Porous Copper Research Articles

Selective Electrochemical CO2 Reduction to Ethylene and Multi-carbon Products on Oxide-derived Porous CuO Micro-cages

The electrochemical reduction of CO2 (CO2RR) presents a dual benefit: it helps mitigate environmental pollution while producing valuable multi-carbon (C2+) chemicals and storing renewable energy in chemical fuels. However, there is an urgent need for efficient electrocatalysts that can selectively increase the production of ethylene and C2+ products for the wide-scale implementation of CO2RR. Herein, we have facilely synthesized porous micro-caged oxide-derived copper oxide (OD-Cu MC) using a one-pot hydrothermal approach followed by air-annealing at 350 °C. The resulting electrocatalyst exhibited excellent performance for ethylene (C2H4) production, achieving a faradaic efficiency (FE) of 44.8 % for C2H4 and cumulative FE of 73.1 % for C2+ products at current density (ID) of 300 mA cm−2. At an ID of 400 mA cm−2, OD-Cu MC demonstrated a turnover frequency (TOF) of 0.012 s−1 for ethylene, which is 7.8 times higher than the TOF observed for commercially available copper oxide (CuO-CM). Moreover, at an ID of 300 mA cm−2, OD-Cu MC achieved a single-pass CO2 conversion (SPCC) of 35.2 % and a half-cell energy efficiency of 15.6 % for C2+ products. The catalyst also showed good stability, maintaining its performance for over 4 h at an ID of 200 mA cm−2. This straightforward synthesis approach opens new avenues for enhancing C2+ product selectivity in CO2RR.

Synergistic uranium extraction, organic degradation, and electricity generation by a self-driven photoelectrochemical system with TNR/Si PVC photoanode and copper foam cathode

Herein, we develop a self-driven photoelectrochemical system (SDPS) featuring a TiO2 nanorod array (TNR)/Si photovoltaic cell (Si PVC) photoanode and a porous copper foam (CF) cathode for efficient uranium recovery. Under simulated sunlight illumination, this SDPS simultaneously achieves ∼ 99.4 % UO22+ recovery and ∼ 99.2 % sulfamethoxazole (SMX) removal, with observed rate constant (kobs) value of 0.121 min−1 and 0.029 min−1, respectively, and a maximum power density (Pmax) of 0.89 mW·cm−2 when treating complex wastewater of SMX (10 mg·L−1)-UO22+ (10 mg·L−1). The TNR photoanode absorbs short-wavelength light (λ < 412 nm), generating electron-hole pairs, while the rear Si PVC absorbs transmission light, creating a self-bias potential that drives electrons transfer towards CF cathode, continuously generating electrical energy in the external circuit. The retained holes and derived •OH oxidize SMX, breaking UO22+-SMX complexation, while electrons on the CF reduce UO22+ to insoluble tetravalent uranium (U(IV)) species. This SDPS demonstrates robust performance across varying UO22+ (5 ∼ 40 mg·L−1) and SMX (0 ∼ 40 mg·L−1) concentrations, pH ranges (4 ∼ 8), coexisting ions, and different types of uranium-containing wastewaters, maintaining stability over 20 cycles. It achieves ∼ 97.5 % UO22+ extraction and ∼ 99.8 % SMX removal in simulated seawater, with a Pmax of 1.27 mW·cm−2. This work presents a promising resource strategy for uranium extraction.

Vapor separation in minichannel heat sink flow boiling application using gradient porous copper ribs

Vapor separation in minichannel heat sink flow boiling application using gradient porous copper ribs

The Effect of Process Parameters on the Pore Structure of Lotus-Type Porous Copper Fabricated via Continuous Casting

The pores in lotus-type porous copper are formed due to the difference in hydrogen solubility between the liquid and solid phases of copper. In a pressurized hydrogen atmosphere, hydrogen gas is released at the gas release and crystallization temperature, which is the melting point of copper. This study systematically analyzes the effects of process parameters, including hydrogen ratio, total pressure, and continuous casting speed, on the pore structure of lotus-type porous copper, with the aim of identifying the most critical process parameters for controlling pore diameter and density. Within the hydrogen ratio up to 50%, it was observed that as the hydrogen ratio increases, the pores tend to increase in porosity, and the pore diameter increases. As the hydrogen ratio increased from 25% to 50%, the pore diameter increased from 300 μm to 400 μm, while the pore density decreased from 3.3 N·mm−2 to 2.8 N·mm−2. As the total pressure increased, the pore diameter tended to decrease, and the pore density increased. Specifically, when the total pressure increased from 0.2 MPa to 0.4 MPa, the pore diameter decreased from 1100 μm to 400 μm, while the pore density increased significantly from 0.5 N·mm−2 to 2.8 N·mm−2. In addition, as the continuous casting speed increased, 30 to 90 mm·min−1, the pore diameter decreased from 850 μm to 400 μm, and the pore density increased from 0.7 N·mm−2 to 2.8. N·mm−2. Specifically, the increase in total pressure led to a decrease in Gibbs free energy and a reduction in the critical pore nucleation radius, which promoted pore formation and resulted in the creation of more, smaller pores. These results suggest that total pressure is the primary factor influencing both pore diameter and density in lotus-type porous copper.

Investigating the photocatalytic efficacy of a porous cuprous gallate (CuGa2O4) thick film

Abstract The study aimed to investigate the photocatalytic activity of porous copper gallate (CuGa2O4) thick film with significant wall dimensions. The thick film was meticulously fabricated using tape casting systems, with CuGa2O4 nanoparticles synthesized by Sol–Gel technique and subsequently transformed into gels for the tape casting process. Rietveld refinements were employed to elucidate the crystal structure and lattice parameters of the CuGa2O4 spinel oxide lattice. Moreover, electronic energy configurations and optical transmittance measurements were acquired through UV-visible spectrophotometry. The correlations between the crystal structure, band gap change and formation of electronic energy levels in relation to the photocatalytic performance of CuGa2O4 were explored. The comprehensive examination provides valuable insights into the complex interaction between material properties and photocatalytic behavior, offering a nuanced understanding of the potential applications of porous CuGa2O4 thick films in various technological fields.

Study on Oxygen Plasma-Based Copper Etching Process

Abstract A plasma-based, room-temperature copper etch process using the chlorine- or bromine-containing feed gas was reported. This simple process could potentially replace the chemical mechanical polishing method in preparing copper interconnects. However, the chlorine- and bromine-containing gases are corrosive and must be handled with expensive equipment following stringent safety procedures. In this paper, the oxygen plasma-based copper etch process is presented. The copper film was converted into a porous and polycrystalline copper oxide film which was subsequently dissolved in a dilute hydrochloric acid solution. The copper film was expanded when converted into an oxide film. The oxidation precursors, i.e., oxygen radicals and ions, were generated in the plasma phase and then transported through the oxide layer to the underneath copper film where the oxidation reaction proceeded. The oxide growth rate is affected by plasma parameters, such as pressure and power, and the kinetics of the oxidation reaction. This new oxygen plasma-based process is a simple solution for preparing copper interconnects for nano and microelectronic products.

Optimizing the Pore Structure of Lotus-Type Porous Copper Fabricated by Continuous Casting.

Lotus-type porous copper was fabricated using a continuous casting method in pressurized hydrogen and nitrogen gas atmospheres. This study evaluates the effects of process parameters, such as the hydrogen ratio, total pressure, and transference velocity, on the resulting pore structure. A continuous casting process was developed to facilitate the mass production of lotus-type porous copper. To achieve the desired porosity and pore diameter for large-scale manufacturing, a systematic evaluation of the influence of each process parameter was conducted. Lotus-type porous copper was produced within a hydrogen ratio range of 25-50%, a transference velocity range of 30-90 mm∙min-1, and a total pressure range of 0.2-0.4 MPa. As a result, the porosity ranged from 36% to 55% and the pore size varied from 300 to 1500 µm, demonstrating a wide range of porosities and pore sizes. Through process optimization, it is possible to control the porosity and pore size. The hydrogen ratio and total pressure were found to primarily affect porosity, whereas the hydrogen ratio, transference velocity, and total pressure significantly influenced pore diameter. When considering these parameters together, porosity was most influenced by the hydrogen ratio, whereas the total pressure and transference velocity had a greater influence on pore diameter. Reducing the hydrogen ratio and increasing the transference velocity and total pressure reduced the pore diameter and porosity. This optimization of the continuous casting process enables the control of porosity and pore diameter, facilitating the production of lotus-type porous copper with the desired pore structures.

Construction of 0-dimensional silver quantum dot/MoSe2@MXene/3-dimensional porous copper foam composite electrodes with heterogeneous interfaces for synergistic electrocatalytic degradation of antibiotics

This study proposes a novel and efficient Ag quantum dots (QDs)/MoSe2@two-dimensional transition metal carbide/nitride (MXene)/copper foam (CF) composite electrode to address the challenge of electrocatalytic degradation of antibiotics in water. The electrode formed a unique electron donor–acceptor system by loading Ag QDs and heterostructured nanosheets on CF, significantly facilitating charge transfer and segregation at the interface. The catalytically active sites at the edges and defective locations of MoSe2 in conjunction with the two-dimensional MXene structure, which formed an efficient electron transfer channel, promoted the electron transfer from the interior to the surface and accelerated the hydrogen adsorption and reduction reactions. Moreover, the charge redistribution at the interface of Ag QDs and MoSe2@MXene formed interfacial dipoles, increasing the active sites on the catalyst surface and promoting the generation of cathodic atomic hydrogen (H*). Under optimal conditions, the degradation rate of tigecycline (TGC) reached as high as 90.1 % ± 2.4 % within 60 min. The anode-generated OH and HClO, along with the cathode-generated H, further promoted the degradation of TGC through co-catalysis. The degradation pathways were analyzed using density-functional theory (DFT) calculations and liquid chromatography-mass spectrometry (LC-MS) techniques. Moreover, toxicity analysis of the degradation products was carried out to ensure the safety of the treated wastewater discharge. A reflux continuous effluent reactor was also designed to achieve high degradation efficiency and low energy consumption after stable operation, laying the foundation for industrial applications. This technology provides new ideas for the design of green, efficient, stable, and low-consumption electrocatalytic reactors and contributes to a sustainable future environment.

Potential difference-induced electrodeposition of defect-rich α-cobalt hydroxide on porous copper (PCu): High-voltage performance of supercapacitor

Designing electrode materials for aqueous battery-type supercapacitors to extend the operating voltage window remains a significant challenge to increase the energy density of aqueous supercapacitors. In this work, a directional electrodeposition method without any additives was employed to deposit α-Co(OH)2 onto a porous copper (PCu) current collector substrate, which involves the fabrication of a supercapacitor electrode material with a cross-linked network structure named α-Co(OH)2@PCu900. The potential difference between copper and cobalt facilitated the formation of a larger interlayer spacing for α-Co(OH)2. In addition, crystals of α-Co(OH)2 with different orientations exert stress on one another, leading to lattice distortion and vacancy formation. The morphology and microstructure of materials were analyzed through techniques such as SEM, HRTEM, XRD, and XPS, confirming the validity of the experimental design. This defect-rich, large interlayer spacing structure facilitates ion intercalation and deintercalation during the charge-discharge process, thereby expanding the operating voltage window. In a three-electrode system, α-Co(OH)2@PCu900 exhibited a potential range from −0.45 V to 0.55 V and demonstrated an areal capacitance of 2580 mF cm−2 and specific capacitance of 600 A g−1 at 2 mA cm−2. The α-Co(OH)2@PCu900 was used as the cathode material and commercial reduced graphene oxide (rGO) was used as the anode material in an asymmetric supercapacitor, and the ASC device exhibited an areal capacitance of 295.3 mF cm−2 and a specific capacitance of 87.89 F g−1. Notably, it retained a high energy density of 0.12 mW h cm−2 (35.27 Wh kg−1) at a power density of 1.7 mW cm−2 (505.95 W kg−1). This method established α-Co(OH)2@PCu900 as a promising supercapacitor electrode material, providing a viable strategy for designing and fabricating functional electrode materials.

Development of a processing route for the fabrication of thin hierarchically porous copper self-standing structure using direct ink writing and sintering for electrochemical energy storage application

Development of a processing route for the fabrication of thin hierarchically porous copper self-standing structure using direct ink writing and sintering for electrochemical energy storage application

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.

Functionalization of a porous copper(ii) metal-organic framework and its capacity for loading and delivery of ibuprofen.

A porous copper(ii) metal-organic framework (MOF) of 4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine(N3ttb) and 5-nitroisophthalic acid (npd) formulated as [Cu(npd)(N3ttb)]·(DMF)(H2O) 1 (DMF = dimethylformamide) was synthesized and characterized by elemental analyses, spectroscopic techniques, single crystal X-ray crystallography, and scanning electron microscopy. Single crystal X-ray crystallographic analysis of the copper(ii) metal-organic framework reveals a monoclinic crystal system with space group P21/c. The copper(ii) ion is in a five-coordinate geometry consisting of three meridional nitrogen atoms of 4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine and two oxygen atoms of 5-nitroisophthalic acid to form a square pyramidal structure. The compound was functionalized with ethylenediamine (ED) to form [Cu(npd)(N3ttb)]-ED 2 that was characterized by FT-IR, PXRD, SEM-EDX and BET and the drug loading capacity was investigated and compared with that of as-synthesized MOFs. The amount of ibuprofen loaded was 916.44 mg g-1 (15.27%) & 1530.20 mg g-1 (25.50%) over 1 and 2, respectively. The results indicate that the functionalized MOFs 2 have a higher loading capacity for ibuprofen than 1 by 613.76 mg g-1 (10.23%), which could be ascribed to the acid-base interactions in the functionalized molecules. The results show that [Cu(npd)(N3ttb)]-ED 2 is a better drug transporter than [Cu(npd)(N3ttb)]·(DMF)(H2O) 1 due to the presence of an amine functional group that interacts with the acid group on the ibuprofen through non-covalent bonds interactions.

Homogenized Modeling of CO2/CO Reduction Catalyst Microenvironments with Intermixed Hydrophobic and Hydrophilic Regions

Electroreduction of CO and CO2 offer a pathway toward renewable-powered synthesis of hydrocarbon chemicals and fuels. Both the composition and the structure of cathodic catalyst microenvironments in gas diffusion electrodes play a dominant role in determining the product composition and efficiency metrics. Porous and hydrophilic copper environments are known to produce multi-carbon species and exhibit large active surface areas, but recent investigations have shown that the inclusion of sporadically-distributed porous hydrophobic regions creates additional pathways for the delivery of gaseous reactants, thereby mitigating transport limitations seen in pure Cu catalysts.As the design space for catalysts has grown to include a wide variety of material and geometric parameters, accurate PDE-based modeling and simulation of such systems has become necessary to understand and optimize the coupled reaction and transport processes that determine cell performance. High fidelity models, however, pose immense computational challenges. Physical and chemical processes occur over a wide variety of spatiotemporal scales, ranging from pore-scale reaction and transport to device-scale gradients in species concentrations. Additionally, the spatial orientation of these features necessitates modeling in multiple dimensions, and transport occurs simultaneously through two phases located within randomly-intermixed porous regions. As a result of all these factors, numerical simulation of high fidelity models is prohibitively expensive.In this work, we develop, numerically simulate, and validate a predictive model that efficiently incorporates a wide range of physical and chemical processes occurring in catalyst microenvironments with intermixed hydrophobic and hydrophilic regions. We employ homogenization as a means of model reduction, constructing a medium fidelity model that captures both microenvironment geometric scales and full device scales in 3D. Our model, coupled with the appropriate numerical methods for treatment of stiff and multi-dimensional problems, permits low-cost exploration of the high-dimensional parameter space associated with recently developed catalysts, offering quantitative insight into the optimal design of microenvironments for CO and CO2 electroreduction.This work is supported by the United States Department of Energy under grant DE-SC0021633.

Reduction of Air Pollution from IC Engine Exhausts Through Condensation with Novel Porous Copper Metal Foams

Reduction of Air Pollution from IC Engine Exhausts Through Condensation with Novel Porous Copper Metal Foams

A Dendrite-Free Lithium Metal Battery by Incorporating Poly(dimethylsiloxane) Layer onto the Porous Three-Dimensional Copper Current Collector

A Dendrite-Free Lithium Metal Battery by Incorporating Poly(dimethylsiloxane) Layer onto the Porous Three-Dimensional Copper Current Collector

Microstructural Investigation of Porous Plating Copper by Atom Probe Tomography

Microstructural Investigation of Porous Plating Copper by Atom Probe Tomography

Electro-synthesis of valuable products by coupling energy-saving anodic alcohol oxidation reaction with cathodic CO2 reduction reaction

Electrocatalytic carbon dioxide reduction reaction (CO2RR) offers a promising pathway towards achieving carbon neutrality. However, its efficiency is hindered by the sluggish oxygen evolution reaction (OER) at the anode, which consumes a significant portion of the energy input. Herein, we report an effective strategy to replace OER with energy efficient alcohol oxidation reactions to produce value-added products at both cathode and anode of the electrolyzer. In an integrated cell, CO2RR is carried out at cathode using tin oxide deposited on porous copper (SnOx@pCu@CF) as an electrocatalyst while alcohol oxidation reactions (methanol, ethanol, benzyl alcohol) are conducted on porous copper (pCu@CF) anode in alkaline electrolyte. Over 89% selectivity for the cathodic reduction of CO2 into formate and almost 100% selectivity for anodic oxidation of methanol to formate, ethanol to acetate and benzyl alcohol to benzoate are achieved at high current densities within a wide potential range. The SnOx@pCu@CF//pCu@CF two-electrode arrangement required 100 mV less potential for the overall methanol-assisted CO2RR as compared to water oxidation assisted CO2RR with simultaneous production of valuable formate at both anode and cathode This study underscores the potential of coupling CO2RR with viable alternative oxidation reactions as a theoretically and technically feasible approach as well as holds significant promise for delivering substantial economic benefits.

Surface modification prepared porous copper oxide/(Cu-S)n metal-organic framework/reduced graphene oxide hierarchical structure for highly selective electrochemical quercetin detection.

Electrochemical alkalization of (Cu-S)n metal-organic framework (MOF) and graphene oxide ((Cu-S)n MOF/GO) composite yields a new CuO/(Cu-S)n MOF/RGO (reduced GO) composite with porous morphology on screen printed carbon electrode (SPCE) which facilitated the electron transfer properties in electrochemical quercetin (QUE) detection. A selective QUE detection ability has been demonstrated by the constructed electrochemical sensor (CuO/(Cu-S)n MOF/RGO/SPCE), which also has a broad dynamic range of 0.5 to 115µM in pH 3 by differential pulse voltammetry. The detection limit is 0.083µM (S/N = 3). In this study, it was observed that the real samples contained 0.34mgmL-1 and 27.7µgg-1 QUE in wine and onion, respectively.

Electroless copper plating of 3D-printed polymer foam: A promising method to fabricate electrodes for denitrification

This work involves processing porous copper structures through electroless plating/metallization on 3D-printed polymer foam (PF) and exploiting them as electrode material for denitrification studies. A sustainable electroless plating process using KOH and H2SO4 for etching and copper seed crystals for surface activation is presented as an alternative to conventional chromic acid and palladium. This etching process increased average surface roughness (Ra) from 58.7 to 287 nm and amplification of hydrophilic functional groups. These modifications enhance the surface’s wettability by reducing the contact angle from 96.35 to 37.5°, thereby facilitating uniform deposition. After activation, Cu deposition was accomplished by immersing the foam in the bath. The resulting Cu-metallized polymer foams (Cu/PF) were investigated as electrodes for nitrate reduction, showing a sensitivity of 5.86 mA/mM within a nitrate concentration range of 2.5–10 mM, also demonstrated good stability in durability tests.