Increasing Copper Content Research Articles

Copper Catalysts Anchored on Cysteine-Functionalized Polydopamine-Coated Magnetite Particles: A Versatile Platform for Enhanced Coupling Reactions

Cysteine plays a crucial role in the development of an efficient copper-catalyst system, where its thiol group serves as a strong anchoring site for metal coordination. By immobilizing copper onto cysteine-modified, polydopamine-coated magnetite particles, this advanced catalytic platform exhibits exceptional stability and catalytic activity. Chemical modification of the polydopamine (PDA) surface with cysteine enhances copper salt immobilization, leading to the formation of the Fe3O4@PDA-Cys@Cu platform. This system was evaluated in palladium-free, copper-catalyzed Sonogashira coupling reactions, effectively catalyzing the coupling of terminal acetylenes with aryl halides. Additionally, the Fe3O4@PDA-Cys@Cu platform was employed in click reactions, confirming the enhanced catalytic efficiency due to increased copper content. The reusability of the platform was further investigated, demonstrating improved performance, especially in recyclability tests in click reaction, making it a promising candidate for sustainable heterogeneous catalysis.

A Novel Elastomeric Dielectric Materials: Natural Rubber/Copper-Modified Activated Carbon

In this research, a new elastomeric dielectric material is created by integrating natural rubber (NR) with activated carbon derived from coconut shells that has been modified with copper (Ac-Cu). Here, The copper content, ranging from 0 to 2%, was meticulously examined on the AC surface through a reduction technique from copper (II) to copper (0), with the Ac-Cu concentration fixed at 15 parts per hundred of rubber (phr). Systematic investigations into the effects of the additive were conducted across various parameters, encompassing optimum curing time (t90), density, crosslink density, mechanical properties, morphology, and dielectric properties. Results revealed a notable influence of copper on the curing process, resulting in decreased cure time, and a corresponding decrease in crosslink density as the copper content increased. Interestingly, copper incorporation demonstrated a positive impact on mechanical properties. Dielectric property analysis further confirmed a direct effect of increasing copper content on the frequency range of 0.85 to 1.15 GHz. This work not only introduces a pioneering dielectric material but also provides crucial insights into the nuanced effects of copper modification, offering avenues for tailored material design in the realm of enhanced dielectric applications.

Effect of primary copper metabolism disturbance on elemental, protein, and lipid composition of the organs in Jackson toxic milk mouse.

Toxic milk (txJ) is an autosomal recessive mutation in the Atp7b gene in the C3H/HeJ strain, observed at The Jackson Laboratory in Maine, USA. TxJ mice exhibit symptoms similar to those of human Wilson's disease (WD). The study aimed to verify organ involvement in a mouse model of WD. TxJ mice and control animals were sacrificed at 2, 4, 8, and 14months of age. Total X-ray Fluorescence Spectroscopy (TXRF) was used to determine the elemental concentration in organs. Tissue chemical composition was measured by Fourier Transform Infrared Spectroscopy (FTIR). Additionally, hybrid mapping of FTIR and microXRF was performed. Elevated concentrations of Cu were observed in the liver, striatum, eye, heart, and duodenum of txJ mice across age groups. In the striatum of the oldest txJ mice, there was lower lipid content and a higher fraction of saturated fats. The secondary structure of striatum proteins was disturbed in txJ mice. In the livers of txJ mice, higher concentrations of saturated fats and disturbances in the secondary structure of proteins were observed. The concentration of neurofilaments was significantly higher in txJ serum. The distribution of Cu deposits in brains was uniform with no prevalence in any anatomic structure in either group, but significant protein structure changes were observed exclusively in the striatum of txJ. In this txJ animal model of WD, pathologic copper accumulation occurs in the duodenum, heart, and eye tissues. Increased copper concentration in the liver and brain results in increased saturated fat content and disturbances in secondary protein structure, leading to hepatic injury and neurodegeneration.

Fundamentals of copper(II) adsorption on phyllosilicate minerals relevant to crud formation in solvent extraction from heap leach liquors

Because of the common presence of different silicate minerals, like kaolinite, montmorillonite and muscovite as gangue minerals in the beneficiation of copper oxide ores, the interaction between copper(II) ions in solution and each of these minerals is a field of strong interest, considering their implications on the aggregation of these minerals in the extreme pH conditions typical of hydrometallurgical unit operations for copper production. After copper adsorption isotherms determination at pH 2 and 4, specific adsorption data were fitted to both Langmuir and Freundlich models. It was found that adsorption is systematically larger at pH 4, and that montmorillonite is the mineral that displays a larger adsorption capacity, as in principle expected by its larger cation exchange capacity, CEC. A good fitting to the Langmuir model was obtained for the three samples, and montmorillonite also appears to conform to Freundlich isotherm predictions, as the tested concentrations of copper(II) do not allow to reach saturation. Furthermore, some desorption is measured for kaolinite and muscovite at the highest copper concentrations, probably because of significant interactions between the adsorbed ions. No such desorption was detected in montmorillonite samples. An XPS analysis of the surfaces of the three minerals suggests that copper adsorption in kaolinite is not associated to a cation exchange process but rather to electrostatic interactions between silica-like faces of the clay. In contrast, ionic exchange of structural calcium (for montmorillonite) or potassium (in the case of muscovite) seems to be the predominant mechanism of Cu(II) adsorption in the other two samples. Electrophoretic mobility determinations agree with this hypothesis: the mobility (always negative, with no traces of charge inversion) decreases in absolute value when kaolinite particles are in contact with solutions of increasing copper concentration at pH 2 or pH 4. On the other hand, the electrophoretic mobility values of muscovite and montmorillonite showed a weak pH and copper concentration dependence, a result that matches well with the ion exchange processes detected in the XPS measurements.

Износостойкость и коррозионное поведение Cu-Ti-покрытий в растворе SBF

Introduction. Currently, titanium and its alloys have become the most popular metal implantable biomaterials. However, the main disadvantage of titanium alloys is low wear resistance due to high viscosity. It is known that copper-titanium coatings effectively improve the antibacterial properties of titanium alloy and at the same time increase its wear resistance. Purpose of the work is to study the effects of a solution simulating body fluid on corrosion properties, friction coefficient and the wear of copper-titanium coatings obtained by electrospark deposition method of the Ti-6Al-4V alloy. Method. A non-localized electrode consisting of copper and titanium granules in various ratios was used to form copper-titanium coatings on a titanium alloy by electrospark deposition. The structure of the coatings was examined using a DRON-7 X-ray diffractometer in Cu-Kα radiation and an X-max 80 energy dispersive spectrometer. The antibacterial activity of the deposited Cu-Ti coatings was studied on a non-pathogenic gram-negative culture of Escherichia coli. Polarization tests in SBF solution were carried out using a P-40X potentiostat with an impedance measurement module. The metal content in the SBF solution after immersion of the samples was measured using an ICP-MS 2000 mass spectrometer. The tribological characteristics of the coatings according to the ASTM G99-17 standard using the “ball-on-disk” scheme with sliding friction in the SBF solution at loads of 10 and 25 N were examined. Results and discussions. It is shown that the bactericidal activity of Cu-Ti coated samples to a non-pathogenic culture of Escherichia coli increased monotonously with an increase in copper content. With copper concentration increasing, the corrosion current density of the coatings increased from 3.455 to 17.570 μA/cm2. It is shown that the SBF solution accelerates the wear of a titanium alloy many times over due to its interaction with the electrolyte via the oxidative wear mechanism. The use of Cu-Ti coatings allows reducing the friction coefficient and greatly decreasing the wear of Ti-6Al-4V alloy in the presence of an electrolyte.

350 Awardee Talk: Beef cattle mineral nutrition: What do we know and where do we go from here

Abstract Trace minerals are pivotal in enhancing cattle growth and ensuring profitability in beef production. Historically, supplementation strategies have aimed at preventing deficiencies, significantly improving growth and reproductive performance. However, as cattle breeding has evolved to achieve remarkable growth rates, the challenges related to health and stress during the feeding period have intensified. This presentation explores refined trace mineral recommendations, focusing on zinc’s “stress requirement” for cattle undergoing transit and health challenges, and its impact on performance. The segmented nature of the beef industry, necessitating multiple transports, induces physiological stress and oxidative stress, highlighting the need for tailored mineral supplementation. Further, when recognizing feedlot cattle as the high-performing athletes they are, the potential benefits of adjusted trace mineral concentrations become apparent. Preliminary findings suggest that optimal zinc concentrations may exceed current National Academies of Sciences, Engineering, and Medicine (NASEM) 2016 recommendations, whereas for other minerals like copper and manganese, the existing guidelines remain appropriate. This presentation will explore the differential effects of increasing dietary zinc and copper in conjunction with various growth-promoting technologies. Preliminary data indicates that increasing zinc concentrations can linearly enhance average daily gain (ADG) and hot carcass weight (HCW), especially when using potent anabolic implants, while the response to increased copper concentrations exhibits a more quadratic relationship with performance. Building upon the foundational work of pioneering researchers in the field of mineral nutrition, this presentation advocates for the continuous refinement and optimization of trace mineral supplementation strategies. By integrating cutting-edge technologies and fostering collaborative research efforts, we aim to further enhance the sustainability of the beef industry. A deeper understanding of trace mineral requirements in the face of modern production challenges will pave the way for more precise and effective nutritional strategies.

Performance and biotoxicity of electro-Fenton treatment of bisphenol A: Evaluation of copper recovered from microbial fuel cell cathodes for subsequent catalytic applications

A three-tank microbial fuel cell (MFC) is successfully constructed to achieve electromigration and is used in the electro-Fenton process to treat bisphenol A (BPA). The MFC system exhibits excellent mobility and efficiently aggregates Cu+ to the cathode. Under optimal operating conditions, the MFC achieves a maximum power density of 31.4 mW/m2, which is a 3.4-fold increase over that at 0.5 kΩ. Increasing the external resistance increased the MFC power output (ca 1.5 times) and copper ion migration (ca 4.6 times) while reducing the internal resistance of the system (ca 25.3 %). Surface analysis of the cathode carbon cloth shows a 5.5-fold increase in copper content at 1 kΩ over that at 0.5 kΩ. This also increases the oxygen reduction reaction rate, thereby increasing the H2O2 yield by 1.5 times. The recovered copper cathode at 1 kΩ exhibits the best catalytic degradation of BPA, removing 99.7 % of BPA in 180 min, increasing 1.4 and 1.8 times that obtained at 1.5 and 0.5 kΩ, respectively. The optimal operating conditions significantly increased the abundance of electrochemically active bacteria (Azospirillaceae) (3.2 %−41.7 %), indicating that the optimized MFC is favorable for the rapid acclimatization of electrochemically active bacteria.

The influence of Cu on the microstructure and properties of TC4/Q345 high-entropy joints by laser welding

FeCoNiCrCu high-entropy alloy (HEA) and Cu foils were utilized as the intermediate layer to conduct laser welding of TC4 titanium alloy and Q345 steel. Welding is performed by adding single HEA and Cu/HEA double foils as interlayer respectively. We conducted in-depth studies on the microstructure and mechanical properties of the joint by stereomicroscopy, metallographic microscope, scanning electron microscope (SEM), micro-area X-ray diffraction (XRD), nanoindentation, electron backscatter diffraction (EBSD), and tensile testing. The results indicate that the position of the copper foil significantly affects the microstructure and performance of the joint. When the copper foil is on the TC4 side, its lower melting point causes a deeper keyhole, resulting in a narrower weld bead and then reduced content of Fe and Ti in the weld. Simultaneously, the increased proportion of Cu in the weld significantly enhances the content of Cu-rich phases. In the weld zone, we observed freely distributed Cu-rich phases and Ti-rich phases generated along the interface. Under tensile loads, cracks primarily initiate and propagate along the Cu-rich phases, leading to typical delamination on the fracture surface. With the copper foil on the TC4 side, due to the increased copper content in the microstructure, the hardness of the interface between the titanium alloy and the weld decreases, while the joint exhibits the highest tensile strength, reaching a maximum of 417 MPa.

PSXI-16 Increased copper concentrations in liver and duodenum tissues in Rambouillet-crossbred sheep receiving copper supplementation

PSXI-16 Increased copper concentrations in liver and duodenum tissues in Rambouillet-crossbred sheep receiving copper supplementation

Impact of the copper load on the performance of Cu/UiO-67 in CO2 hydrogenation to ethanol at atmospheric pressure

CO2 hydrogenation to ethanol could be a potential approach to reduce dependence on fossil resources, but faces challenges related to product selectivity and catalyst stability. MOFs, particularly UiO-67, acting as a support for copper catalysts can contribute to overcoming these limitations by stabilizing intermediates, creating interfaces that protect active sites against deactivation and potentially generating synergistic effects that favor the formation of the C-C bond. In this scenario, the present work aims to synthesize Cu/UiO-67 for application in the CO2 hydrogenation to ethanol at atmospheric pressure. The impact of the copper loading (5–60 wt%) on the catalyst physical properties and ethanol productivity was evaluated. Using XRD, N2 physisorption, TEM-EDS, FTIR and H2-TPR, it was possible to confirm the maintenance of the UiO-67 structure, which begins to deform with increasing copper content. Catalytic results showed that ethanol, methanol, propanol, carbon monoxide, and acetaldehyde have been produced. The selectivity of alcohols is related to the amount of copper, decreasing at high contents, indicating the importance of active sites interaction with SBUs units in alcohols formations.

Metagenomic insights into the prokaryotic communities of heavy metal-contaminated hypersaline soils

Saline soils and their microbial communities have recently been studied in response to ongoing desertification of agricultural soils caused by anthropogenic impacts and climate change. Here we describe the prokaryotic microbiota of hypersaline soils in the Odiel Saltmarshes Natural Area of Southwest Spain. This region has been strongly affected by mining and industrial activity and feature high levels of certain heavy metals. We sequenced 18 shotgun metagenomes through Illumina NovaSeq from samples obtained from three different areas in 2020 and 2021. Taxogenomic analyses demonstrate that these soils harbored equal proportions of archaea and bacteria, with Methanobacteriota, Pseudomonadota, Bacteroidota, Gemmatimonadota, and Balneolota as most abundant phyla. Functions related to the transport of heavy metal outside the cytoplasm are among the most relevant features of the community (i.e., ZntA and CopA enzymes). They seem to be indispensable to avoid the increase of zinc and copper concentration inside the cell. Besides, the archaeal phylum Methanobacteriota is the main arsenic detoxifier within the microbiota although arsenic related genes are widely distributed in the community. Regarding the osmoregulation strategies, “salt-out” mechanism was identified in part of the bacterial population, whereas “salt-in” mechanism was present in both domains, Bacteria and Archaea. De novo biosynthesis of two of the most universal compatible solutes was detected, with predominance of glycine betaine biosynthesis (betAB genes) over ectoine (ectABC genes). Furthermore, doeABCD gene cluster related to the use of ectoine as carbon and energy source was solely identified in Pseudomonadota and Methanobacteriota.

Tuning structural and electrical properties of Co-precipitated and Cu-incorporated nickel ferrite for energy applications

Abstract The Ni1−x Cu x Fe2O4 (where x = 0, 0.05, 0.10, 0.15) nano ferrite powder was synthesized through chemical co-precipitation method, NaOH and acid oleic as raw materials. The XRD patterns confirmed the spinal structure phase purity of materials. XRD results showed that lattice parameter decreases with the increase of copper concentration by increasing copper concentration in the parent material. Scanning electron microscopy (SEM) was used to determine the morphology and particle size. SEM analysis indicated that all the samples are in nano size and homogeneous. AC electrical properties of nanoparticles were investigated by employing impedance spectroscopy. The real and the imaginary parts of impedance, permittivity, modulus along with the real part of ac conductivity, and tan delta were measured and analyzed for all synthesized samples in 1 Hz to 7 MHz for different voltages at 300 K.

Copper doped hybrid 2D ZnO-stearic acid nanocomposite for boosting photocatalytic degradation of organic pollutants under simulated solar light

This study explores the enhancement of photocatalytic performance in 2D ZnO-stearic acid (SA) composites through copper (II) doping. Materials containing 1–10 mol% Cu (II) were synthesized by coprecipitation and characterized using X-ray photoelectron spectroscopy, electron paramagnetic resonance, UV–visible and vibrational spectroscopies, as well as X-ray diffraction. These analyses confirmed the formation of single-phase composites with structures resembling the ZnO-SA precursor, but exhibiting discrete Zn/Cu doping, forming Zn1-xCuOx-SA materials. Scanning electron microscopy and Energy dispersive X-ray spectroscopy analysis revealed layered structure and the elemental compositions of the samples. High-resolution transmission electron microscopy (HR-TEM) images confirm the layered morphology of the Zn0.95Cu0.05O-SA sample, underscoring its two-dimensional material characteristics. Absorption band edge of the undoped hybrid ZnO is centered in the UVA zone, while copper-doped samples expanded into the visible range. Photoluminescence (PL) spectra exhibit multiple emission peaks related to defects within ZnO host. An intensity slight decrease in PL intensity is observed with increasing copper concentration, indicated a low recombination rate. Photoelectrochemical testing showed that Cu doping reduces charge recombination and increases current density, thereby improving photocatalytic degradation of pollutants such as indigo carmine and 4-chlorophenol under simulated sunlight. The optimally doped Zn0.95Cu0.05O-SA displayed significant efficiency improvements, degrading contaminants up to four times faster than the undoped composite and maintaining consistent performance over multiple cycles. Additional testing linked these photocatalytic improvements to enhanced charge separation and electron/hole transfer facilitated by Cu2+ ions, thereby boosting photocatalytic activity.

Experimental study of copper contamination in mechanical properties of residual soil under different concentration

Abstract Industrialization in modern society comes along with soil degradation and heavy metal pollution. The presence of heavy metals changes the geotechnical properties of soils, risking the sites with the possibility of contaminated soil. Heavy metal contaminants might alter the mechanical properties and soil behaviour leading to the effects on the structural integrity. The purpose of this research is to evaluate the mechanical properties of residual soil samples contaminated with different concentrations of copper. Disturbed residual soils were induced with copper in controlled environment. Six samples were prepared, including a control sample consisting of a CuSO4 solution with a spectrum of concentrations ranging from 0 mg/L to 4000 mg/L, with interval 500 mg/L. The results of the experiment revealed that increasing the concentration led to an increase in the maximum dry density, while the optimum moisture content showed an opposite response. The increase in copper concentration resulted in a dynamic shift in the plastic limit, a decrease in the liquid limit and pH, making the soil naturally acidic. The output shows aid in the development of appropriate soil management strategies and remediation techniques to mitigate the adverse effects of copper contamination on soil quality and environmental sustainability.

Nutritional Quality and Antioxidant Properties of Roselle-Tiger Nut Beverage

Background: A beverage is a liquid prepared from cereals, grains and leaves/calyxes for human consumption. Beverages are classified into alcoholic and non-alcoholic beverages. Objective: The study evaluated the nutritional quality and antioxidant properties of Roselle-tiger nut beverage. Methods: Roselle-tiger nut beverage was produced from the control samples roselle and tiger nut (% v/v) using the ratios 100:0 Roselle beverage, 0:100 tiger nut beverage and 80:20 Roselle-tiger nut beverage. Subsequently, Proximate, mineral, phytochemical compositions, antioxidants properties and sensory properties were determined using established methods. Results: There was an elevation in protein (16.29±2.39a) carbohydrate (11.08±9.59a), crude protein (16.29±2.39a) and ash content (3.09±0.56a) but a decrease in moisture and crude fat content. Also, an increase in Sodium (0.09±0.01b), Zinc (0.21±0.00b) and Copper (0.09±0.00b) content with a decrease in Potassium, Phosphorus, Manganese, Magnesium, Calcium and Iron levels. For phytochemical compositions, an increase in flavonoids (1.73±0.43a), saponins (1.25±0.75a) and alkaloids (1.36±0.13a) contents with a decrease in tannins, oxalates and phytate contents was observed. There was an elevation in free radical scavenging activity (0.36±0.00ab) and ferric reducing power (0.32±0.00c) but a decrease in hydroxyl scavenging activity and metal chelating ability. Sample MNP836 of Roselle-tiger nut beverage was the most preferred by panelists for appearance (8.10), taste (8.24), flavor (8.38), mouth feel (8.38) and overall acceptability (8.48). Conclusion: Substitution of roselle beverage with 20% tiger nut beverage improved the nutritional quality of roselle-tiger nut beverage.

A fluorescent functionalized PET fabric with dual-response to aqueous copper and pH

A fluorescent functional PET fabric for effective aqueous copper detection was developed. Eu(TTA)3·2H2O complex was prepared by the solvothermal method and subsequently PET fluorescent nonwoven fabrics were prepared by coordinating the complexes with PET nonwoven fabrics grafted with acrylic acid.The chemical structure and microscopic morphology of the fluorescent nonwovens were analyzed, and the effects of different experimental conditions (grafting rate, reaction time, and fluorescent complex concentration) on the fluorescence properties of the materials were investigated. Under optimal experimental conditions, the fluorescent nonwoven fabric exhibited a fluorescence intensity of 2.1 × 105 a.u. and a quantum yield of 6.35%. Additionally, the fluorescence intensity of the fluorescent nonwoven fabric decreased with the increase of aqueous copper concentration, and the quenching effect could be described by the Stern-Volmer equation. Furthermore, adjusting the pH of the aqueous copper at a fixed concentration revealed a linear relationship between the fluorescence intensity and pH. These observations demonstrate a dual response of the fluorescent nonwoven fabric to both aqueous copper and pH, enabling its potential application in the detection of both analytes.

Phase Transformation of Arsenic, Antimony and Lead in High-Grade Copper Matte Converting

The duration of the high-grade matte converting process is short, the amount of slag is small, and it is difficult for the original impurity removal operation in the low-grade matte converting process to meet the current production demand. Because the removal method for impurity elements during high-grade matte converting is unclear, the phase transformation of impurity elements during this process is investigated in this study. The results show that arsenic exists mainly in the form of FeAsO4 and As2O5, antimony in the form of Sb and Sb2O5, and lead in the form of PbS and PbO in high-grade matte. During the converting process, arsenic and antimony mainly exist in the melt in the form of oxides and gradually aggregate into large particles with increasing copper content in the melt. Lead exists in matte in the form of PbS until the end of the converting process, and PbS is not completely oxidized until the matte converted to blister copper phase. The phase transformation characteristics of copper, iron, sulfur and impurity elements in the process of high-grade matte converting were revealed. This study provides a theoretical reference for the formulation of an efficient impurity removal scheme for the converting process.

Si3N4 preparation from photovoltaic kerf loss silicon waste by copper collaborative nitriding method

In this work, Si3N4 powders were prepared by collaborative direct nitriding method from photovoltaic kerf loss silicon waste. The catalytic effect of copper (Cu) on the direct nitriding reaction of photovoltaic Si waste and the morphologies of the nitriding products were investigated. The quantitative analysis of XRD results and thermogravimetric results demonstrate that Cu significantly reduces the initial nitriding temperature, and Cu has a positive effect on the nitriding of silicon waste. At 1300 °C, the sample without Cu had almost no nitriding reaction, while the total conversion rate of kerf loss waste Si was 100 %, and the yield of (α+β) Si3N4 was up to 79.2 % with 8 wt% Cu additive. The thermodynamic analysis of the Si-O-N-Cu and nitriding process was carried out by FactSage software. Moreover, the morphologies of the nitride products were observed by SEM. The addition of copper promoted the generation of Si3N4 nanorods, and the number and diameter of α-Si3N4 nanorods increased with the increase in copper content. Three reaction mechanisms of Si nitridation were discussed. This work provides a feasible method to reuse and recycle the kerf lost silicon waste.

Bioremediation potential of microalgae for copper ion from wastewater and its impact on growth and biochemical contents: equilibrium isotherm studies

The use of microalgae to remediate heavy metal-contaminated wastewater has attracted more and more interest. In this investigation, the green microalgae Chloroidium ellipsoideum and Desmodesmus subspicatus were used to study copper uptake from nutrient media and its effect on algal growth and metabolism. The growth of C. ellipsoideum and D. subspicatus generally decreased with increasing copper concentrations. There was a decrease in the carbohydrate content of C. ellipsoideum, but an increase was observed in D. subspicatus by treatment with various copper concentrations. Low concentrations of copper helped to increase the protein content of C. ellipsoideum, but a decline in protein content was reported for D. subspicatus. By increasing the copper concentrations, an increase in the free amino acids and a decrease in the total lipid content of C. ellipsoideum and D. subspicatus were recorded. At 0.1 mgl–1 copper concentration, pH of 6.8, and algal dose of 1 g L−1, the maximum biosorption capacity of C. ellipsoideum was 0.398 mg g−1, corresponding to the maximum reduction of 68.66% of Cu2+, and 0.396 mg/g for D. subspicatus, corresponding to the maximum reduction of 59.52%. The Langmuir, Freundlich, Temkin and Dubinin–Radushkevich models were applied to describe the isothermal biosorption of Cu2+ ions in studied algae. The Dubinin–Radushkevich model indicated that the copper biosorption mechanism was physical in nature. Cu2+ has a greater affinity for D. subspicatus than C. ellipsoideum, suggesting that C. ellipsoideum was relatively more resistant to Cu2+ toxicity than D. subspicatus. Moreover, FT-IR analysis revealed that carboxyl, amide, amino, carbonyl, hydroxyl, methyl and alkyl groups were the key groups responsible for the biosorption process. Therefore, D. subspicatus and C. ellipsoideum are efficient biosorbents for Cu2+ and can be used as biosorbents for heavy metals removal from wastewater.

Preparation of Tunable Cu−Ag Nanostructures by Electrodeposition in a Deep Eutectic Solvent

AbstractThe green transition requires new, clean, inexpensive, and sustainable strategies to prepare controllable bimetallic and multimetallic nanostructures. Cu−Ag nanostructures, for example, are promising bimetallic catalysts for different electrocatalytic reactions such as carbon monoxide and carbon dioxide reduction. In this work, we present the one‐step preparation method of electrodeposited Cu−Ag with tunable composition and morphology from choline chloride plus urea deep eutectic solvent (DES), a non‐toxic and green DES. We have assessed how different electrodeposition parameters affect the morphology and composition of our nanostructures. We combine electrochemical methods with ex‐situ scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDS), and X‐ray photoelectron spectroscopy (XPS) to characterize the nanostructures. We have estimated the electrochemically active surface area (ECSA) and roughness factor (R) by lead underpotential deposition (UPD). The copper/silver ratio in the electrodeposited nanostructures is highly sensitive to the applied potential, bath composition, and loading. We observed that silver‐rich nanostructures were less adherent whereas the increase in copper content led to more stable and homogenous films with disperse rounded nanostructures with tiny spikes. These spikes were more stable when the deposition rate was fast enough and the molar ratio of Cu and Ag was no greater than approximately two to one.