Copper Anode Research Articles

Nanorods grown by copper anodizing in sodium carbonate

Self-organized anodization of copper in 0.1 M Na2CO3 electrolyte was studied in order to obtain nanostructured oxide surface on the metal substrate. Linear sweep voltammetry (LSV) revealed that the most suitable voltage range for anodic film formation is from 3 to 31 V. In this range (except between 3 and 7 V), the oxide is formed as nanorods, with the diameter of the anodically grown nanostructures increasing with the applied voltage. The smallest diameter of the nanorods was found to be 28 ± 9 nm (15 V), while the greatest diameter was 109 ± 15 nm (30 V). X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Raman spectroscopy pointed out that the nanorods consist of crystalline CuO (tenorite) and Cu2O (cuprite), and amorphous Cu(OH)2. Moreover, the greater the anodizing voltage, the greater the CuO content versus Cu2O. The formed nanostructured materials may find applications in photocatalysis and catalytic electrochemical reduction of carbon dioxide into light hydrocarbons.

The influence of electrolyte usage on the growth of nanostructured anodic films on copper in sodium carbonate aqueous solution

Anodization of copper was performed in 0.1 M K2CO3 at 25 and 50 V. In order to study the influence of the electrolyte usage, samples were anodized in fresh electrolyte and electrolyte that was applied for anodizing for 2, 4 and 6 h. It was found that during anodization, the current oscillates with time. It means that there are cycles of adsorptions and delaminations of the anodic film of the samples. Moreover, the longer the electrolyte is used, the faster steady state of current densities without oscillations is achieved and the greater the current densities are. According to the Pourbaix diagram, the greater concentration of the water soluble copper species, the greater the CuO passivity field, thus the anodic oxides are formed much easier. For this reason, X-ray diffraction patterns revealed increasing content of tenorite phase (CuO) over cuprite (Cu2O) when the electrolyte is being re-used. For electrolytes pre-used for 6 h, no cuprite was found in the samples. Moreover, the longer the pre-usage of the electrolyte, the smaller the diameter of the grown nanowires. For anodizing performed at 25 V, nanowire diameter decreases from 55 ± 12 nm to 36 ± 7 nm (electrolyte pre-used for 6 h) in a linear manner.

Commencing an Acidic Battery Based on a Copper Anode with Ultrafast Proton-Regulated Kinetics and Superior Dendrite-Free Property.

Building aqueous acidic batteries is in its infancy. There are several sporadic attempts that show desirable electrochemical performance, especially rate stability and high power density. The direct use of a metal anode is regarded as the best protocol for fabricating metal-based batteries. However, introducing an acid-tolerant and electrochemically reversible metal anode into an acidic aqueous battery system remains a considerable challenge. In this work, copper (Cu) metal is used as a reversible metal anode to match acidic regimes with a nearly 100% deposition-dissolution efficiency. The reaction kinetics and mechanism of the Cu anode can be regulated by protons with 400% kinetic acceleration compared with a mild electrolyte. In addition, the anode exhibits a dendrite-free morphology after cycling due to the surface roughening effect, which is different from the morphologies of widely used Zn- and Li-metal anodes. When coupled with the Prussian blue analog as cathodes, the battery delivers ultrafast kinetics of 1830 W kg-1 at 75 C, which is comparable to the power performance of supercapacitors. Long-term cyclic stability is evaluated, where the capacity retention is 85.6% after 5000 cycles. Finally, flexible fiber-shaped acidic Cu-based batteries are demonstrated for potential wearable applications.

Electrically-launched mm-sized hypervelocity projectiles

An electrothermal research gun capable of firing small cylindrical projectiles up to 4 km/s has been developed. While electromagnetic forces certainly exist in the system, it is not an electromagnetic launch system, but rather utilizes an electrical arc to produce a rapidly expanding gas that is used as the working fluid. A pointed copper anode is insulated such that the arc initiates only at the very tip, while the electrical circuit is completed through both the projectile and the barrel. Experiments show that copper vapor from the eroding copper electrode is the most likely working fluid of the gun, however, a portion of the aluminum projectile is also eroded. The design was directly aided by simulations performed using the multiphysics hydrocode ALEGRA developed by Sandia National Laboratories. Simulations included investigating the anode tip shape as well as limiting the expansion of the chamber due to the rapid expansion of gasses caused by the arc. Comparisons of projectile velocity profiles from Photon Doppler Velocimetry, barrel expansion, and pellet erosion with the ALEGRA results were utilized as benchmarks, leading to significant velocity gains for given energy inputs.

Dependence of the plasma composition in the low-current vacuum arc discharge on CuCr cathode on the current value and surface conditions

The dependence of the ion flux mass-charge composition from the vacuum arc plasma with the CuCr cathode on a value of the discharge current was investigated via the Thomson spectrometer with automatic signal registration and analysis. The microsecond arc was formed in a millimeter gap between CuCr cathode and copper anode under high vacuum conditions. The arc current was changed within the range from a few to tens of ampere. At the highest currents the plasma composition corresponded the elemental composition of the cathode surface. The fraction of the chromium ions significantly decreased with the arc current decreasing below 30 A. There was noticeable increasing of the fraction of the chromium ions in the plasma at the discharge currents near the threshold values for the cathode materials. The effect appeared on coarse-grained non-melted cathode surfaces, and vanished after a multiple arcing.

Generation of atmospheric pressure plasma in molecular gas flows

We have investigated an atmospheric pressure discharge, similar to a plasma jet, in the N2 and CO2 gas flows. We have also carried out an experimental modeling with the argon Ar flow. It has been shown that the use of a tantalum cathode and a copper anode provides a stable discharge in the nitrogen and carbon dioxide flows. We have studied the dependence of the discharge voltage on the discharge current (VAC). Optical emission spectra of discharge glow was investigated also. Using a single probe and a thermocouple, we have studied the axial distribution of the floating potential in the plasma jet and the gas temperature at the anode nozzle exit of the plasma generator. In applying to polymer surface modification, we have determined the optimal operation conditions: gas flow rate up to 5 l·min−1; continuous or pulsed working regime; discharge current about 80 mA; pulse duration up to 10 µs; pulse repetition rate 50 kHz.

Effect of Cryogenic Treatment on Extruded Copper Structures

To improve the quality of electroplated copper anodes and reduce the amount of anode mud, it is necessary to further refine copper grains. In the electronics industry, this is typically accomplished by either extrusion or cryogenic treatment. In this study, samples were subjected to different cryogenic treatment periods, and SEM, EDS, XRD, and hardness tests were performed. It was confirmed that a sub-grain boundary was formed due to the disappearance of vacancies and an increase in dislocations after the cryogenic treatment of extruded copper, which improved the grain refinement and hardness. At longer treatment times, the combination and entanglement of dislocations reduced the strengthening effect, and the copper diffraction peaks changed. However, the distribution of trace phosphorus did not change with the grain refinement distribution. Therefore, the results confirm that cryogenic treatment can be used to refine the grains of extruded copper.

Design of X-ray units for inspection applications (review)

A review of the structural elements (individual components, printed circuit boards, etc.) of X-ray systems intended for inspection of electronic products is presented. The basic principles of constructing such systems and typical composition of the equipment capable of providing the minimum necessary functionality are considered. Among the main technical characteristics an emphasis is made on the resolution power, which depends on the pixel size and thickness of the scintillator layer of the X-ray detector, as well as on the size of the effective focal spot of the X-ray tube. Comparative analysis of the advantages and shortcomings of clastic (open type) and sealed (closed type) X-ray tubes – one of the main nodes of such systems-is carried out. A structural diagram of a clastic X-ray tube is presented along with and the characteristics of domestic and foreign developments. The main disadvantages of the systems based on clastic tubes are considered. Large dimensions, large weight, relative complexity of the construction, presence of the vacuum-tight collapsible connections, the necessity of using a pumping system providing high vacuum, the necessity of high-voltage training of the tube assemblies after their replacement, and high cost are noted separately. The design of sealed off BS microfocus X-ray tube and radiation sources on their base which can be used in the development of domestic X-ray systems are briefly described. The diameter and length of the metal-glass cylinder tube are 75 and 315 mm, and the diameter and length of the copper anode tube 10 and 100 mm, respectively. A tungsten target is deposited on a beryllium substrate (X-ray tube exit window) with a thickness of 0.2 mm. The minimum focal length during x-ray photography is 0.5 mm. A comparative analysis of the characteristics of a clastic (collapsible) X-ray tube with continuous pumping and an X-ray tube sealed from an exhaust cart revealed the possibility of successful use of sealed tubes in modern X-ray systems used for inspection applications.

Preparation and in vitro antibacterial properties of anodic coatings co-doped with Cu, Zn, and P on a Ti–6Al–4V alloy

In this study, copper (Cu) and zinc (Zn) as well as phosphorus (P) were co-doped into a Ti–6Al–4V titanium alloy via micro-arc oxidation (MAO). The entrance mechanisms of Cu and Zn into MAO coatings were investigated by an orthogonal experiment. The results show that Cu and Zn in Cu–Zn–P coatings separately exist mainly in the forms of Cu2O and Zn3(PO4)2. The Cu content in MAO coating increases with increasing EDTA-CuNa2 and KOH concentrations and decreasing phytic acid concentration but is nearly independent of EDTA-ZnNa2 concentration. The Zn content increases with increasing EDTA-ZnNa2 concentration and decreasing EDTA-CuNa2 concentration, indicating the competing effect between Cu and Zn for incorporation into Cu–Zn–P coatings. Compared with Zn ions, Cu ions do not readily enter anodic coatings due to their simultaneous involvement in coating formation on the anode and precipitation of metallic copper on the cathode. Cu–Zn–P coatings with appropriate amounts of Cu and Zn achieve excellent antibacterial ability against Escherichia coli (E.coli), Staphylococcus aureus (S.aureus), and Methicillin-resistant Staphylococcus aureus (MRSA). These antibacterial properties, in addition to excellent cytocompatibility, make Cu–Zn–P coatings as promising materials for orthopedic applications.

A fully coupled diffusional-mechanical finite element modeling for tin oxide-coated copper anode system in lithium-ion batteries

Finite element (FE) modeling is a powerful method to investigate the volume change induced by lithium diffusion and the corresponding mechanical degradation for a deeper understanding of (dis)charging process in lithium-ion batteries. However, FE studies on the diffusion-stress interaction taking into consideration the effect of hydrostatic stress gradient in three-dimensional complex structures of electrodes are insufficient and limited. Higher charging rate can cause the high gradient of hydrostatic pressure which affects the diffusion flux in the electrode. Here, we present a fully coupled diffusional-mechanical FE model, which simultaneously solves the equations relevant to the diffusion and the mechanical behavior, by considering the mechanical contact between a tin oxide active layer and the hollow struts of a copper scaffold, as well as the pressure gradient. The numerically computed strains in the copper struts are in good agreement with the experimental strain data, previously measured in operando using X-ray diffraction. Calculations also show that large stresses are induced in the active layer during lithiation, causing elastic tensile strains in the scaffold which displays some residual strains after full discharging. The active layer is predicted to undergo plastic deformation during cyclic (dis)charging, and the amount of which grows significantly with increasing charging rate.

Synthesis of bimetallic Cu‐Ag nanoparticles prepared by DC high voltage electrochemical method

AbstractCopper‐silver bimetallic nanoparticles (NPs) can be prepared by electrochemical high voltage DC using silver and copper anodes in double distilled water. Bimetallic nano formation of Cu‐Ag‐NPs were performed by dissolving the Ag anode in anodic dissolved Cu solution or in the Cu NPs solution. The dependence of the DC current and the amount of electricity on the time show the reaction with a 200 mm electrode gap with formation of electronic plasma. The product obtained at 5 kV had the same characteristics as AgNPs with UV‐Vis spectrum: 420 nm, particle size distribution was mainly in small areas of 100 nm, zeta potential had value up to ‐80.6 mV as well as the good ability to kill bacteria.

Development of plasma reactor design for synthesis of copper nanoparticles using multi-scale simulation

On the basis of the hybrid hydrodynamic model for the gas discharge, numerical experiments were performed. The main parameters of the electric discharge of a direct current with copper cathode and anode were obtained. The obtained data were used as the main conditions for molecular-dynamics simulations of the copper vapor nucleation process in the argon. The results of the simulation formed the basis for the development of an experimental setup for the plasma synthesis of copper nanoparticles.

Eddy current separation for recovering aluminium and lithium-iron phosphate components of spent lithium-iron phosphate batteries.

With the rapid development of the electric vehicle market since 2012, lithium-iron phosphate (LFP) batteries face retirement intensively. Numerous LFP batteries have been generated given their short service life. Thus, recycling spent LFP batteries is crucial. However, published information on the recovery technology of spent LFP batteries is minimal. Traditional separators and separation theories of recovering technologies were unsuitable for guiding the separation process of recovering metals from spent LFP batteries. The separation rate of the current method for recovering spent LFP batteries was rather low. Furthermore, some wastewater was produced. In this study, spent LFP batteries were dismantled into individual parts of aluminium shells, cathode slices, polymer diaphragms and anode slices. The anode pieces were scraped to separate copper foil and anode powder. The cathode pieces were thermally treated to reduce adhesion between the cathode powder and the aluminium foil. The dissociation rate of the cathode slices reached 100% after crushing when the temperature and time reached 300℃ and 120 min, respectively. Eddy current separation was performed to separate nonferrous metals (aluminium) from aluminium and LFP mixture. The optimized operation parameters for the eddy current separation were feeding speed of 1 m/s and magnetic field rotation speed of 4 m/s. The separation rate of the eddy current separation reached 100%. Mass balance of the recovered materials was conducted. Results showed that the recovery rate of spent LFP can reach 92.52%. This study established a green and full material recovery process for spent LFP batteries.

Hydrogen Gas Production using Electro-activated Carbon Catalyst from Coconut Shells

The synthesis of heterogeneous carbon catalyst using electro-activation method has been carried out to assess the effect of temperature on surface morphology of hydrogen production and the surface area of the carbon catalyst as well as characterization of hydrogen production that was resulted. The electrolyte solution of NaOH with a concentration of 2.7 M which was produced from 2 grams of carbon and 25 ml of distilled water was used for electro-activation process. The activation process was taken place with a current of 3 A for 120 minutes and the variation of carbonization temperature of 1000, 1100 and 1200 °C. The electrode system that was used in the process comprised a carbon cathode and copper anode. The results of carbon mass yield testing indicated that purification of charcoal applied at high temperature. The optimum amount of gas with an average rate of 9.19 ml/min/gr Al for a time of 1 hour was produced from carbonized catalyst at carbonization temperature of 1200 °C. The SEM-EDS examination indicated that the reacted product consisted of a mixture of Al(OH)3 and carbon catalysts which would be reprocessed through the re-electro-activation. The characterization of Brunauer-Emmet-Teller (BET) of the surface area of catalyzed carbon shown a value of 394.456 m2/g; while the result test of Scanning Electron Microscope (SEM) shown that the morphology of surface layer tends to be more pores after carbon catalyzed was used with the concentration of NaOH electrolyte solution of 2.7 M. Results of Fourier Transform Infra-Red (FTIR) analysis also shown the formation of new carboxyl functional groups (O-H) in the wavelength range 464.41 cm−1.

Selenium(VI) removal from caustic solution by synthetic Ca–Al–Cl layered double hydroxides

Abstract To extract selenium(VI) from the highly caustic leachate of copper anode slime, the Ca–Al–Cl layered double hydroxides (Ca–Al–Cl–LDHs) with a formula of Ca2Al(OH)6Cl·2H2O by three co-precipitation methods were synthesized. A plate-like morphology and hexagonal crystal structure with typical mineral phases and functional groups were identified by the FESEM, XRD, FTIR, BET and XPS analysis. The forward feeding sample exhibits the best adsorption capacity of Se(VI). The factor experiments then reveal a favorable adsorption process with low temperature, low NaOH concentration and high adsorbent dosage. Furthermore, the adsorption kinetics and isotherm parameters can be well described by the Langmuir isotherm and the pseudo-second-order models, respectively. Accordingly, the maximum adsorption amount of Se(VI) onto Ca–Al–Cl–LDHs reaches 188.6 mg/g at 50 °C.

Computational Fluid Dynamics Modeling of Combustion Characteristics of a CH4/O2 Combustor in a Copper Anode Furnace.

With the rapid depletion of high-yield copper mineral resources and the accumulation of secondary copper resources, the recycling of secondary copper is gaining popularity in the copper industry. A copper anode furnace, often used in copper recycling, usually relies on methane combustion to melt copper scraps. In this work, a computational fluid dynamics (CFD) model of pure oxy-methane combustion is established to investigate the combustion characteristics of the CH4/O2 combustor in the copper anode furnace. The model is validated by comparing the simulation results with experimental measurements. The effects on flame length and temperature distribution are investigated under various fuel velocities, oxidizer velocities, and oxidizer temperatures. The results indicate that flame length and temperature distribution increase as the fuel velocity and oxidizer temperature increase, and decrease with the increase in oxidizer velocity. The flame length and temperature distribution always show an increasing trend with the increasing equivalence ratio. Based on the recycling capacity of the copper anode furnace, this validated CFD model can be used to optimize the operation parameters for controlling flame length and temperature distribution.

Sequential Recovery of Heavy and Noble Metals by Mussel-Inspired Polydopamine-Polyethyleneimine Conjugated Polyurethane Composite Bearing Dithiocarbamate Moieties.

Dithiocarbamate-grafted polyurethane (PU) composites were synthesized by anchoring dithiocarbamate (DTC) as a chelating agent to the polyethyleneimine-polydopamine (PE-DA)-functionalized graphene-based PU matrix (PE-DA@GB@PU), as a new adsorbent material for the recovery of Cu2+, Pb2+, and Cd2+ from industrial effluents. After leaching with acidic media to recover Cu2+, Pb2+, and Cd2+, dithiocarbamate-grafted PE-DA@GB@PU (DTC-g-PE-DA@GB@PU) was decomposed and PE-DA@GP was regenerated. The latter was used to recover Pd2+, Pt4+, and Au3+ from the copper leaching residue and anode slime. The present DTC-g-PE-DA@GB@PU and PE-DA@GB@PU composites show high adsorption performance, effective separation, and quick adsorption of the target ions. The morphologies of the composites were studied by scanning electron microscopy and their structures were investigated by Fourier transform infrared (FT-IR) spectroscopy and Raman spectroscopy. The effects of pH values, contact time, and initial metal ion concentration conditions were also studied. An adsorption mechanism was proposed and discussed in terms of the FT-IR results.

Growth of Layered Copper–Alkanethiolate Frameworks from Thin Anodic Copper Oxide Films

Fil: Arisnabarreta, Nicolas. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones en Fisico-quimica de Cordoba. Universidad Nacional de Cordoba. Facultad de Ciencias Quimicas. Instituto de Investigaciones en Fisico-quimica de Cordoba; Argentina

Electrochemical corrosion mechanisms of nickel-aluminium bronze with different nickel contents using the rotating disc electrode

The open circuit potential, cathodic and anodic polarisation characteristics of nickel-aluminium bronze (NAB) with different nickel contents in 3.5 wt.% NaCl solution were investigated under well-defined hydrodynamic conditions. The results showed that irreversible cathodic oxygen reduction reaction was under kinetic control, whereas the reversible anodic copper dissolution reaction was under mixed transport-kinetic control. The increase in Ni content decreased the total amounts of α phase and β' phase in the microstructures of NAB alloys, resulting in the decrease in both cathodic kinetic current and anodic current, and thus improved the corrosion resistance of NAB alloys under flowing conditions.

Electrochemical synthesis of copper oxide particles with controlled oxidation state, shape and size

Anodic polarization of copper in ethanol-water solutions with LiCl leads to formation of microparticles composed of copper compounds. For the anhydrous solution a blue precipitate of Cu2(OH)3Cl is synthesized. In case of low water content spherical Cu2O microparticles are formed with the size slightly increasing with H2O concentration. Needle-like shaped particles of CuO are obtained for water content above 25%. The final product is formed in secondary reactions between particles originating from anodic copper dissolution and water or alcohol decomposition on electrodes. For high water content more hydroxyl groups are obtained on cathode, whereas more aldehyde is formed on anode, when ethanol dominates. The concentration of these intermediate products determines the phase and morphology of the final product.