Copper Foam Research Articles

Boosted direct electrochemical reduction of As(III) from arsenic wastewater via Cu(II)-assisted codeposition on a CuIn alloy electrode

Arsenic contamination is a severe environmental problem. A promising strategy for addressing this issue is the direct conversion of highly toxic As(III) to less toxic elemental arsenic (As(0)) using electrochemical reduction technology. In this study, a novel CuIn alloy nanoparticles-modified copper foam (CuIn NPs/CF) was prepared as an efficient cathode for the electrocatalytic reduction of highly mobile As(III) to solid As(0). Density functional theory (DFT) results revealed that the Cu-In bimetallic system exhibited weaker H atom bonding, and the Cu-ln surface was more favorable for the adsorption of *AsO₃ species than the Cu surface. Compared to the pristine CF electrode, CuIn NPs/CF was demonstrated to effectively suppressed the hydrogen evolution reaction with an enlarged hydrogen evolution potential of 1.45 V, and displayed a superior As(0) recovery yield. The conversion of As(III) to As(0) was further enhanced by adding Cu²⁺ to the electrolyte, facilitating a Cu-As co-deposition process. Notably, the CuIn NPs/CF electrode achieved an As(0) recovery yield of 5.38 mg cm⁻² after eight successive recycling tests. This work not only presents a green and sustainable strategy for As(III) removal, but also provides valuable insights into the rational design of Cu-based alloy cathodes for electrocatalytic reduction.

Electrochemical hydrogen storage using SrFe12O19 surface-immobilized polyoxometalate

A tri-nickel substituted Keggin-type polyoxometalate (PMo9Ni3O37) was synthesized and subsequently immobilized on the surface of the M-type strontium hexaferrite (SrFe12O19) via the sol-gel method. The investigation of hydrogen storage capacity for the synthesized PMo9Ni3O37@SrFe12O19 nanocomposite was conducted through electrochemical methodologies employing chronopotentiometry (CP). A conventional three-electrode configuration employing copper foam coated with PMo9Ni3O37@SrFe12O19 served as the working electrode and was examined across a current range of ±1.5 mA. The charge and discharge of the experimental procedure indicated the substantial potential of the PMo9Ni3O37@SrFe12O19 nanocomposite in the hydrogen storage process, which was determined 3125 mAh/g during the discharge phase. The successful synthesis was corroborated thorough FT-IR, UV-vis, XRD, SEM, EDX, and BET surface area analysis techniques by examining the characteristic absorption wavelengths or reflection patterns. The size of the nanoparticles was determined through SEM analysis yielding a diameter of 36.76 nm, and using the Scherrer equation, a diameter of 29.22 nm was obtained.

Elimination of Methyl Orange Dye with Three Dimensional Electro-Fenton and Sono-Electro-Fenton Systems Utilizing Copper Foam and Activated Carbon

Elimination of Methyl Orange Dye with Three Dimensional Electro-Fenton and Sono-Electro-Fenton Systems Utilizing Copper Foam and Activated Carbon

High-Flux Steady-State Demulsification of Oil-In-Water Emulsions by Superhydrophilic-Oleophobic Copper Foams with Ultra-Small Pores Under Pressure.

3D superwetting materials struggle to maintain high-flux steady-state demulsification for oil-in-water emulsions because the accumulated oil within the material is difficult to discharge rapidly. The water flow shear force can swiftly remove the oil from the anti-fouling surface. In this study, by introducing nanofibers and carbon nanotubes and chemical modification, a superhydrophilic-oleophobic copper foam with pores of several micrometers is prepared, which can achieve a continuous demulsification process with steady-state flux over 57000 Lm-2h-1 for oil-in-water emulsions and rapid hydraulic-driven oil release under an additional pressure of 5kPa. Thanks to the ultra-small pores of the copper foam, the steady-state demulsification efficiency can be still maintained at over 97.5%. During the demulsification process, the accumulation of oil and surfactants within the copper foam can be maintained at low levels, achieving dynamic equilibrium. With the aid of second-stage superhydrophilic copper mesh, the demulsified oil-water mixtures can be rapidly separated. This high-flux, steady-state, and efficient demulsification process shows great potential for industrial applications.

X-ray ghost imaging with a specially developed beam splitter.

X-ray ghost imaging with a crystal beam splitter has advantages in highly efficient imaging due to the simultaneous acquisition of signals from both the object beam and reference beam. However, beam splitting with a large field of view, uniform distribution and high correlation has been a great challenge up to now. Therefore, a dedicated beam splitter has been developed by optimizing the optical layout of a synchrotron radiation beamline and the fabrication process of a Laue crystal. A large field of view, consistent size, uniform intensity distribution and high correlation were obtained simultaneously for the two split beams. Modulated by a piece of copper foam upstream of the splitter, a correlation of 92% between the speckle fields of the object and reference beam and a Glauber function of 1.25 were achieved. Taking advantage of synthetic aperture X-ray ghost imaging (SAXGI), a circuit board of size 880 × 330 pixels was successfully imaged with high fidelity. In addition, even though 16 measurements corresponding to a sampling rate of 1% in SAXGI were used for image reconstruction, the skeleton structure of the circuit board can still be determined. In conclusion, the specially developed beam splitter is applicable for the efficient implementation of X-ray ghost imaging.

Cu-Bi Bimetallic Catalysts Derived from Metal-Organic Framework Arrays on Copper Foam for Efficient Glycine Electrosynthesis.

Glycine as one of the most abundant amino acids in human proteins, with extensive applications in both life and industry, is conventionally synthesized through complex procedures or toxic feedstocks. In this study, we present a facile and benign electrochemical pathway for synthesis of glycine through reductive coupling of glyoxylic acid and nitrate over a copper-bismuth bimetal catalyst derived from a metal-organic framework (MOF) array on copper foam (Cu/Bi-C@CF). Remarkably, Cu/Bi-C@CF achieves a fantastic selectivity of 89%, corresponding a high Faraday efficiency of 65.9%. From control experiments, introduction of Bi caused the binding energy of Cu shift to lower state, which leads to a high selectivity towards the formation of key hydroxylamine intermediate rather than ammonia product, facilitating the formation of oxime and providing additional sites for subsequent hydrogenation reaction on the way to glycine. Moreover, the MOF array derivation ensures the effective dispersion of Bi and enhances the stability of Cu/Bi-C@CF. This innovative approach not only presents sustainable pathways for the production of value-added organonitrogen compounds utilizing readily available carbon and nitrogen sources, but also provides novel insights into the design of multistage structural catalysts for sequential reactions.

Flexible Terahertz Broadband Absorber Based on a Copper Composite Film.

Terahertz absorbers play a crucial role in terahertz detectors, radar stealth, electromagnetic shielding, and other fields. However, the design and fabrication of flexible terahertz broadband absorbers remain a challenge at present. Here, we demonstrated a terahertz broadband absorber based on a copper composite film (CCF) consisting of a copper foam and an organic silica gel doped with Fe3O4 powder. The CCF can be fabricated by the infiltration method. The influence of the thickness and the pore size of the copper foam and the mass fraction of doped Fe3O4 powder on the absorption bandwidth were investigated. When the thickness of the CCF is 1.5 mm, the pore size of the copper foam is 95 pores per inch (ppi), and the mass fraction of Fe3O4 is 1%; a broadband absorption is achieved in the range of 0.11-3.5 THz. It is noted that the mass fraction of Fe3O4 has a significant impact on the absorption bandwidth. In addition, the thickness of the CCF and the pore size of the copper foam also have an impact on the absorption. The impedance matching theory is introduced to understand the mechanism of broadband absorption. This flexible broadband absorber has potential application in terahertz stealth, shielding, and the sixth-generation (6G) broadband wireless communication in the future.

Electrooxidation of glycerol to formic acid coupled with Energy-Saving hydrogen production over ruthenium doped Cobalt-Based nanosheet arrays

The utilization of small molecule oxidation reactions as a substitute for the sluggish oxygen evolution reaction (OER) in traditional water electrolysis represents an innovative approach to achieve efficient hydrogen production while concurrently generating value-added chemicals. Herein, we report an energy-saving H2 production system utilizing electrooxidation of glycerol to generate valuable formate. Cobalt–ruthenium oxide nanosheet arrays (CoRuO/CF) and cobalt–ruthenium bimetallic nanoparticles wrapped by nitrogen-doped carbon nanosheet arrays (CoRuCN/CF) were synthesized for glycerol oxidation reaction (GOR) and hydrogen evolution reaction (HER), respectively, using Co-ZIF nanosheets precursor material supported on copper foam (Co-ZIF/CF) as the substrate. Remarkably, the hybrid electrolysis system can achieve a current density of 10 mA cm−2 with only 1.19 V, which is significantly lower than that required by traditional water-splitting systems. This work demonstrates the promising potential of efficiently utilizing biomass energy and achieving a sustainable production process for fine chemical products.

Synergistic effect of alcohol polyoxyethylene ether sodium sulphate and copper foam on methane hydrate formation

AbstractNatural gas is the cleanest fossil energy source and its consumption is increasing rapidly, so an efficient natural gas way of storing and transporting is urgently needed. Solidified natural gas (SNG) technology is gaining traction because of its higher safety, lower cost, and flexible storage and transportation modes. To improve the methane uptake rate in SNG technology, this work investigated the growth of methane hydrate in fatty alcohol polyoxyethylene ether sodium sulphate (AES) solution with the addition of three different pores per inch (PPI) of copper foam (CF). The results showed that the addition of AES caused the hydrate to grow upwards along the wall, and the methane uptake in the 300 ppm AES solution was increased by 623% compared to pure water. CF not only provided more nucleation sites for hydrate but also transferred the heat generated during hydration. Moreover, there was a synergistic effect between AES and CF and the solution could continuously transport upward along the continuous metal skeleton to increase the gas–liquid contact area. Thus, the formation rate and induction time of methane hydrate improve. Hydrate had the highest methane uptake in the 20 PPI CF system and the lower the pressure, the greater the ability of CF to promote hydrate formation. The methane uptake improved by 27.6% and the induction time was reduced by 59.7% compared to the pure AES system at 6 MPa. This work is aimed at advancing SNG technology (especially at low pressure) and informs the theoretical foundation.

Copper-Surface-Mediated Synthesis of sp2 Carbon-Conjugated Covalent Organic Framework Photocathodes for Photoelectrochemical Hydrogen Evolution.

Sp2-carbon (sp2-c) covalent organic frameworks (COFs), featuring distinctive π-conjugated network structures, facilitate the migration of photo-generated carriers, rendering them exceptionally appealing for applications in photoelectrochemical water splitting. However, owing to the powdery nature of COFs, leaving anchor the sp2-c COFs powder tightly onto a conductive substrate challenging. Here, we propose a method for preparing photoactive substance-conductive substrate integrated photocathodes through copper surface-mediated knoevenagel polycondensation (Cu-SMKP), this approach results in a uniform and stable sp2-c COF film, directly grown on commercial copper foam (COFTh-Cu). The COFTh-Cu demonstrates a high H2-evolution photocurrent density of 56 μA cm-2 at 0.3 V vs. RHE, sustaining stability for 12 h. The as-prepared COFTh-Cu represents a 4.5-fold increase in current density compared to traditional spin-coating methods and outperforms most COF photocathodes without cocatalysts. This innovative copper surface-mediated approach for preparing photocathodes opens up a crucial pathway towards the realization of highly active COF photocathodes.

Nitrate Reduction Catalyzed by Bimetallic Silver‐Copper Macroporous Foams

AbstractIn this work we describe the use of bimetallic silver‐copper macroporous foams for electrochemical nitrate reduction in acidic conditions (pH 2, 0.1 M NaClO4). By carefully selecting the composition of the electrodeposition bath, we have successfully prepared foams with atomic percentage varying from Ag dominant to Cu dominant. Also, we have succeeded to obtain morphologies that vary between the one specific to pure Ag foam to the one specific to pure Cu foam. We have shown that these foams contain a pure silver phase and also a silver‐copper alloy. The electrochemical active surface area of the foams depends both on the morphology as well as on the atomic composition. These materials were used for the first time as catalysts for nitrate electrochemical reaction (NO3RR). Both liquid and gaseous products were quantified with several analytical techniques. It was shown that bimetallic foams present superior faradaic efficiency (FE) towards liquid products in comparisons with pure silver and copper foams, suggesting a synergetic contribution from both metals. The Ag94Cu6 (AgCu10) foam shows a FE as high as 92 % towards liquid products and the lowest FE (3 %) towards the undesired product, i. e. nitrous acid. Also, this material shows a better stability than pure copper materials in the presence of nitrate in acidic conditions.

Insight into the efficient electrochemical reduction of nitrate employing Pd/Ru bimetallic doped copper foam cathode: Selectivity and reliability

Nitrate pollution threatens ecological environment and human health. Electrochemical reduction of nitrate to ammonia using metal-doped modified cathode is a promising technique for nitrate removal. In this work, a bimetallic Ru/Pd-doped Cu foam (CF) electrode was developed for nitrate reduction using cation exchange method. Confirmed by various physio-chemical characterization, it was found that the Ru/Pd-Cu Spongy Copper Foam (SCF) was successfully prepared. In addition, nearly 100 % nitrate removal, 94.07 % NH3 selectivity, and 84.9 % Faradaic efficiency (FE) could be achieved, under the optimized conditions as 100 mg L−1 of initial NO3--N concentration, 0.3 mol L−1 of Na2SO4 as electrolyte and the applied current of 5.42 mA cm−2. Through electrochemical testing and DFT calculation, it was revealed that the bimetallic doping of Ru/Pd facilitate electrocatalytic nitrate reduction reaction (NO3RR) by reducing the energy barriers of the NO3--to-NH3 pathway from 0.81 to 0.56 eV. Besides, the electrode showed excellent stability and anti-toxicity even after 10 repeated NO3RR cycles, since the NH3 yield rate and NH3 selectivity ranged from 0.206 to 0.231 mg h−1 cm−2, 87–96.87 % respectively. After NO3RR, an extended electrochemical oxidation process was implemented to remove ammonia, and nearly 100 % of NH3 was oxidized to N2 without byproducts. Thereby, this study provides a new option for the electrochemical reduction of nitrate to ammonia via cathode modification, to achieve the substantial nitrate removal from nitrate-containing water.

Three-dimensional gel network structure of agarose interlayer dispersed Pd nanoparticles in copper foam electrode for electrocatalytic degradation of doxycycline hydrochloride

In this study, we successfully prepared palladium/agarose/copper foam (Pd/AG/CF) composite electrodes by utilizing the three-dimensional network structure agarose (AG), a green material derived from biomass, and homogeneously immobilizing palladium (Pd) atoms on a copper foam (CF) substrate through a facile route. The electrode showed excellent performance in the electrocatalytic degradation of doxycycline (DOX), with a high DOX degradation rate of 92.19 % in 60 min. In-depth studies revealed that palladium can form metal-metal interactions with the CF substrates, which enhances the electron transfer on the catalyst surface. In addition, the introduction of agarose effectively prevented the agglomeration of palladium nanoparticles. In addition, the hydroxyl functional groups in the molecular structure of agarose facilitate interactions between water molecules and the electrode interface through the formation of hydrogen bonds, thereby further enhancing the efficiency of the electrocatalytic reaction. In addition to good stability and reusability. Microbial toxicity test results show that the degraded wastewater has minimal impact on the environment. Also, possible degradation pathways of DOX were explored in this study. Finally, a novel continuous flow reactor was designed, featuring a unique design that ensures full contact between wastewater and the composite electrodes, thereby achieving continuous and efficient treatment of antibiotic wastewater.

Well-dispersed NiFeS2@Cu2S heterojunction nanorods as high energy density electrode for supercapacitors

Transition metal sulfide heterostructures have demonstrated significant potential in enhancing the performance and cycling stability of supercapacitors due to their adjustable electronic structure. In this study, we synthesized an integrated electrode by constructing NiFeS2@Cu2S heterostructure nanorods onto a copper foam (CF) substrate. The heterostructure displays a crucial role in improving the electrochemical properties of the NiFeS2@Cu2S electrode, which exhibits a high specific capacity of 588 mAh g−1 at a current density of 1 A g−1. Moreover, The assembled CF@NiFeS2@Cu2S //CF@AC asymmetric supercapacitor (ASC) delivers an impressive energy density of 68.6 Wh kg−1 at a power density of 800 W kg−1. This work provides a novel strategy to design and construct highly efficient electrode materials for energy storage applications.

High‐Performance Pomegranate‐Like CuF2 Cathode Derived from Spent Lithium‐Ion Batteries

AbstractWith the large‐scale application of lithium‐ion batteries (LIBs), a huge amount of spent LIBs will be generated each year and how to realize their recycling and reuse in a clean and effective way poses a challenge to the society. In this work, using the electrolyte of spent LIBs as solvent, we in situ fluorinate the conductive three‐dimensional porous copper foam by a facile solvent‐thermal method and then coating it with a cross‐linked sodium alginate (SA) layer. Benefiting from the solid‐electrolyte interphase (SEI) that accommodating the volume change of internal CuF2 core and SA layer that inhibiting the dissolution of CuF2, the synthesized CuF2@void@SEI@SA cathode with a pomegranate‐like structure (yolk‐shell) exhibits a large reversible capacity of ~535 mAh g−1 at 0.05 A g−1 and superb cycling stability. This work conforms to the development concept of green environmental protection and comprehensively realizes the unity of environmental, social and economic benefits.

High-Performance Pomegranate-Like CuF2 Cathode Derived from Spent Lithium-Ion Batteries.

With the large-scale application of lithium-ion batteries (LIBs), a huge amount of spent LIBs will be generated each year and how to realize their recycling and reuse in a clean and effective way poses a challenge to the society. In this work, using the electrolyte of spent LIBs as solvent, we in situ fluorinate the conductive three-dimensional porous copper foam by a facile solvent-thermal method and then coating it with a cross-linked sodium alginate (SA) layer. Benefiting from the solid-electrolyte interphase (SEI) that accommodating the volume change of internal CuF2 core and SA layer that inhibiting the dissolution of CuF2, the synthesized CuF2@void@SEI@SA cathode with a pomegranate-like structure (yolk-shell) exhibits a large reversible capacity of ~535 mAh g-1 at 0.05 A g-1 and superb cycling stability. This work conforms to the development concept of green environmental protection and comprehensively realizes the unity of environmental, social and economic benefits.

Engineering of novel vanadium-doped Ni4N@CuCoN0.6 heterostructure for enhancing urea oxidation reaction at high current density

Herein, the vanadium-doped Ni4N@CuCoN0.6 heterostructure with brush shape structure supported on copper foam (denoted as V-doped-Ni4N@CuCoN0.6/CF) is prepared to serve as a highly-performing UOR electrocatalyst at high current density (E10/500/1000 = 1.26/1.40/1.45 V). Thanks to the construction of heterojunction, the local charge density undergoes redistribution at the V-doped-Ni4N@CuCoN0.6/CF interface in a 1.0 M KOH + 0.5 M urea solution, thereby significantly enriching the active site and facilitating the adsorption process of urea molecules. Notably, V doping exerts an additional influence by modulating the electronic structure of the catalyst, potentially optimizing the urea adsorption/CO2 desorption process and reducing the energy barrier for the rate-determining step. Operando electrochemical impedance spectroscopy results show direct oxidation for urea molecules on the surface of V-doped-Ni4N@CuCoN0.6/CF, indicating that V-doping and heterostructure can effectively improve electron transfer. Furthermore, because the brush shape structure can be beneficial for bubble release and liquid transport on the catalyst’s surface, for UOR stability, V-Ni4N@CuCoN0.6/CF can maintain at 500 mA cm−2 for 80 h.

Study of three-dimensional spatial diffuse discharge in contact electrode structure applied to air purification

In this work, based on the role of pre-ionization of the non-uniform electric field and its effect of reducing the collisional ionization coefficient, a diffuse dielectric barrier discharge plasma is formed in the open space outside the electrode structure at a lower voltage by constructing a three-dimensional non-uniform spatial electric field using a contact electrode structure. The air purification study is also carried out. Firstly, a contact electrode structure is constructed using a three-dimensional wire electrode. The distribution characteristics of the spatial electric field formed by this electrode structure are analyzed, and the effects of the non-uniform electric field and the different angles of the vertical wire on the generation of three-dimensional spatial diffuse discharge are investigated. Secondly, the copper foam contact electrode structure is constructed using copper foam material, and the effects of different mesh sizes on the electric field distribution are analyzed. The results show that as the mesh size of the copper foam becomes larger, a strong electric field region exists not only on the surface of the insulating layer, but also on the surface of the vertical wires inside the copper foam, i.e., the strong electric field region shows a three-dimensional distribution. Besides, as the mesh size increases, the area of the vertical strong electric field also increases. However, the electric field strength on the surface of the insulating layer gradually decreases. Therefore, the appropriate mesh size can effectively increase the discharge area, which is conducive to improving the air purification efficiency. Finally, a highly permeable stacked electrode structure of multilayer wire-copper foam is designed. In combination with an ozone treatment catalyst, an air purification device is fabricated, and the air purification experiment is carried out.

Active and hybrid battery thermal management system using microchannels, and phase change materials for efficient energy storage

Efficient battery thermal management (BTM) is key to the safety and performance of Lithium-ion batteries. This study focuses on cooling a module of 15 prismatic Lithium-titanate cells at an 8C discharge rate using finite volume numerical modeling. Initially, the impact of Reynolds numbers and microchannel count on temperature is examined. Then, Phase change materials (PCM) are introduced to increase thermal management efficiency. Three cases for optimizing the hybrid-BTM system are compared: nanoparticles (1%–5% volume fraction), copper foam (93 % porosity), and micro-encapsulated PCM slurry (5%–15 % volume fraction). The results indicate that an increase in microchannels improves the performance evaluation criterion (PEC) by 93.1 %. Additionally, using copper foam increases the PEC by 18.43 %, 17.44 %, 16.53 %, and 16.31 % at Reynolds numbers 800, 1200, 1600, and 2000, respectively. Furthermore, the BTM system using 5 % nanoparticles demonstrates the best performance, reducing the module temperature by 2.41 % in the presence of copper foam and by 1.78 % in the pure state. Moreover, while the MPCM slurry effectively reduces the module temperature to a desirable level, the high pumping costs significantly decrease the PEC. Additionally, the total entropy of the BTM system follows frictional entropy, although thermal entropy effects dominate the PCM.

Sunlight-promoted CO2 electroreduction with staggered p-n heterojunction by indium-doped bismuth 3D nanoflower structure on oxidized copper foam as self-standing photoelectric cathode over a wide potential window

Exploiting suitable photocathodes to achieve high photocurrent and long-term endurance is still a great challenge in photoelectrocatalytic CO2 reduction (PEC CO2) reactions. Herein, an In-doped Bi2O3 decorated oxidized copper foam (CBIO/CF) self-standing photoelectric cathode is well designed by the self-assembly process without an externally added binder. Via sunlight-promoted strategy, CBIO/CF with a unique 3D hierarchical nanoflower structure displays a superior faradaic efficiency of 90.0 % towards HCOOH over a wide potential window from −0.87 ∼ −1.17 VRHE and reaches 97.8 % at −0.87 VRHE with a partial current density of 14.41 mA cm−2. The in-situ Fourier transform infrared spectroscopy (FTIR) analysis demonstrates the abundant oxygen defects induced by In doping boost CBIO/CF absorbing substantive intermediate species related with formate generations, and porous structure accelerating mass transportation. Moreover, the well-designed staggered p-n heterojunctions of Cu2O and In-doped Bi2O3 on the surface of catalysts favor the generation and separation of electron/hole pairs and contribute to the photocatalytic reduction of CO2 under a bias voltage. This work paves the way for rational regulation of self-supporting photoelectrode for PEC CO2 to HCOOH with suitable conduction band valence bands and high performance and stability.