Search Results (31)

As the crucial current collector for lithium-ion batteries (LIBs), electrolytic copper foils are generally manufactured by electrodeposition in acidic copper sulfate solution. However, there are many disadvantages for traditional electrolytic copper foils, such as coarse grains, insufficient mechanical properties, and high energy consumption. In order to improve the performances of electrolytic copper foil, a novel cuprous electrodeposition system was developed in this study. A soluble cuprous coordination compound was synthesized. In addition, XPS, FT-IR spectrum, as well as single-crystal X-ray diffraction illustrated that thiourea coordinated with Cu(I) through S atom and therefore stabilized Cu(I) by the formation of CuCl·3TU. Importantly, the corresponding electrochemical behaviors were investigated. In aqueous solution, two distinct reduction processes were demonstrated by linear sweep voltammetry (LSV) at rather negative potentials, including the reduction of adsorbed state and non-adsorbed state. Moreover, the observed inductive loops in electrochemical impedance spectroscopy further confirmed the adsorption phenomenon. More significantly, the designed cuprous electrodeposition system could contribute to low energy consumptions during electrolysis. and produce ultrathin nanocrystalline copper foils with appropriate roughness. Consequently, the electrolysis method based on CuCl·3TU could provide an improved approach for copper foils manufacturing in advanced LIBs fabrication. Full article

Dechlorination is a crucial strategy for archeological bronze stabilization to resist corrosion induced by cuprous chloride (CuCl). Conventional samples, either archeological or simulated ones, have deficiencies in revealing dechlorination mechanisms for their complex rust layers and difficulties in quantifying chlorine content. In this work, samples with fixed chlorine amounts were prepared by compressing method to solve overcomplicated and unquantifiable problems. Then, patina profiles and desalinization solutions were analyzed to revisit the dechlorination mechanism across varying solution concentrations and current densities after dechlorination treatments. Results indicate that the sodium hydroxide (NaOH) desalinization method is achieved by converting CuCl to trihydroxychloride (Cu₂(OH)₃Cl). However, this transformation leads to an expansion of the CuCl layer, nearly doubling the CuCl layer thickness at the current density of 25 μA/cm². Dechlorination solution measurements provide information on quantifying chlorine removal and dechlorination progress. Theoretically, the endpoint (c₀) for the NaOH dechlorination method is supposed to be a chloride ion concentration of 358.2 ppm. As the NaOH solution concentrations vary from 10⁻⁶ to 10⁻², CuCl dechlorination progress (E_t=24h) calculations are at about 3% to 6% at 24 h. Applying the current significantly improves the effectiveness of dechlorination at 2.5 μA/cm². However, the chloride ion concentration in the solution starts to decrease after reaching a current density of 12.5 μA/cm², even dropping to 12.07 ppm at 25 μA/cm². According to a theoretical analysis, chlorine evolution during electrolytic processes would be responsible for this phenomenon. Full article

The pseudocapacitive effect can improve the electrochemical lithium storage capacity at high-rate current density. However, the cycle stability is still unsatisfactory. To overcome this issue, a multivalent oxide with a carbon coating represents a plausible technique. In this work, a CuO–Cu₂O@C composite has been constructed by a one-step bilayer salt-baking process and utilized as anode material for lithium-ion batteries. At a current density of 2.0 A g⁻¹, the as-prepared composite delivered a stable discharge capacity of 431.8 mA h g⁻¹ even after 600 cycles. The synergistic effects of the multivalence, the pseudocapacitive contribution from copper, and the carbon coating contribute to the enhanced electrochemical lithium storage performance. Specifically, the existence of cuprous suboxide improves the electrochemical conductivity, the pseudocapacitive effect enhances the lithium storage capacity, and the presence of carbon ensures cycle stability. The testing results show that CuO–Cu₂O@C composite has broad application prospects in portable energy storage devices. The present work provides an instructive precedent for the preparation of transition metal oxides with controllable electronic states and excellent electrochemical performance. Full article

In order to systematize and expand knowledge about copper-containing composite materials as hybrid ion exchangers, in this study, fine metallic copper particles were dispersed within the matrix of a carboxyl cation exchanger (CCE) with a macroporous and gel-type structure thanks to the reduction of Cu₂O particles precipitated within the matrix earlier. It was possible to introduce as much as 22.0 wt% Cu⁰ into a gel-type polymeric carrier (G/H#Cu) when an ascorbic acid solution was used to act as a reducer of Cu₂O and a reagent transforming the functional groups from Na⁺ into the H⁺ form. The extremely high shrinkage of the porous skeleton containing –COOH groups (in a wet and also dry state) and its limited affinity for water protected the copper from oxidation without the use of special conditions. When macroporous CCE was used as a host material, the composite material (M/H#Cu) contained 18.5 wt% Cu, and copper particles were identified inside the resin beads, but not on their surface where Cu²⁺ ions appeared during drying. Thermal analysis in an air atmosphere and under N₂ showed that dispersing metallic copper within the resin matrix accelerated its decomposition in both media, whereby M/H#Cu decomposed faster than G/H#Cu. It was found that G/H#Cu contained 6.0% bounded water, less than M/H#Cu (7.5%), and that the solid residue after combustion of G/H#Cu and M/H#Cu was CuO (26.28% and 22.80%), while after pyrolysis the solid residue (39.35% and 26.23%) was a mixture of carbon (50%) and metallic copper (50%). The presented composite materials thanks to the antimicrobial, catalytic, reducing, deoxygenating and hydrophobic properties of metallic copper can be used for point-of-use and column water/wastewater treatment systems. Full article

Microplastics (MP) encompass not only plastic products but also paint particles. Marine microdebris, including MP, was retrieved from five sampling stations spanning Nagasaki-Goto island and was classified into six types, primarily consisting of MP (A), Si-based (B), and Cu-based (C) paint particles. Type-A particles, i.e., MP, were exceedingly small, with 74% of them having a long diameter of 25 µm or less. The vertical distribution of type C, containing cuprous oxide, exhibited no depth dependence, with its dominant size being less than 7 μm. It was considered that the presence of type C was associated with a natural phenomenon of MP loss. To clarify this, polypropylene (PP) samples containing cuprous oxide were prepared, and their accelerated degradation behavior was studied using a novel enhanced degradation method employing a sulfate ion radical as an initiator. Infrared spectroscopy revealed the formation of a copper soap compound in seawater. Scanning electron microscopy/energy-dispersive X-ray spectroscopy analysis indicated that the chemical reactions between Cl⁻ and cuprous oxide produced Cu⁺ ions. The acceleration of degradation induced by the copper soap formed was studied through the changes in the number of PP chain scissions, revealing that the presence of type-C accelerated MP degradation. Full article

Biofouling is a major concern in marine industries. The use of traditional toxic antifouling coatings is forbidden or severely restricted. This study aimed to provide a green and effective antifouling coating. The coating was prepared using a polydimethylsiloxane (PDMS) matrix and Cu-doped zinc sulfide (ZnS:Cu). Four samples with different ZnS:Cu contents (1, 10, 20, and 50 wt%) were prepared. Pristine PDMS (0 wt%) was used as the control. The results showed that all coatings had hydrophobic surfaces conducive to combating biofouling. In tests against B. Subtilis, the 1, 10, 20, and 50 wt% samples showed enhanced antifouling capabilities compared to the 0 wt% sample. In static and dynamic tests against Chlorella, the antifouling capability increased with increasing ZnS:Cu content and the 50 wt% sample showed the best antifouling capability. The possible antifouling mechanisms of these coatings include the release of ions (Zn²⁺ and Cu⁺), induction of deformation, and fluorescence emission. This study provides a reference for the application of Zn²⁺/Cu⁺ combinations to combat marine biofouling. Full article

To enhance the leaching of chalcopyrite concentrates, this study evaluated a new process for extracting copper using iodized solutions and sulfuric acid diluted in seawater without pressure or high temperatures. The work involved a leaching test carried out under various conditions by varying the concentrations of chloride ions, H₂SO₄, and an evenly distributed oxygen supply in an aeration system. It was demonstrated that Cl⁻ ion addition could promote the chalcopyrite-leaching process. The leaching efficiency of copper reached 70% after 96 h. However, a chloride ion dosage excess can have the opposite effect on extraction, reducing copper recovery. XRD and SEM-EDS results showed that cuprous chloride (CuCl) was formed at high dosages (>0.5 M); meanwhile, at a lower dosage, elemental sulfur (S) was formed in the presence of sulfuric acid solution and seawater medium. In contrast, in an aerated system, surface roughness markedly increased due to continuous oxidation on the surface of the ore. This change in morphology and the high value of the redox potential, given by the aerated system and the acidic environment, allowed copper recovery of up to 70% after 96 h. The results showed that an aerated system is the most effective factor in chalcopyrite concentrate leaching. Full article

Mercuric ion (Hg²⁺) in aqueous media is extremely toxic to the environment and organisms. Therefore, the ultra-trace electrochemical determination of Hg²⁺ in the environment is of critical importance. In this work, a new electrochemical Hg²⁺ sensing platform based on porous activated carbon (BC/Cu₂O) modified with cuprous oxide was developed using a simple impregnation pyrolysis method. Differential pulse anodic stripping voltammetry (DPASV) was used to investigate the sensing capability of the BC/Cu₂O electrode towards Hg²⁺. Due to the excellent conductivity and large specific surface area of BC, and the excellent catalytic activity of Cu₂O nanoparticles, the prepared BC/Cu₂O electrode exhibited excellent electrochemical activity. The high sensitivity of the proposed system resulted in a low detection limit of 0.3 ng·L⁻¹ and a wide linear response in the ranges from 1.0 ng·L⁻¹ to 1.0 mg·L⁻¹. In addition, this sensor was found to have good accuracy, acceptable precision, and reproducibility. All of these results show that the BC/Cu₂O composite is a promising material for Hg²⁺ electrochemical detection. Full article

Constructed on the benzothiazole-oxanthracene structure, a fluorescent probe RBg for Cu⁺ was designed under the ESIPT mechanism and synthesized by incorporating amide bonds as the connecting group and glyoxal as the identifying group. Optical properties revealed a good sensitivity and a good linear relationship of the probe RBg with Cu⁺ in the concentration range of [Cu⁺] = 0–5.0 μmol L⁻¹. Ion competition and fluorescence-pH/time stability experiments offered further possibilities for dynamic Cu⁺ detection in an aqueous environment. HRMS analysis revealed a possible 1:1 combination of RBg and Cu⁺. In addition, colorimetric Cu⁺ detection and lysosome-targeted properties of the probe RBg were analyzed through RBg-doped PVDF nanofiber/test strips and RBg-Mito/Lyso trackers that were co-stained in living HeLa cells, enabling the probe’s future applications as real-time detection methods for dynamic Cu⁺ tracking in the lysosomes and Cu⁺ detection under diversified conditions. Full article

Iodine is a nuclide of crucial concern in radioactive waste management. Nanomaterials selectively adsorb iodine from water; however, the efficient application of nanomaterials in engineering still needs to be developed for radioactive wastewater deiodination. Artemia egg shells possess large surface groups and connecting pores, providing a new biomaterial to remove contaminants. Based on the Artemia egg shell-derived biochar (AES biochar) and in situ precipitation and reduction of cuprous, we synthesized a novel nanocomposite, namely porous biochar-confined nano-Cu₂O/Cu⁰ (C-Cu). The characterization of C-Cu confirmed that the nano-Cu₂O/Cu⁰ was dispersed in the pores of AES biochar, serving in the efficient and selective adsorption of iodide and iodate ions from water. The iodide ion removal by C-Cu when equilibrated for 40 min exhibited high removal efficiency over the wide pH range of 4 to 10. Remarkable selectivity towards both iodide and iodate ions of C-Cu was permitted against competing anions (Cl⁻/NO₃⁻/SO₄²⁻) at high concentrations. The applicability of C-Cu was demonstrated by a packed column test with treated effluents of 1279 BV. The rapid and selective removal of iodide and iodate ions from water is attributed to nanoparticles confined on the AES biochar and pore-facilitated mass transfer. Combining the advantages of the porous biochar and nano-Cu₂O/Cu⁰, the use of C-Cu offers a promising method of iodine removal from water in engineering applications. Full article

Plant-derived polyphenolic chemicals are important components of human nutrition and have been found to have chemotherapeutic effects against a variety of cancers. Several studies in animal models have proven polyphenols’ potential to promote apoptosis and tumor regression. However, the method by which polyphenols show their anticancer effects on malignant cells is not well understood. It is generally known that cellular copper rises within malignant cells and in the serum of cancer patients. In this communication, investigations reveal that naringin (a polyphenol found in citrus fruits) can strongly suppress cell proliferation and trigger apoptosis in various cancer cell lines in the presence of copper ions. The cuprous chelator neocuproine, which confirms copper-mediated DNA damage, prevents such cell death to a large extent. The studies further show that the cellular copper transporters CTR1 and ATP7A have a role in the survival dynamics of malignant cells after naringin exposure. The findings emphasize the crucial function of copper dynamics and mobilization in cancer cells and pave the path for a better understanding of polyphenols as nutraceutical supplements for cancer prevention and treatment. Full article

Pathogenic bacteria can remain viable on fabrics for several days and therefore are a source of infection. Antimicrobial fabrics are a potential method of reducing such infections, and advances in antimicrobial fabrics can be enhanced by knowledge of how the fabric kills bacteria. Metal oxides have been considered and used as antimicrobial ingredients in self-sanitizing surfaces, including in clinical settings. In this work, we examine how the addition of cuprous oxide (Cu₂O) particles to polypropylene fibers kills bacteria. First, we show that the addition of the Cu₂O particles reduces the viability of common hospital pathogens, Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus pneumoniae, by 99.9% after 30 min of contact with the treated polypropylene. Then, we demonstrate that the main killing effect is due to the drying of the bacteria onto the cuprous oxide particles. There is also a weaker effect due to free Cu⁺ ions that dissolve into the liquid. Other dissolved species were unimportant. Chelation of these Cu⁺ ions in soluble form or precipitation removes their antimicrobial activity. Full article

Data on alkaloid interactions with the physiologically important transition metals, iron and copper, are mostly lacking in the literature. However, these interactions can have important consequences in the treatment of both Alzheimer’s disease and cancer. As isoquinoline alkaloids include galanthamine, an approved drug for Alzheimer’s disease, as well as some potentially useful compounds with cytostatic potential, 28 members from this category of alkaloids were selected for a complex screening of interactions with iron and copper at four pathophysiologically relevant pH and in non-buffered conditions (dimethyl sulfoxide) by spectrophotometric methods in vitro. With the exception of the salts, all the alkaloids were able to chelate ferrous and ferric ions in non-buffered conditions, but only five of them (galanthine, glaucine, corydine, corydaline and tetrahydropalmatine) evoked some significant chelation at pH 7.5 and only the first two were also active at pH 6.8. By contrast, none of the tested alkaloids chelated cuprous or cupric ions. All the alkaloids, with the exception of the protopines, significantly reduced the ferric and cupric ions, with stronger effects on the latter. These effects were mostly dependent on the number of free aromatic hydroxyls, but not other hydroxyl groups. The most potent reductant was boldine. As most of the alkaloids chelated and reduced the ferric ions, additional experimental studies are needed to elucidate the biological relevance of these results, as chelation is expected to block reactive oxygen species formation, while reduction could have the opposite effect. Full article

Copper content in copper smelter slag exceeds that in copper ores, which has attracted increasing interest to recover copper from this by-product of pyrometallurgical copper production. The isopropanol-sulfuric acid-ozone system has been tested under different conditions to extract this metal from copper smelter slag containing chalcopyrite as a copper mineral. Isopropanol as a solvent played a key role in increasing the copper recovery to 87% after 5 h of leaching, while the use of an aqueous solution of sulfuric acid allowed only 13% of copper to be recovered. Iron extraction under these conditions was only 10%. The role of ozone was spectroscopically proven to oxidize ferrous ions to form ferric ions, which are effective oxidizers of chalcopyrite. The presence of copper in solution in the form of cuprous (Cu⁺) ions was proven electrochemically. The increased copper extraction in the solution was caused by the stabilization of cuprous ions by isopropanol. The limiting stage of the process was the chemical reaction on the chalcopyrite surface with the activation energy of 73.4 kJ mol⁻¹. Full article

Cuprous oxide is a semiconductor with potential for use in photocatalysis, sensors, and photovoltaics. We used ion implantation to modify the properties of Cu₂O oxide. Thin films of Cu₂O were deposited with magnetron sputtering and implanted with low-energy Cr ions of different dosages. The X-ray diffraction method was used to determine the structure and composition of deposited and implanted films. The optical properties of the material before and after implantation were studied using spectrophotometry and spectroscopic ellipsometry. The investigation of surface topography was performed with atomic force microscopy. The implantation had little influence on the atomic lattice constant of the oxide structure, and no clear dependence of microstrain or crystalline size on the dose of implantation was found. The appearance of phase change was observed, which could have been caused by the implantation. Ellipsometry measurements showed an increase in the total thickness of the sample with an increase in the amount of implanted Cr ions, which indicates the influence of implantation on the properties of the surface and subsurface region. The refractive index n, extinction coefficient k, and absorption coefficient optical parameters show different energy dependences related to implantation dose. Full article