membrane, a bulk Fe plate was directly converted into Fe single atoms, and the diffusion rate of Fe ions was greatly reduced, resulting in an ultralow concentration of Fe2+ around the working electrode, which successfully prevented the growing of nuclei and aggregating of metal atoms. Monatomic Fe atoms are homogeneously anchored on the as-prepared nitrogen-doped carbon. Owing to the fast photoelectron injection from photosensitizers to atomically dispersed Fe sites through the highly conductive supported N-C, the Fe-SAs/N-C exhibits an outstanding photocatalytic activity toward CO2 aqueous reduction into syngas with a tunable CO/H2 ratio under visible light irradiation. The gas evolution rates for CO and H2 are 4500 and 4950 μmol g-1 h-1, respectively, and the tunable CO/H2 ratio is from 0.3 to 8.8. This article presents an efficient strategy to develop the single-atom site catalysts and bridges the gap between heterogeneous and homogeneous catalysts toward photocatalytic CO2 aqueous reduction into syngas.

Corrosion protection coating of three-dimensional metal structure by electrophoretic deposition of graphene oxide

Corrosion protection of metals is of great importance in many applications. Electrophoretic deposition (EPD) is one of the most effective techniques to produce anticorrosive graphene coatings on metals. However, EPD coating on complex shaped surfaces, such as three-dimensional (3D) structures, has rarely been reported, despite its importance in practical applications of metal anti-corrosion. In this study, we prepared three kinds of graphene oxide (GO) nanosheets with large, medium, and small lateral sizes through simple dispersion methods, such as stirring, sonication, and homogenizer, respectively, and coated them on the surface of two-dimensional (2D) steel (Fe) plates and 3D Fe rods by the cathodic EPD process. As the lateral size of the coated GO sheets increased, a smoother and thicker coating layer was formed on the Fe plate, which resulted in better corrosion resistance. In addition, novel EPD equipment with multi-electrodes has been developed to coat GO sheets onto 3D metal structures. The GOs were successfully coated on 3D Fe rod using the EPD equipment with multiple electrodes, leading to improvement of the corrosion resistance while maintaining the high electrical conductivity. This approach provides a viable and scalable route for using graphene oxide coatings to protect metal surfaces from corrosion.

Fabrication of \u03b3-Fe2O3 Nanowires from Abundant and Low-cost Fe Plate for Highly Effective Electrocatalytic Water Splitting

Water splitting is thermodynamically uphill reaction, hence it cannot occur easily, and also highly complicated and challenging reaction in chemistry. In electrocatalytic water splitting, the combination of oxygen and hydrogen evolution reactions produces highly clean and sustainable hydrogen energy and which attracts research communities. Also, fabrication of highly active and low cost materials for water splitting is a major challenge. Therefore, in the present study, γ-Fe2O3 nanowires were fabricated from highly available and cost-effective iron plate without any chemical modifications/doping onto the surface of the working electrode with high current density. The fabricated nanowires achieved the current density of 10 mA/cm2 at 1.88 V vs. RHE with the scan rate of 50 mV/sec. Stability measurements of the fabricated Fe2O3 nanowires were monitored up to 3275 sec with the current density of 9.6 mA/cm2 at a constant potential of 1.7 V vs. RHE and scan rate of 50 mV/sec.

The effect of oxidation temperature on the thermoelectric performance of a plate-type thermoelectric power generator

This paper reports on the effect of oxidation temperature on the thermoelectric performance of a plate-type thermoelectric power generator. Recently, thermoelectric power generation methods have attracted considerable attention as energy harvesting technologies. Among these, a plate-type thermoelectric power generator in which an Al layer is deposited on a Fe plate has been reported. Although oxidation of the surface of the Fe plate was verified experimentally to be effective in enhancing the thermoelectric performance, the kind of oxide suitable for a plate-type generator has yet to be investigated. In this study we oxidized the surface of an Fe plate at different temperatures, and plate-type thermoelectric power generators having various oxides at the bi-metallic interface were fabricated. It was found that Fe2O3 made a large contribution to increasing the Seebeck coefficient compared with Fe3O4. The generator with a bi-metallic interface oxidized at 400 °C showed the maximum power, the value being 1.4 μW at a temperature difference of 40 °C. Furthermore, we developed a theoretical model to predict the maximum power of a plate-type generator based on solid-state physics, and the predicted values were in good agreement with the experimental ones.

Ferric chloride leaching of antimony from stibnite

A circulatory hydrometallurgical process: ferric trichloride (FeCl3) leaching of antimony sulfide (Sb2S3) (production of Sb by replacing it with iron) followed by membrane electrowinning of ferrous chloride (FeCl2), was developed to cleanly extract Sb from stibnite. First, Sb was leached (leaching efficiency >98%), using FeCl3 as leaching reagent, under the following optimum conditions: temperature of 50 °C, liquid-to-solid ratio of 8:1, α(FeCl3) of 1.2 (where α represents the excess coefficient), and time of 1 h. Then, an Fe plate was used to replace Sb from the leaching solution using a two-step process. Approximately 96.86% of the Sb in the leaching solution was extracted, and pure FeCl2 was obtained. Finally, the FeCl2 solution was subjected to membrane electrowinning to regenerate the FeCl3 solution used as leaching solution at the anode and the Fe plate used as cathode. The optimal membrane electrowinning conditions were as follows: current density of 300 A/m2, temperature of 40 °C, and pH = 2.0. Both the anode and cathode current efficiencies were higher than 99%. The FeCl3 solution and Fe plate were reused for the leaching process and Sb replacement, respectively, while superfluous metallic Fe was open circuited. This novel process presents several advantages, including recirculating all solutions, high current efficiency, and low reagent consumption.

A regression-tree multilayer-perceptron hybrid strategy for the prediction of ore crushing-plate lifetimes

Highly tensile manganese steel is in great demand owing to its high tensile strength under shock loads. All workpieces are produced through casting, because it is highly difficult to machine. The probabilistic aspects of its casting, its variable composition, and the different casting techniques must all be considered for the optimisation of its mechanical properties. A hybrid strategy is therefore proposed which combines decision trees and artificial neural networks (ANNs) for accurate and reliable prediction models for ore crushing plate lifetimes. The strategic blend of these two high-accuracy prediction models is used to generate simple decision trees which can reveal the main dataset features, thereby facilitating decision-making. Following a complexity analysis of a dataset with 450 different plates, the best model consisted of 9 different multilayer perceptrons, the inputs of which were only the Fe and Mn plate compositions. The model recorded a low root mean square error (RMSE) of only 0.0614 h for the lifetime of the plate: a very accurate result considering their varied lifetimes of between 746 and 6902 h in the dataset. Finally, the use of these models under real industrial conditions is presented in a heat map, namely a 2D representation of the main manufacturing process inputs with a colour scale which shows the predicted output, i.e. the expected lifetime of the manufactured plates. Thus, the hybrid strategy extracts core training dataset information in high-accuracy prediction models. This novel strategy merges the different capabilities of two families of machine-learning algorithms. It provides a high-accuracy industrial tool for the prediction of the full lifetime of highly tensile manganese steel plates. The results yielded a precision prediction of (RMSE of 0.061 h) for the full lifetime of (light, medium, and heavy) crusher plates manufactured with the three (experimental, classic, and highly efficient (new)) casting methods.

The efficiency of the electrocoagulation process in reducing fluoride: application of inductive alternating current and polarity inverter

In this study, using hybrid Al and Fe plate electrodes in an electrochemical cell by using inductive alternating current and polarity inverter as an alternative method for decreasing fluoride in drinking water sequentially, by the electrocoagulation process has been evaluated. The effect of operational parameters such as the type of current, paired hybrid electrodes and polarity inverter, pH, current density, electrolysis time, charge loading and flow rate on the percent of fluoride removal along with the amount of energy and electrode consumed and amount of sludge produced was evaluated. In the following optimum operation conditions: paired hybrid Al–Fe electrodes with polarity inverter, pH = 6, current density = 12 mA/cm2, electrolysis time = 40 min, charge loading 0.609 Faradays/m3 and flow rate 75 ml/min, the efficiency of fluoride removal, energy and electrode consumption, flow efficiency, amount of sludge produced and sedimentation capacity were, respectively, 95% (from initial 4.93 to 0.24 mg/l), 0.9 kWh/m3, 1.42 kg/m3, 110%, 0.108 kg/m3 and 0.073 l/g. The results showed that the electrocoagulation process by using alternating current and polarity inverter is a very efficient method for removing fluoride from drinking water.

Fe-assisted chemical bath deposition of highly oriented Cu2O films and formation of ZnO nanorods/Cu2O heterojunctions

Cuprous oxide (Cu2O) films composed of highly oriented polygonal-prism-shaped grains were grown on Au/Ti/Si(100) substrates from the aqueous solutions of Cu(NO3)2·3H2O and C6H12N4 by the chemical bath deposition with the assistance of a piece of Fe plate immersed in the CBD solution (Fe-assisted CBD). Morphologies of the Cu2O films on the Au/Ti/Si(100) substrates were quite different from those on the Au/SiO2/Si(100) substrates, reflecting the difference in morphology between both the Au seed layers. The increase in Fe plate area was found to contribute to the increase in film thickness and the decrease in resistivity. Moreover, ZnO nanorods (NRs) were grown on the Cu2O films by usual CBD using the aqueous solutions of Zn(NO3)2·6H2O and C6H12N4 with different concentrations. The increase in the concentration of the CBD solution resulted in the increase in the density of the NRs followed by the enhancement of near-band-edge photoluminescence.

Treatment of paper-recycling wastewater by electrocoagulation using aluminum and iron electrodes.

Treatment of industrial wastewater by electrocoagulation (EC) is one of the most efficient methods to remove pollutants. Paper-recycling wastewater is a complex mixture containing toxic and recalcitrant substances, indicating complexity and difficulty of its treatment. The aim of the present study was to assess the effectiveness of paper-recycling wastewater treatment by EC process using aluminum (Al) and iron (Fe) plate electrodes. Removal of chemical oxygen demand (COD), total suspended solids (TSS), color and ammonia from paper-recycling mill effluent was evaluated at various electrolysis times (10–60 min), voltage (4–13 V) and pH (3.5–11). The optimum process conditions for the maximum removal of COD, TSS, color and ammonia from paper-recycling industry wastewater have been found to be pH value of 7, treatment time of 60 min and voltage of 10 V. Under optimum operating conditions, the removal capacities of COD, TSS, color and ammonia were 79.5%, 83.4%, 98.5% and 85.3%, respectively. It can be concluded that EC could be considered as an effective alternative for treatment of paper-recycling wastewater.

Electrochemical Formation of Dy-Fe and Nd-Fe Alloys in Molten CaCl2-LiCl Systems

Here we study the recovery process of rare earth metals from Nd magnet scraps via electrolysis in a molten salt and with an alloy diaphragm. In the present study, the electrochemical formation of Dy-Fe and Nd-Fe alloys, which was an important step of the recovery process, was investigated in molten CaCl2-LiCl systems at 873 K. Two Dy-Fe alloy samples were prepared by potentiostatic electrolysis of Fe plate electrodes at 0.30 V (vs. Li+/Li) and 0.50 V for 1 h in CaCl2-LiCl-DyCl3 (0.50 mol% added). The formation of DyFe5 was suggested by X-ray diffraction (XRD). Potentiostatic electrolysis was also conducted at 0.30 V and 0.50 V for 1 h using Fe plate electrodes in CaCl2-LiCl-NdCl3 (0.50 mol% added). XRD analysis suggested the formation of Nd2Fe17 for both samples. The equilibrium potentials for (DyFe5+Fe) and (Nd2Fe17+Fe) coexisting phases were indicated.

Electrochemical Formation of Dy-Fe and Nd-Fe Alloys in Molten CaCl2-LiCl Systems

We proposed a new separation and recovery process for rare earth (RE) metals from scraps using molten salt and an alloy diaphragm. RE containing scrap is used as the anode. A RE-transition metal (TM) alloy is used as the diaphragm, which functions as a bipolar electrode. During electrolysis, all the RE metals in the anode are dissolved in the molten salt as RE ions. One or several specific RE ions are selectively reduced to form RE-TM alloys on the alloy diaphragm according to their formation potentials and/or alloying rates. Subsequently, the RE atoms chemically diffuse through the alloy diaphragm and are dissolved into the molten salt as RE ions in the cathode room. The permeated RE ions are finally deposited on the Mo or Fe cathode as RE metals. The RE ions remaining in the anode room can be collected by electrolysis using another cathode in the anode room. Almost all impurities remain in the anode room as residue or anode slime. The present study focused on Fe alloys as alloy diaphragms. The electrochemical formation of Dy-Fe and Nd-Fe alloys in molten CaCl2-LiCl systems at 873-973 K. To confirm the formation of Dy-Fe alloys, potentiostatic electrolysis was conducted at 0.30 V(vs. Li+/Li) and 0.50 V for 1 h using Fe plate cathodes at 873 K in CaCl2-LiCl-DyCl3 (0.50 mol% added). The two samples were analyzed by XRD. The alloy phases were identified as DyFe2 or DyFe3. On the other hand, potentiostatic electrolysis was conducted at 0.30 V and 0.50 V for 1 h using Fe plate cathodes at 873 K in CaCl2-LiCl-NdCl3 (0.50 mol% added). From the result of XRD analysis, it was found that several Nd-Fe phases were formed.