Articoli di riviste: "Cu foam"

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Wang, Jing, Zan Zhang, Jian Ding, Chuan Rong Qiu, Xing Chuan Xia e Wei Min Zhao. "Quasi-Static Compressive Characteristics of Cu-Containing Closed-Cell Aluminum Foams". Key Engineering Materials 748 (agosto 2017): 173–80. http://dx.doi.org/10.4028/www.scientific.net/kem.748.173.

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Closed-cell aluminum foam with different percentages of Cu was prepared by melt foaming method.The effect of Cu element on the quasi-static compressive properties of aluminum foam was investigated, both under as-cast and heat-treated conditions. The results showed that Cu element distributed in cell wall matrix mainly in the forms of Al-Cu solid solutions and AlCu3, Al6.1Cu1.2Ti2.7 intermetallics. Meanwhile, Cu-containing foams possessed much higher compressive strength than the commercially pure aluminum foams. Additionally, proper heat treatment could further improve the yield strength of Cu-containing foams and the effect of aging treatment was more obvious than the homogenizing heat treatment under the present conditions and the reasons were discussed.

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Dutta, Abhijit, Kiran Kiran, Motiar Rahaman, Ivan Zelocualtecatl Montiel, Pavel Moreno-Garcí, Soma Vesztergom, Jakub Drnec, Mehtap Oezaslan e Peter Broekmann. "Insights from Operando and Identical Location (IL) Techniques on the Activation of Electrocatalysts for the Conversion of CO2: A Mini-Review". CHIMIA International Journal for Chemistry 75, n. 9 (15 settembre 2021): 733–43. http://dx.doi.org/10.2533/chimia.2021.733.

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In this mini-review we compare two prototypical metal foam electrocatalysts applied to the transformation of CO2 into value-added products (e.g. alcohols on Cu foams and formate on Bi foams). A substantial improvement in the catalyst performance is typically achieved through thermal annealing of the as-deposited foam materials, followed by the electro-reduction of the pre-formed oxidic precursors prior or during the actual CO2 electrolysis. Utilizing highly insightful and sensitive complementary operando analytical techniques (XAS, XRD, and Raman spectroscopy) we demonstrate that this catalyst pre-activation process is entirely accomplished in case of the oxidized Cu foams prior to the formation of hydrocarbons and alcohols from the CO2. The actually active catalyst is therefore the metallic Cu derived from the precursor by means of oxide electro-reduction. Conversely, in their oxidic form, the Cu-based foam catalysts are inactive towards the CO2 reduction reaction (denoted ec-CO2 RR). Oxidized Bi foams can be regarded as an excellent counter example to the above-mentioned Cu case as both metallic and the thermally derived oxidic Bi foams are highly active towards ec-CO2 RR (formate production). Indeed, operando Raman spectroscopy reveals that CO2 electrolysis occurs upon its embedment into the oxidic Bi2O3 foam precursor, which itself undergoes partial transformation into an active sub-carbonate phase. The potential-dependent transition of sub-carbonates/oxides into the corresponding metallic Bi foam dictates the characteristic changes of the ec-CO2 RR pathway. Identical location (IL) microscopic inspection of the catalyst materials, e.g. by means of scanning electron microscopy, demonstrates substantial morphological alterations on the nm length scale on the material surface as consequence of the sub-carbonate formation and the potential-driven oxide reduction into the metallic Bi foam. The foam morphology on a mesoscopic length scale (macroporosity) remains, by contrast, fully unaffected by these phase transitions.

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Yang, Haobo, Jichao Li, Hao Yu, Feng Peng e Hongjuan Wang. "Metal-Foam-Supported Pd/Al2O3 Catalysts for Catalytic Combustion of Methane: Effect of Interaction between Support and Catalyst". International Journal of Chemical Reactor Engineering 13, n. 1 (1 marzo 2015): 83–93. http://dx.doi.org/10.1515/ijcre-2014-0009.

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Abstract Structured Pd/Al2O3 catalysts were fabricated by impregnating Pd onto Ni and Cu foams coated with Al2O3 layers. By testing the adhesion stability and catalytic activity in the combustion of methane, the superior performance of Ni-foam-supported Pd/Al2O3 catalyst was demonstrated, to its counterpart powder catalysts. The resultant structured catalysts enable the fabrication of lamellar microreactor systems. It is found that the metal foams influence the activity of catalyst layer, due to the diffusive penetration of metallic atoms into catalysts from metal foams. The Ni foam is beneficial for enhancing the activity of Pd/Al2O3 catalyst, while the Cu foam plays a negative role. The investigation to the model powder catalysts doped with Ni and Cu verified the modification of Ni and Cu to the physicochemical properties of Pd/Al2O3 catalyst, thereby the catalytic performances. Thus, it can be expected that the performance of structured catalysts may be improved by rationally designing and selecting proper supports.

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Sridaeng, Duangruthai, Benjatham Sukkaneewat, Nuttawut Chueasakol e Nuanphun Chantarasiri. "Copper-amine complex solution as a low-emission catalyst for flexible polyurethane foam preparation". e-Polymers 15, n. 2 (1 marzo 2015): 119–26. http://dx.doi.org/10.1515/epoly-2014-0197.

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AbstractA low-emission catalyst for the preparation of flexible polyurethane (FPUR) foams was developed. Copper-amine complex solutions in ethylene glycol (EG), namely, Cu(OAc)2(en)2-EG and Cu(OAc)2(trien)-EG (en, ethylenediamine; trien, triethylenetetramine), were synthesized and used as catalysts for the preparation of FPUR foams. The synthesis of Cu(OAc)2(en)2-EG and Cu(OAc)2(trien)-EG is convenient because the synthesis of copper-amine complexes can be done in situ using ethylene glycol as a solvent and no purification step is needed. It was found that Cu(OAc)2(en)2-EG was a suitable catalyst for FPUR foam preparation. In comparison to Dabco EG (or triethylenediamine), which is a commercial catalyst for FPUR foam preparation, Cu(OAc)2(en)2-EG had a comparable catalytic activity in gelling reaction and a higher catalytic activity in blowing reaction. The FPUR foam prepared from Cu(OAc)2(en)2-EG had a lower density than that prepared from Dabco EG.

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Huang, Yao, Zexin Li, Lucai Wang, Leilei Sun, Xiaohong You, Wenzhan Huang e Fang Wang. "Preparation and Heat Dissipation Properties Comparison of Al and Cu Foam". Metals 12, n. 12 (30 novembre 2022): 2066. http://dx.doi.org/10.3390/met12122066.

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The space holder method, a kind of powder metallurgy method which can avoid the process of melting metal to prepare metal foams, has particular significance in solving the difficulty of preparing metal foams with high melting points. In this paper, Na2S2O3·5H2O, a novel space holder, was used to prepare aluminium foam and copper foam, which were then used to test the heat dissipation performance of the metal foams. We first prepared two kinds of cell structures for (spherical cell and composite cells) aluminium and copper foam, then, we compared the performances of their heat dissipation, and it was found that both the spherical cell metal foam and composite cell metal foam promoted heat dissipation in the environment of natural convection, and the difference between them was not apparent. In the environment of forced convection, the composite porous metal showed a better heat dissipation performance.

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Mirzaee, Majid, e Changiz Dehghanian. "Nanostructured Ni-Cu Foam Electrodeposited on a Copper Substrate Applied as Supercapacitor Electrode". Acta Metallurgica Slovaca 24, n. 4 (11 dicembre 2018): 325. http://dx.doi.org/10.12776/ams.v24i4.1138.

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The applicability of nickel-copper metallic foams as a current collector was investigated for supercapacitor. A comprehensive characterization of Ni-Cu based foam was studied and the analysis of their structural, chemical, and electrochemical properties was evaluated. Structural characteristics and electrochemical methods were used to examine the surface morphology, and surface-chemical composition of the materials. The foams deposited at the time deposition of 180s exhibited dual-porosities (macro and mesopores) with pores ranging from13 to16 μm and the branch size ranged from 25 to 50 nm. Ni-Cu foam electrodes are employed as current collector for supercapacitor. Their usefulness as current collector was evaluated by well-defined experimental conditions using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge and discharge (GCD) techniques. The outcome of these experiments demonstrated that the Ni-Cu foams which was synthesized at the time deposition of 180s had pseudocapacitive behavior. The best value for specific capacitance which was calculated from GCD was (536 F/g at 1 mA/cm2) for the Ni-Cu foams deposited at 2 A/cm2 for 180 s. The Ni-Cu foam sustained a current density of 15 mA/cm2 after 2000 cycles without significant loss of supercapacitor activity.

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Sridaeng, Duangruthai, Wannisa Jitaree, Preecha Thiampanya e Nuanphun Chantarasiri. "Preparation of rigid polyurethane foams using low-emission catalysts derived from metal acetates and ethanolamine". e-Polymers 16, n. 4 (1 luglio 2016): 265–75. http://dx.doi.org/10.1515/epoly-2016-0021.

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AbstractTwo metal acetate-ethanolamine complexes, namely Cu(OAc)2(EA) and Zn(OAc)2(EA), were synthesized from metal acetates [M(OAc)2, where M=Cu and Zn] and ethanolamine (EA). These metal acetate-ethanolamine complexes can be used as catalysts in the preparation of rigid polyurethane (RPUR) foams. Both Cu(OAc)2(EA) and Zn(OAc)2(EA) were obtained as viscous liquids, which have very weak odor and could be easily dissolved in the starting materials of RPUR foam formulation. The results were compared with RPUR foam prepared from dimethylcyclohexylamine (DMCHA), which is a commercial catalyst with very strong amine odor. Considering the gel time and rise time, Cu(OAc)2(EA) had higher catalytic activity than Zn(OAc)2(EA) and both metal acetate-ethanolamine complexes had lower catalytic activity than DMCHA. Density and compressive strength of RPUR foam catalyzed by Cu(OAc)2(EA) were comparable to that prepared from DMCHA.

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Balciunaite, Aldona, Žana Činčienė, Loreta Tamasiunaite, Jūratė Vaičiūnienė e Eugenijus Norkus. "3D Structured Pt(Cu-Ni)/Ti Catalysts for the Oxidation of Sodium Borohydride". ECS Meeting Abstracts MA2022-01, n. 35 (7 luglio 2022): 1523. http://dx.doi.org/10.1149/ma2022-01351523mtgabs.

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Currently, one of the renewable energy sources is fuel cells, namely chemical energy is directly converted into electricity. Designing new or enhancing the existing fuel cells, much attention is devoted to the search of new effective catalysts, which would allow increasing the effectiveness of fuel cells and creating the background for designing new technologies for catalysts formation. The aim of the work is to form efficient and inexpensive nanostructured catalysts by electroplating 3D structure metal copper-nickel (Cu-Ni) foams on titanium (Ti) surface and decorating them with low amounts of platinum nanoparticles (PtNP) for the electrooxidation of sodium borohydride (NaBH4). The Cu-Ni foam was prepared by electrochemical deposition (I deposition=1.5 Acm-2, t deposition= 3,6 and 9 min) on Ti surface. The electrolyte contained 0.5 M Ni2+ ions, and the concentrations of Cu2+ ions ranged from 0.01 to 0.02 M. PtNP particles were deposited on Cu-Ni foam (noted (Pt(Cu-Ni)/Ti)) by immersion of Cu-Ni foam into 1 mM H2PtCl6 solution at 25 °C for 1 minute. The morphology and composition of the prepared catalysts were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and inductively coupled plasma optical emission spectroscopy (ICP-OES). The electrocatalytic activity of the 3D catalysts was evaluated towards the oxidation of borohydride by cyclic voltammetry method in 0.05 M NaBH4 solution in an alkaline media in the potential range from -1.2 to 0.6 V (vs. Ag/AgCl) and with an electrode potential scan rate of 10 mVs-1. The study showed that the prepared 3D Cu-Ni foam and Pt(Cu-Ni)/Ti have good electrochemical stability in alkaline NaBH4 solution. It was also observed that immersion of Cu-Ni foam in a platinum-containing solution for 1 min increased the electrocatalytic activity of the prepared Pt(Cu-Ni)/Ti catalysts for NaBH4 oxidation compared to Cu-Ni foam. Acknowledgment This project has received funding from European Social Fund (project No 09.3.3-LMT-K-712-19-0138) under a grant agreement with the Research Council of Lithuania (LMTLT).

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Ye, Bora, e Sunjung Kim. "Formation of Nanocrystalline Surface of Cu–Sn Alloy Foam Electrochemically Produced for Li-Ion Battery Electrode". Journal of Nanoscience and Nanotechnology 15, n. 10 (1 ottobre 2015): 8217–21. http://dx.doi.org/10.1166/jnn.2015.11434.

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Cu–Sn alloy foam is a promising electrode material for Li-ion batteries. In this study, Cu–Sn alloy foam was produced by diffusion-limited electrodeposition in alkaline electrolyte using polyurethane (PU) foam template. Our major concern is to form Cu–Sn alloy foam with nanocrystalline surface morphology by adjusting electrodeposition conditions such as deposition potential and metal ion concentration. Cu–Sn alloy layers comprising of nanoclusters such as nanospheres, nanoellipsoids, and nanoflakes were created depending on electrodeposition conditions. Larger surface area of nanocluster-interconnected Cu–Sn alloy layer was created when both Sn concentration and negative deposition potential were higher. After decomposing PU template thermally, Cu–Sn alloy foam of Cu, Cu6Sn5, and Cu3Sn phases was finally produced.

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Hou, Guang Ya, Ji Yu Li, Lian Kui Wu, Yi Ping Tang, Hua Zhen Cao e Guo Qu Zheng. "Effect of Dealloying Process on Microstructure and Electrochemical Properties of Ni Foam". Materials Science Forum 922 (maggio 2018): 3–7. http://dx.doi.org/10.4028/www.scientific.net/msf.922.3.

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Ni foam with 3D porous structure has attracted attention in the field of catalysis. Expanding the specific surface area of Ni foam is an important method to enhance its chemical properties. In this study, the Cu-Ni/Ni foam were obtained by electroless plating copper on Ni foam and then heat treatment for homogenizing at 750°C. The dealloying of the Cu-Ni/Ni foam was carried out by electrochemical etching for obtaining the Ni foam with hierarchical pore structure. The microstructure, phase and electrochemical performance were characterized by SEM, XRD and electrochemical testing. The results showed that the optimized temperature of electroless plating Cu on Ni foam is 60oC. Ni-Cu alloy can be obtained by counter diffusion above 750°C. With prolonging time of etching, the content of Cu component decreased and the size of pores on the sturts of the Cu-Ni/Ni foam changed from nano to micro scale. The electrochemical properties of the alloywere significantly higher than that of the pure nickel foam.

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Wong, Pei-Chun, Sin-Mao Song, Pei-Hua Tsai, Muhammad Jauharul Maqnun, Wei-Ru Wang, Jia-Lin Wu e Shian-Ching (Jason) Jang. "Using Cu as a Spacer to Fabricate and Control the Porosity of Titanium Zirconium Based Bulk Metallic Glass Foams for Orthopedic Implant Applications". Materials 15, n. 5 (3 marzo 2022): 1887. http://dx.doi.org/10.3390/ma15051887.

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In this study, a porous titanium zirconium (TiZr)-based bulk metallic foam was successfully fabricated using the Cu spacer by employing the hot press method. TiZr-based bulk metallic foams with porosities ranging from 0% to 50% were fabricated and analyzed. The results indicate that thermal conductivity increased with the addition of Cu spacer; the increased thermal conductivity reduced the holding time in the hot press method. Moreover, the compressive strength decreased from 1261 to 76 MPa when the porosity of the TiZr-based bulk metallic foam increased to 50%, and the compressive strength was predictable. In addition, the foam demonstrated favorable biocompatibility in cell viability, cell migration capacity, and calcium deposition tests. Moreover, the pore size of the porous TiZr-based bulk metallic foam was around 120 µm. In conclusion, TiZr-based bulk metallic foam has favorable biocompatibility, mechanical property controllability, and porous structure for bone ingrowth and subsequent enhanced osteointegration. This porous TiZr-based bulk metallic foam has great potential as an orthopedic implant to enhance bone healing and decrease healing time.

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Mohd Zahri, Nur Amirah, Yukio Miyashita, Tadashi Ariga, A. S. M. Abdul Haseeb e Nazatul Liana Sukiman. "Brazing of Copper Foam Using Cu-4.0Sn-9.9Ni-7.8P Filler Foil: Effect of Brazing Temperature and Copper Foam Pore Density". Key Engineering Materials 982 (3 luglio 2024): 67–76. http://dx.doi.org/10.4028/p-tb1zf5.

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Copper (Cu) foam is a promising material that owns a high surface area that can be utilized in a thermal application. In this research, the brazing of Cu substrate to Cu foam in the sandwich configuration using Cu alloy filler foil was carried out. The foam at different pore per inch (PPI) of 15, 25 and 50 are brazed at different brazing temperatures. Mechanical and microstructure analysis were conducted to investigate a suitable brazing temperature and the best pore density of foam. The compressive strength of brazed 50 PPI foam has yielded the highest due to the highly dense interconnected branches. While the highest shear strength of brazed interface using 15 PPI foam has been recorded. The large branch size of 15 PPI foam has contributed to the sound joint between the brazed joint interface of Cu substrate and foam. Both mechanicals analysis above exhibits a highest strength at 660 °C as a brazing temperature The shear stress-strain curve of Cu substrate and foam brazed joint interface shows a brittle behaviour which accordance with the discoverable brittle phases of Cu3P and Ni3P using X-ray diffraction (XRD). Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX) have presented the formation of Cu3P and Ni3P at the brazed joint interface of Cu substrate and foam.

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Farhan, Israa S., Akeel A. Mohammed e Manar S. M. Al-Jethelah. "The Effect of Uneven Metal Foam Distribution on Solar Compound Parabolic Trough Collector Receiver Thermal Performance". Tikrit Journal of Engineering Sciences 31, n. 1 (20 marzo 2024): 291–305. http://dx.doi.org/10.25130/tjes.31.1.24.

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Solar energy is a key player among other renewable energies that reduce greenhouse gases and replace conventional fuel, i.e., to solve global warming and fossil fuel descending issues. However, the thermal solar systems’ performance should be enhanced to cope with intermittent solar radiation. Metal foam can be used as an enhancer in solar collectors’ receivers. However, metal foams are associated with pressure drop. To benefit from the metal foam as a thermal enhancer and overcome the pressure drop issue, the present study numerically and experimentally investigates a novel Compound Parabolic Solar Collector (CPC) receiver with innovative uneven metal foam inserts of varying thickness. Two pores per inch (PPI) Cu-foam inserts, PPI10 and PPI20, were tested. These inserts were strategically placed at three different positions along the receiver, with thicknesses of 3 cm, 2 cm, and 1 cm starting from the inlet side. In the experimental part, three tubular receivers were tested, empty, i.e., without metal foam, inserted with Cu-foam of PPI10, and inserted with Cu-foam of PPI20. The experiments were conducted from 09:00 AM to 04:00 PM. The investigation involved water volume flow rates from 0.2 to 0.6 l/min. The numerical part included solving the governing equations, i.e., mass, momentum, and energy conservation, simulating conditions similar to the experiments. The Brinckman model described the fluid flow through the metal foam. The thermal performance of the CPC system was evaluated using the Nusselt number (Nu), thermal efficiency, water bulk temperature, and water outlet-inlet temperature difference. Inserting Cu-foam of PPI20 resulted in the hourly maximum Nu and thermal efficiency compared to the empty and PPI10 cases. Experimentally, the hourly maximum Nu was 8.9, 8.4, and 7.9 for PPI20, PPI10, and empty receivers, respectively, at 0.6 l/min. The average thermal efficiency was 88.3, 85, and 81.9 for PPI20, PPI10, and empty receivers, respectively, at 0.6 l/min. As for the outlet-inlet water temperature difference, the highest values were at 0.2 l/min. Again, PPI20 recorded the best results, i.e., 23.3 K, 21.5 K, and 20.2 K for PPI20, PPI10, and empty cases, respectively.

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Balela, Mary Donnabelle L., Reginald E. Masirag, Francis O. Pacariem Jr. e Juicel Marie D. Taguinod. "Electrochemical Fabrication of Porous Interconnected Copper Foam". Key Engineering Materials 902 (29 ottobre 2021): 9–14. http://dx.doi.org/10.4028/www.scientific.net/kem.902.9.

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An interconnected copper network or copper foam was successfully fabricated by electrochemical deposition using polyethylene glycol (PEG) and sodium bromide (NaBr) as additives. Both the amount of PEG and the current density were varied to obtain a Cu foam with the smallest pore diameter and wall thickness. The increasing amount of PEG resulted in a decrease in pore diameter. However, the wall thickness of the Cu network was increased. At 800 mg/L PEG and 20 mM NaBr, the average pore size of the foam was about 11.03 µm. Dendritic formation was also observed on the walls of the Cu foam. Further, higher current density resulted in increased dendritic growth. X-ray diffraction confirms that the Cu foam was spontaneously oxidized in air, leading to the formation of cuprous oxide (Cu2O).

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Vainoris, Modestas, Henrikas Cesiulis e Natalia Tsyntsaru. "Metal Foam Electrode as a Cathode for Copper Electrowinning". Coatings 10, n. 9 (25 agosto 2020): 822. http://dx.doi.org/10.3390/coatings10090822.

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The geometry of porous materials is complex, and the determination of the true surface area is important because it affects current density, how certain reactions will progress, their rates, etc. In this work, we have investigated the dependence of the electrochemical deposition of copper coatings on the geometry of the copper substrate (flat plates or 3D foams). Chronoamperometric measurements show that copper deposition occurs 3 times faster on copper foams than on a flat electrode with the same geometric area in the same potential range, making metal foams great electrodes for electrowinning. Using electrochemical impedance spectroscopy (EIS), the mechanism of copper deposition was determined at various concentrations and potentials, and the capacities of the double electric layer (DL) for both types of electrodes were calculated. The DL capacity on the foam electrodes is up to 14 times higher than that on the plates. From EIS data, it was determined that the charge transfer resistance on the Cu foam electrode is 1.5–1.7 times lower than that on the Cu plate electrode. Therefore, metal foam electrodes are great candidates to be used for processes that are controlled by activation polarization or by the adsorption of intermediate compounds (heterogeneous catalysis) and processes occurring on the entire surface of the electrode.

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Chanda, Debabrata, Ramato Ashu Tufa, David Aili e Suddhasatwa Basu. "Electroreduction of CO₂ to ethanol by electrochemically deposited Cu-lignin complexes on Ni foam electrodes". Nanotechnology 33, n. 5 (12 novembre 2021): 055403. http://dx.doi.org/10.1088/1361-6528/ac302b.

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Abstract A low cost, non-toxic and highly selective catalyst based on a Cu-lignin molecular complex is developed for CO2 electroreduction to ethanol. Ni foam (NF), Cu–Ni foam (Cu–NF) and Cu-lignin-Ni foam (Cu-lignin-NF) were prepared by a facile and reproducible electrochemical deposition method. The electrochemical CO2 reduction activity of Cu-lignin-NF was found to be higher than Cu–NF. A maximum faradaic efficiency of 23.2% with current density of 22.5 mA cm−2 was obtained for Cu-lignin-NF at −0.80 V (versus RHE) in 0.1 M Na2SO4 towards ethanol production. The enhancement of catalytic performance is attributed to the growth of the number of active sites and the change of oxidation states of Cu and NF due to the presence of lignin.

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Balela, Mary Donnabelle L., Reginald E. Masirag, Francis O. Pacariem Jr. e Juicel Marie D. Taguinod. "Effect of NABr on the Pore Size and Surface Morphology of Cu Foam Prepared by Hydrogen Bubble Templating". Key Engineering Materials 880 (marzo 2021): 83–88. http://dx.doi.org/10.4028/www.scientific.net/kem.880.83.

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Binderless supercapacitor electrodes are currently being employed to increase the surface contact between the active material and current collector, leading to enhanced capacitance. In binderless electrodes, the active material is directly grown on the surface of the current collector, omitting the use of insulative polymer-based binders. In this work, Cu foam was successfully electrodeposited on Cu sheet by dynamic hydrogen bubble templating (DHBT) using polyethylene glycol (PEG) and sodium bromide (NaBr) as additives. The current density was set at 3 A·cm-2 and electrodeposition was performed for 20 s. At 200 mg/L PEG, increasing the NaBr concentration from 0 to 80 mM produced Cu foam with decreasing pores sizes of about 75.15 to 34.10 μm. However, the walls of the interconnected pores became thicker as the pore diameters were reduced. This indicates that NaBr promotes Cu deposition rather than hydrogen evolution reaction (HER), leading to smaller pore sizes. X-ray diffraction confirms the oxidation of the Cu foam under ambient conditions forming cuprous oxide (Cu2O). The Cu2O/Cu foam was then utilized as binderless electrode for supercapacitor, resulting to a specific capacitance of 0.815 F·cm-2 at 5 mV·s-1. Results show the potential of the fabricated Cu2O/Cu foam as binderless electrode for pseudo-type supercapacitors.

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Costanza, Girolamo, e Maria Elisa Tata. "Parameters Affecting Energy Absorption in Metal Foams". Materials Science Forum 941 (dicembre 2018): 1552–57. http://dx.doi.org/10.4028/www.scientific.net/msf.941.1552.

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Recent research findings on the mechanical behavior of metal foams are summarized in this work. Thanks to their properties in compressive tests, a wide range of foamed materials has been considered for energy-absorption applications such as Al, Fe, Ti, Ni and its alloys. The main parameters affecting energy absorption are focused and presented: cell size, relative density, strain rate, hybrid foam (Al-Cu, Al-Ni), base metal, and composites structures (Al-foam filled tube and sandwich). Metal foam response, impact resistance and failure are discussed in many configurations and test conditions. The results of finite elements modelling and its validation by means of mechanical tests are discussed too.

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Xia, Yuanyuan, Wang Hu, Yiyuan Yao, Shuhui Chen, Seongki Ahn, Tao Hang, Yunwen Wu e Ming Li. "Application of electrodeposited Cu-metal nanoflake structures as 3D current collector in lithium-metal batteries". Nanotechnology 33, n. 24 (25 marzo 2022): 245406. http://dx.doi.org/10.1088/1361-6528/ac5b53.

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Abstract Since uncontrolled lithium (Li) dendrite growth and dendrite-induced dead Li severely limit the development of Li metal batteries, 3D Cu current collectors can effectively alleviate these problems during Li plating/stripping. Herein, one-step galvanostatic electrodeposition method is employed to fabricate a new current collector on Cu foam decorated with large-scale and uniform 3D porous Cu-based nanoflake (NF) structures (abbreviated as 3D Cu NF@Cu foam). This 3D structure with large internal surface areas not only generates lithophilic surface copper oxides and hydroxides as charge centers and nucleation sites for Li insertion/extraction, but also endows abundant space with interlinked NFs for buffering the cell volume expansion and increasing battery performance. As a result, Li-deposited 3D Cu NF@Cu foam current collector can realize stable cycling over 455 cycles with an average Coulombic efficiency of 98.8% at a current density of 1.0 mA cm−2, as well as a prolonged lifespan of >380 cycles in symmetrical cell without short-circuit, which are superior to those of blank Cu foam current collector. This work realizes Li metal anode stabilization by constructing 3D porous Cu NFs current collectors, which can advance the development of Li metal anode for battery industries.

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Kim, Chang-Eun, Raheleh M. Rahimi, Nia Hightower, Ioannis Mastorakos e David F. Bahr. "Synthesis, microstructure, and mechanical properties of polycrystalline Cu nano-foam". MRS Advances 3, n. 8-9 (2018): 469–75. http://dx.doi.org/10.1557/adv.2018.128.

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AbstractA polycrystalline Cu foam with sub-micron ligament sizes was formed by creating a non-woven fabric via electrospinning with a homogeneous mixture of polyvinyl alcohol(PVA)-and copper acetate(Cu(Ac)2). Thermogravimetric measurement of the electrospun fabric of the precursor solution is reported. Oxidizing the precursor fabric at 773K formed an oxide nano-foam; subsequent heating at 573K with a reducing gas transformed the CuO nano-foam to Cu with a similar ligament and meso-scale pore size morphology. A cross-section prepared by focused ion beam lift-out shows the polycrystalline structure with multi-scale porosity. The mechanical property of the Cu nano-foam is measured by nano-indentation. The load-depth curves and deduced mechanical properties suggest that additional intra-ligament pores lead to unique structure-property relations in this non-conventional form of metal.

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Li, Cong Bo, Wei Wei Chen e Lu Wang. "Preparation and Characterization of Amorphous Al-Based Metal Foams". Materials Science Forum 816 (aprile 2015): 682–87. http://dx.doi.org/10.4028/www.scientific.net/msf.816.682.

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Amorphous Al-Cu-Ti metal foams with the porosity of 65% were prepared by spark plasma sintering with both the diameter and height of 10 mm. The SPS process was carried out under the pressure, the dwell time and the temperatures of 300 MPa, 5min and 623-673K, respectively. The microstructure and mechanical behavior of the amorphous Al-Cu-Ti metal foams were investigated. The results showed that sintering at high temperatures improved the crystallinity and adhesion between particles. The intermetallic compounds, i.e. Al-Ti, Al-Cu and Al-Cu-Ti were identified from the XRD patterns. It was found that weak adhesion and irregular shape of NaCl might reduce the mechanical properties. The highest strength of amorphous Al-based metal foam sintered at 653K, 300MPa was 7.97MPa.

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Sukkaneewat, Benjatham, Duangruthai Sridaeng e Nuanphun Chantarasiri. "Fully water-blown polyisocyanurate-polyurethane foams with improved mechanical properties prepared from aqueous solution of gelling/ blowing and trimerization catalysts". e-Polymers 19, n. 1 (29 maggio 2019): 277–89. http://dx.doi.org/10.1515/epoly-2019-0028.

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Abstract (sommario):

AbstractFully water-blown polyisocyanurate-polyurethane (PIR-PUR) foams with improved mechanical properties have been prepared using aqueous solutions of metal-ammonia complex, Cu(Am) or Zn(Am), as gelling/blowing catalysts and potassium octoate (KOct) solution in diethylene glycol as a trimerization catalyst. Two catalyst mixtures, Cu(Am)+KOct and Zn(Am)+KOct, were obtained as homogeneous aqueous solutions. In comparison to commercial catalyst system, DMCHA+KOct (DMCHA = N,N-dimethylcyclohexylamine), Cu(Am) and Zn(Am) could be miscible with KOct solution and water easier than DMCHA. This miscibility improvement led Cu(Am)+KOct and Zn(Am)+KOct to show faster catalytic reactivity in PIR-PUR foam reactions than DMCHA+KOct. All obtained PIR-PUR foams showed self-extinguishing properties and achieved HF1 materials. However, PIR-PUR foams prepared from Cu(Am)+KOct and Zn(Am)+KOct at NCO:OH ratio of 2:1 had suitable density for industrial applications and showed higher compressive strength than that prepared from DMCHA+KOct. These foams have high potential to apply as insulations for constructions, core laminates in wall panel or storage tanks.

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23

Lv, Sa, Wenshi Shang, Huan Wang, Xuefeng Chu, Yaodan Chi, Chao Wang, Jia Yang, Peiyu Geng e Xiaotian Yang. "Design and Construction of Cu(OH)2/Ni3S2 Composite Electrode on Cu Foam by Two-Step Electrodeposition". Micromachines 13, n. 2 (30 gennaio 2022): 237. http://dx.doi.org/10.3390/mi13020237.

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Abstract (sommario):

A Cu(OH)2/Ni3S2 composite has been designed and in situ constructed on Cu foam substrate by facile two-step electrodeposition. Cu(OH)2 is achieved on Cu foam by galvanostatic electrodeposition, and the subsequent coating of Ni3S2 is realized by cyclic voltammetric (CV) electrodeposition. The introduction of Cu(OH)2 provides skeleton support and a large specific surface area for the Ni3S2 electrodeposition. Benefiting from the selection of different components and preparation technology, the Cu(OH)2/Ni3S2 composite exhibits enhanced electrochemical properties with a high specific capacitance of 4.85 F cm−2 at 2 mA cm−2 and long-term cyclic stability at 80.84% (4000 cycles).

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24

Laçaj, Endri, Pascal Jolly, Jean Bouyer e Pascal Doumalin. "Elastic and damping characterization of open-pore metal foams filled or not with an elastomer for vibration control in turbomachinery". Mechanics & Industry 25 (2024): 23. http://dx.doi.org/10.1051/meca/2024021.

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Abstract (sommario):

In this work, an experimental investigation into vibration damping of elastomer filled open-pore metal foams and their effectiveness as a bearing support in turbomachinery is presented. The polyurethane fillers known for their high-energy absorption capacity were chosen to enhance the damping performance of the metal skeleton. Aluminum (Al), copper (Cu) and nickel-chromium foams (NiCr), with different relative density and pore size were tested dynamically using a dedicated device based on a single degree-of-freedom model. The results indicate that the storage modulus and the loss factor for foam-polymer composites were greater than the combined contribution of both phases taken separately. Foam morphology plays an important role in this effect and it is shown that the increase in performance was more significant for higher specific surface area. Fillers with different properties were also considered. The optimal combination of foam and polymer was selected and tested on a rotor kit test bench. Annular shaped samples were placed between the external race of the ball bearing and the housing. The tests were carried out using a flexible rotor configuration where the vibration amplitudes of the rotor were monitored for foam and foam-polyurethane composites for rotational speeds up to 100 Hz while hammer impact tests were performed using a semi-rigid shaft configuration due to higher resonance frequencies. In the first case, no significant difference was observed between the foam, foam composite and the bearings-only set-up. In the second case, the foam composite resulted with the highest energy dissipation capacity.

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25

Lee, Yuan-Gee, Hui-Hsuan Chiao, Yu-Ching Weng e Chyi-How Lay. "The Influence of the Cu Foam on the Electrochemical Reduction of Carbon Dioxide". Inorganics 12, n. 2 (11 febbraio 2024): 57. http://dx.doi.org/10.3390/inorganics12020057.

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Abstract (sommario):

Unlike the flat Cu sheet, we employed Cu foam to explore the specific porous effect on the expanding specific area. We found that the foam structure is superior to the sheet feature in the specific location from the morphology investigation. In the practical measurement of surface area, we found that the adsorbate could aptly agglomerate, resulting in a consequential block in the transport path. The specific location of the Cu foam was underestimated because the channels of the deep foam layer were blocked by the agglomerated adsorbate. To explore the protonation process of the electro-reduction, we adopted the carbonate electrolyte as the control group in contrast to the experimental group, the bicarbonate electrolyte. In the carbonate electrolyte, the primary intermediate was shown to be CO molecules, as verified using XPS spectra. In the bicarbonate electrolyte, the intermediate CO disappeared; instead, it was hydrogenated as a hydrocarbon intermediate, CHO*. The bicarbonate ion was also found to suppress electrocatalysis in the deep structure of the Cu foam because its high-molecular-weight intermediates accumulated in the diffusion paths. Furthermore, we found a promotion of the oxidation valence on the electrode from Cu2O to CuO, when the electrode structure transformed from sheet to foam. Cyclic voltammograms demonstrate a succession of electro-reduction consequences: at low reduction potential, hydrogen liberated by the decomposition of water; at elevated reduction potential, formic acid and CO produced; and at high reduction potential, CH4 and C2H4 were formed from −1.4 V to −1.8 V.

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26

Zhao, Wei, Siyuan He, Chen Zhang, Yuxuan Li, Yi Zhang e Ge Dai. "Generation of a Strength Gradient in Al-Cu-Ca Alloy Foam via Graded Aging Treatment". Metals 12, n. 3 (28 febbraio 2022): 423. http://dx.doi.org/10.3390/met12030423.

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Abstract (sommario):

In this study, a strength gradient is produced in Al-Cu-Ca alloy foam by aging treatment with a temperature gradient. The microscopic results show that the morphology and the amount of Al2Cu strengthening precipitates in the base alloy change with the local aging temperature. Graded microstructures in the base alloy are realized along with the temperature gradient, subsequently producing the strength gradient in the Al-Cu-Ca foam. Under compression, the lower strength portion of the foam sample firstly collapsed until complete densification and then extended to the higher strength portion, suggesting a notable strength gradient. The tailorable graded aging treatment provided a higher degree of freedom in designing and producing the strength gradient in aluminum foam.

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27

Bie, Lili, Xue Luo, Qingqing He, Daiping He, Yan Liu e Ping Jiang. "Hierarchical Cu/Cu(OH)2 nanorod arrays grown on Cu foam as a high-performance 3D self-supported electrode for enzyme-free glucose sensing". RSC Advances 6, n. 98 (2016): 95740–46. http://dx.doi.org/10.1039/c6ra19576h.

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Abstract (sommario):

Hierarchical Cu/Cu(OH)₂ nanorod arrays grown on Cu foam (Cu/Cu(OH)₂ NRA/CF) were prepared via a three-step strategy involving the synthesis of Cu(OH)₂ NRA/CF, the preparation of Cu NRA/CF, and the growth of Cu(OH)₂ nanoparticles on Cu NRA/CF.

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28

Ferraris, Sara, Graziano Ubertalli, Antonio Santostefano e Antonio Barbato. "Aluminum Foams as Permanent Cores in Casting". Materials Proceedings 3, n. 1 (20 febbraio 2021): 3. http://dx.doi.org/10.3390/iec2m-09253.

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Abstract (sommario):

Their low density and high specific stiffness and impact energy/vibration absorption ability make Al-based metal foams promising materials in applications for which a light weight and energy/vibration absorption abilities are crucial. In view of these properties, Al-based foams can be extremely interesting as cores in cast components in order to improve their performances and simplify their whole technological process. However, both in the scientific literature and in technological application, this topic is still poorly explored. In the present work, Al-based metal foams (Cymat foams and Havel metal foams in the form of rectangular bars) are used in a gravity casting experiment of an Al-Si-Cu-Mg alloy (EN AB-46400). The foams were fully characterized before and after insertion in casting. Porosity, cell wall and external skin thickness, microstructure, infiltration degree, and the quality of the interface between the foam core and the dense cast shell, have been investigated by means of optical microscopy and scanning electron microscopy equipped with energy dispersive spectroscopy (SEM-EDS). The analyses evidenced that a continuous and thick external skin protect the foam from infiltration by molten metal, preserving the initial porosity and insert shape. A detailed analysis of the foam’s external skin highlights that the composition of this external skin is crucial for the obtaining of a good joining between the molten metal and the Al foam core. In fact, the presence of Mg oxides on the foam surface prevents bonding, and maintains a gap between the core and the shell. This point opens up the opportunity to design innovative surface modifications for this external skin as promising strategies for the optimization of cast components with a foam core.

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29

Liu, Yangyang, Xue Teng, Yongli Mi e Zuofeng Chen. "A new architecture design of Ni–Co LDH-based pseudocapacitors". Journal of Materials Chemistry A 5, n. 46 (2017): 24407–15. http://dx.doi.org/10.1039/c7ta07795e.

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30

Ma, Xingxing, Yaqing Chang, Zhe Zhang e Jilin Tang. "Forest-like NiCoP@Cu3P supported on copper foam as a bifunctional catalyst for efficient water splitting". Journal of Materials Chemistry A 6, n. 5 (2018): 2100–2106. http://dx.doi.org/10.1039/c7ta09619d.

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31

Matějová, Lenka, Ivana Troppová, Satu Pitkäaho, Kateřina Pacultová, Dagmar Fridrichová, Ondřej Kania e Riitta Laura Keiski. "Oxidation of Methanol and Dichloromethane on TiO2-CeO2-CuO, TiO2-CeO2 and TiO2-CuO@VUKOPOR®A Ceramic Foams". Nanomaterials 13, n. 7 (23 marzo 2023): 1148. http://dx.doi.org/10.3390/nano13071148.

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Abstract (sommario):

The application-attractive form of TiO2, CeO2 and CuO-based open-cell foam supported catalysts was designed to investigate their catalytic performance in oxidation of two model volatile organic compounds—methanol and dichloromethane. TiO2-CeO2, TiO2-CuO and TiO2-CeO2-CuO catalysts as thin films were deposited on VUKOPOR®A ceramic foam using a reverse micelles-controlled sol-gel method, dip-coating and calcination. Three prepared catalytic foams were investigated via light-off tests in methanol and dichloromethane oxidation in the temperature range of 45–400 °C and 100–500 °C, respectively, at GHSV of 11, 600 h−1, which fits to semi-pilot/industrial conditions. TiO2-CuO@VUKOPOR®A foam showed the best catalytic activity and CO2 yield in methanol oxidation due to its low weak Lewis acidity, high weak basicity and easily reducible CuO species and proved good catalytic stability within 20 h test. TiO2-CeO2-CuO@VUKOPOR®A foam was the best in dichloromethane oxidation. Despite of its lower catalytic activity compared to TiO2-CeO2@VUKOPOR®A foam, its highly-reducible -O-Cu-Ce-O- active surface sites led to the highest CO2 yield and the highest weak Lewis acidity contributed to the highest HCl yield. This foam also showed the lowest amount of chlorine deposits.

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32

Koblischka, Michael, Sugali Naik, Anjela Koblischka-Veneva, Masato Murakami, Denis Gokhfeld, Eddula Reddy e Georg Schmitz. "Superconducting YBCO Foams as Trapped Field Magnets". Materials 12, n. 6 (13 marzo 2019): 853. http://dx.doi.org/10.3390/ma12060853.

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Abstract (sommario):

Superconducting foams of YBa 2 Cu 3 O y (YBCO) are proposed as trapped field magnets or supermagnets. The foams with an open-porous structure are light-weight, mechanically strong and can be prepared in large sample sizes. The trapped field distributions were measured using a scanning Hall probe on various sides of an YBCO foam sample after field-cooling in a magnetic field of 0.5 T produced by a square Nd-Fe-B permanent magnet. The maximum trapped field (TF) measured is about 400 G (77 K) at the bottom of the sample. Several details of the TF distribution, the current flow and possible applicatons of such superconducting foam samples in space applications, e.g., as active elements in flux-pinning docking interfaces (FPDI) or as portable strong magnets to collect debris in space, are outlined.

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33

Meng, Fan-Lu, Hai-Xia Zhong, Qi Zhang, Kai-Hua Liu, Jun-Min Yan e Qing Jiang. "Integrated Cu3N porous nanowire array electrode for high-performance supercapacitors". Journal of Materials Chemistry A 5, n. 36 (2017): 18972–76. http://dx.doi.org/10.1039/c7ta05439d.

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34

Hasan, MD Anwarul. "An Improved Model for FE Modeling and Simulation of Closed Cell Al-Alloy Foams". Advances in Materials Science and Engineering 2010 (2010): 1–12. http://dx.doi.org/10.1155/2010/567390.

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Abstract (sommario):

Cell wall material properties of Al-alloy foams have been derived by a combination of nanoindentation experiment and numerical simulation. Using the derived material properties in FE (finite element) modeling of foams, the existing constitutive models of closed-cell Al-alloy foams have been evaluated against experimental results. An improved representative model has been proposed for FE analysis of closed-cell Al-alloy foams. The improved model consists of a combination of spherical and cruciform-shaped cells similar to those of Meguid et al.'s cruciform-hemisphere model (Finite Elem. Anal. Design: 2002, 38, 631). However, the spherical cells, which are smaller in size, are made of thicker cell walls in the new improved model compared to the cruciform-shaped cells, based on observation of the underlying Al-alloy foams. The compressive mechanical properties of Al-3wt.%Si-2wt.%Cu-2wt.%Mg alloy foams of relative density 12%–20% have been obtained by simulation using the improved representative model. While the traditional foam models overpredict the foam strength, the new weaker-cruciform-stronger-hemisphere model is found to predict the foam properties with much better accuracy. It is found that the proposed new model is capable of producing all three different types of deformation pattern of closed-cell metal foams, namely, uniform deformation, layerwise deformation, and the progressive deformation from the locations of lowest densities and highest impurities to those of higher densities and lower impurities.

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35

Markova, Ivania, Valentina Milanova, Tihomir Petrov, Ivan Denev e Olivier Chauvet. "New Porous Nanocomposite Materials for Electrochemical Power Sources". Key Engineering Materials 644 (maggio 2015): 129–32. http://dx.doi.org/10.4028/www.scientific.net/kem.644.129.

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Abstract (sommario):

Intermetallic (Cu-Sn) nanoparticles are synthesized through a borohydride reduction with NaBH4 in a mixture of aqueous solutions of CuCl2.2H2O and SnCl2.2H2O at mass ratio Cu:Sn = 3:2 applying a template technique with a support such as carbon foam. The ratio is chosen in accordance with the Cu-Sn binary system phase diagram. The reductive precipitation is carried out at room temperature and atmospheric pressure. Porous nanocomposites are obtained and studied by scanning and transmission electron microscopy (SEM/TEM), and X-ray diffraction (XRD) analysis. The electrochemical behavior of the synthesized Cu-Sn alloy and the C-based composites (С-foam/Cu-Sn alloy) as positive electrodes is also investigated in a Li-ion battery) using a computer controlled laboratory cycling equipment BA500 Series Battery Analyzer.

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36

Xu, Panpan, Jijun Liu, Tong Liu, Ke Ye, Kui Cheng, Jinling Yin, Dianxue Cao, Guiling Wang e Qiang Li. "Preparation of binder-free CuO/Cu2O/Cu composites: a novel electrode material for supercapacitor applications". RSC Advances 6, n. 34 (2016): 28270–78. http://dx.doi.org/10.1039/c6ra00004e.

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Abstract (sommario):

The results of XRD and XPS demonstrate that CuO/Cu₂O/Cu is prepared successfully via a facile, eco-friendly, one-step template-free growth process. SEM figures show that cubic CuO/Cu₂O/Cu uniformly and densely covers a skeleton of nickel foam.

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37

Ren, Xiang, Xuqiang Ji, Yicheng Wei, Dan Wu, Yong Zhang, Min Ma, Zhiang Liu, Abdullah M. Asiri, Qin Wei e Xuping Sun. "In situ electrochemical development of copper oxide nanocatalysts within a TCNQ nanowire array: a highly conductive electrocatalyst for the oxygen evolution reaction". Chemical Communications 54, n. 12 (2018): 1425–28. http://dx.doi.org/10.1039/c7cc08748a.

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38

Song, Yonggui, Baixi Shan, Bingwei Feng, Pengfei Xu, Qiang Zeng e Dan Su. "A novel biosensor based on ball-flower-like Cu-hemin MOF grown on elastic carbon foam for trichlorfon detection". RSC Advances 8, n. 47 (2018): 27008–15. http://dx.doi.org/10.1039/c8ra04596h.

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Abstract (sommario):

The Cu-hemin MOFs/nitrogen-doped elastic carbon foam (Cu-hemin MOFs/NECF) composite structure was constructed as the supporting matrix to load acetylcholinesterase (AChE) for preparing pesticide biosensors.

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39

Zbib, Mohamad B., Matthew Howard, Michael R. Maughan, Nicolas J. Briot, T. John Balk e David F. Bahr. "The Mechanical Response of Arrays of Carbon Nanotubes Coated with Metallic Shells". MRS Advances 3, n. 45-46 (2018): 2801–8. http://dx.doi.org/10.1557/adv.2018.562.

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Abstract (sommario):

Abstract:A synthesis method to form foams consisting of a shell of metals conformally coated on carbon nanotube (CNT) arrays by electroplating from a single bath electrolyte is demonstrated in this work. A triple cyclic pulse electrodeposition technique was used to deposit Ni and Cu layers on the CNT arrays, and electron microscopy was then used to identify conditions amenable to semi-conformal and island growth morphologies. Nanoindentation of the resulting metallic-CNT composite foam structure, using a flat punch/compression geometry, demonstrates that adding metallic shells to the CNT turf to create a metallic low density foam increases both the hardness and elastic modulus; however, once island growth initiates there is no significant subsequent increase in mechanical properties with increases in deposited metals.

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40

He, Xuefeng, Xin Chen, Rong Chen, Xun Zhu, Qiang Liao, Dingding Ye, Youxu Yu, Wei Zhang e Jinwang Li. "A 3D oriented CuS/Cu2O/Cu nanowire photocathode". Journal of Materials Chemistry A 9, n. 11 (2021): 6971–80. http://dx.doi.org/10.1039/d0ta11020e.

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41

Yuan, Jiongliang, Xuan Wang, Chunhui Gu, Jianjun Sun, Wenming Ding, Jianjun Wei, Xiaoyu Zuo e Cunjiang Hao. "Photoelectrocatalytic reduction of carbon dioxide to methanol at cuprous oxide foam cathode". RSC Advances 7, n. 40 (2017): 24933–39. http://dx.doi.org/10.1039/c7ra03347h.

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42

Lv, Sa, Huan Wang, Fan Yang, Jia Yang, Chao Wang, Yaodan Chi e Xiaotian Yang. "Direct Growth of Ag/Ni(OH)2 Composite on Cu Foam by a Modified Galvanic Displacement Reaction Followed by Electrodeposition". Nano 16, n. 05 (28 aprile 2021): 2150058. http://dx.doi.org/10.1142/s1793292021500582.

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Abstract (sommario):

The Ag/Ni(OH)2 composite has grown directly on Cu foam substrate via a modified galvanic displacement reaction between the mixed solution (AgNO3 and KBr) and Cu foam, followed by subsequent electrodeposition. Cu foam functions as a reducing agent and electrode substrate. The in situ growth strategy enables the active material to form a strong connection with the substrate, which is beneficial for the fast ionic/electronic transport and lowers the equivalent series resistance. On the other hand, the introduction of Ag improves the electrical conductivity of the material and increases the specific surface area, and even participates in the electrochemical reaction as an effective constituent. Such factors can significantly boost the electrochemical performances of the product, including a high specific capacitance of 1755[Formula: see text]F[Formula: see text]g[Formula: see text] at 2.5[Formula: see text]A[Formula: see text]g[Formula: see text] coupled with long-term cyclic stability at 83.87% (5000 cycles).

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43

Wang, Qinghua, Chao Liu, Huixin Wang, Kai Yin, Zhongjie Yu, Taiyuan Wang, Mengqi Ye, Xianjun Pei e Xiaochao Liu. "Laser-Heat Surface Treatment of Superwetting Copper Foam for Efficient Oil–Water Separation". Nanomaterials 13, n. 4 (15 febbraio 2023): 736. http://dx.doi.org/10.3390/nano13040736.

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Abstract (sommario):

Oil pollution in the ocean has been a great threaten to human health and the ecological environment, which has raised global concern. Therefore, it is of vital importance to develop simple and efficient techniques for oil–water separation. In this work, a facile and low-cost laser-heat surface treatment method was employed to fabricate superwetting copper (Cu) foam. Nanosecond laser surface texturing was first utilized to generate micro/nanostructures on the skeleton of Cu foam, which would exhibit superhydrophilicity/superoleophilicity. Subsequently, a post-process heat treatment would reduce the surface energy, thus altering the surface chemistry and the surface wettability would be converted to superhydrophobicity/superoleophilicity. With the opposite extreme wetting scenarios in terms of water and oil, the laser-heat treated Cu foam can be applied for oil–water separation and showed high separation efficiency and repeatability. This method can provide a simple and convenient avenue for oil–water separation.

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44

Yadavalli, SIVA RAM PRASAD, Aravind Kumar Chandiran e Raghuram Chetty. "Electrochemically Deposited Tin on High Surface Area Copper Foam for Enhanced Electrochemical Reduction of CO₂ to Formic Acid". ECS Meeting Abstracts MA2022-01, n. 55 (7 luglio 2022): 2306. http://dx.doi.org/10.1149/ma2022-01552306mtgabs.

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Abstract (sommario):

Conversion of CO2 into valuable chemicals and fuels has received widespread attention as a way to tackle the increased CO2 emissions (Gattrell, Gupta and Co, 2006) and this also resulted in a reduction of dependence on fossil fuels . There are different techniques for CO2 conversion to value-added products, where electrochemical reduction (ECR) of carbon dioxide into chemical fuels is identified as a promising way since energy efficiency is high and the products, especially the chemical fuels can be readily stored. Among the variety of metallic electrodes, especially transition metals investigated for activity towards ECR of CO2, tin (Sn), bismuth (Bi), Indium (In) were found to be selective towards formic acid production. However, it was found that these metals show a low catalytic activity. To enhance the performance of CO2 reduction, three dimensional (3D) porous foam structured catalysts can be employed by increasing the active surface area. These 3D porous foam structures of metallic catalyst can be achieved by electrodeposition process by tuning the deposition parameters such that the evolving hydrogen during deposition can act as a dynamic template to fabricate 3D metal deposit structures with high surface areas (Shin, Dong and Liu, 2003). In this work, a 3D foam of copper is electrochemically deposited onto Cu foil (f-Cu) and Cu mesh (f-Cu mesh). Further, the deposition parameters for the electrodeposition of Sn on 3D Cu foam (Sn/f-Cu) were optimized to investigate the activity towards the ECR of CO2. SEM and EDX technique were employed for the physical characterization of the electrodes, while the produced formic acid from the reactions was quantified using ion chromatography. The results indicated that Sn/f-Cu mesh electrode showed better performance for ECR of CO2 to formic acid compared to Sn deposited copper foil (Sn/Cu) and bare copper foam. It was observed that Sn/f-Cu mesh achieved 83 % maximum faradaic efficiency at -1.6 V vs Ag/AgCl. However, a highest rate of formic acid production of 350 µmol/hr.cm2 was achieved at -1.8 V vs Ag/AgCl which is nearly seven times higher than Sn/Cu at the same potential. A similar analysis is going to be performed with the other formic acid selective catalysts like Bi/f-Cu mesh and In/f-Cu mesh. Based on the above analysis on faradaic efficiency against various electrodes, an optimized electrode will be identified and used in scaled-up electrolyser for CO2 reduction. References Gattrell, M., Gupta, N. and Co, A. (2006) ‘A review of the aqueous electrochemical reduction of CO2 to hydrocarbons at copper’, Journal of Electroanalytical Chemistry, pp. 1–19. doi: 10.1016/j.jelechem.2006.05.013. Shin, H. C., Dong, J. and Liu, M. (2003) ‘Nanoporous Structures Prepared by an Electrochemical Deposition Process’, Advanced Materials, 15(19), pp. 1610–1614. doi: 10.1002/adma.200305160.

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45

Wang, Jiankang, Kui Chen, Rong Peng, Yajing Wang, Taiping Xie, Quanxi Zhu, Yuan Peng, Qunying Yang e Songli Liu. "Synergistically enhanced alkaline hydrogen evolution reaction by coupling CoFe layered double hydroxide with NiMoO₄ prepared by two-step electrodeposition". New Journal of Chemistry 45, n. 44 (2021): 20825–31. http://dx.doi.org/10.1039/d1nj02984c.

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Abstract (sommario):

The optimized CoFe LDH/NiMoO4/Cu NW/Cu foam as HER electrocatalyst presents promising application prospect in water splitting with ultralow overpotential of 45 mV at -10 mA/cm2 and long-term durability.

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46

Raju, Risha, Gomathi N., K. Prabhakaran, Kuruvilla Joseph e A. Salih. "Selective catalytic reduction of NO over hierarchical Cu ZSM-5 coated on an alumina foam support". Reaction Chemistry & Engineering 7, n. 4 (2022): 929–42. http://dx.doi.org/10.1039/d1re00505g.

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47

Jiang, Enjun, Jianhong Jiang, Guo Huang, Zhiyi Pan, Xiyong Chen, Guifang Wang, Shaojian Ma, Jinliang Zhu e Pei Kang Shen. "Porous nanosheets of Cu3P@N,P co-doped carbon hosted on copper foam as an efficient and ultrastable pH-universal hydrogen evolution electrocatalyst". Sustainable Energy & Fuels 5, n. 9 (2021): 2451–57. http://dx.doi.org/10.1039/d1se00161b.

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48

Wang, Zao, Huitong Du, Zhiang Liu, Hui Wang, Abdullah M. Asiri e Xuping Sun. "Interface engineering of a CeO2–Cu3P nanoarray for efficient alkaline hydrogen evolution". Nanoscale 10, n. 5 (2018): 2213–17. http://dx.doi.org/10.1039/c7nr08472b.

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49

Li, Qianwen, Mei Li, Shengbo Zhang, Xiao Liu, Xinli Zhu, Qingfeng Ge e Hua Wang. "Tuning Sn-Cu Catalysis for Electrochemical Reduction of CO2 on Partially Reduced Oxides SnOx-CuOx-Modified Cu Electrodes". Catalysts 9, n. 5 (22 maggio 2019): 476. http://dx.doi.org/10.3390/catal9050476.

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Abstract (sommario):

Copper-based bimetallic catalysts have been recently showing promising performance for the selective electrochemical reduction of CO2. In this work, we successfully fabricated the partially reduced oxides SnOx, CuOxmodified Cu foam electrode (A-Cu/SnO2) through an electrodeposition-annealing-electroreduction approach. Notably, in comparison with the control electrode (Cu/SnO2) without undergoing annealing step, A-Cu/SnO2 exhibits a significant enhancement in terms of CO2 reduction activity and CO selectivity. By investigating the effect of the amount of the electrodeposited SnO2, it is found that A-Cu/SnO2 electrodes present the characteristic Sn-Cu synergistic catalysis with a feature of dominant CO formation (CO faradaic efficiency, 70~75%), the least HCOOH formation (HCOOH faradaic efficiency, <5%) and the remarkable inhibition of hydrogen evolution reaction. In contrast, Cu/SnO2 electrodes exhibit a SnO2 coverage-dependent catalysis—a shift from CO selectivity to HCOOH selectivity with the increasing deposited SnO2 on Cu foam. The different catalytic performance between Cu/SnO2 and A-Cu/SnO2 might be attributed to the different content of Cu atoms in SnO2 layer, which may affect the density of Cu-Sn interface on the surface. Our work provides a facile annealing-electroreduction strategy to modify the surface composition for understanding the metal effect towards CO2 reduction activity and selectivity for bimetallic Cu-based electrocatalysts.

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50

Chang, Bing, Xia-Guang Zhang, Zhaojun Min, Weiwei Lu, Zhiyong Li, Jikuan Qiu, Huiyong Wang, Jing Fan e Jianji Wang. "Efficient electrocatalytic conversion of CO2 to syngas for the Fischer–Tropsch process using a partially reduced Cu3P nanowire". Journal of Materials Chemistry A 9, n. 33 (2021): 17876–84. http://dx.doi.org/10.1039/d1ta03854k.

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Abstract (sommario):

A partially reduced cuprous phosphide nanowire with surface phosphorus vacancies supported by copper foam (R-Cu3P/Cu) was synthesized by a doping-induced strategy, and the R-Cu3P/Cu shows outstanding activity for CO2-to-syngas conversion.

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