Mechanism Of Cu Research Articles

Insight into efficient degradation of pentacyclic and hexacyclic sulfonamide antibiotics by synthetic trivalent copper: Performance and mechanism

High valent metal species, including Mn(III), Fe(IV) and Cu(III), have been identified as key intermediates in the degradation of pollutants in many advanced oxidation processes. However, unlike Mn(III) and Fe(IV), the current exploration of the reaction activity and selective oxidation mechanism of Cu(III) towards pollutants with different structures is still quite limited. Herein, the copper(III) periodate was synthesized to investigate the reactivity towards six sulfonamide antibiotics (SAs) including typical two pentacyclic structures (sulfamethoxazole (SMX) and sulfathiazole (STZ)) and four hexacyclic structures (sulfadiazine (SDZ), sulfamerazine (SMR), sulfamonomethoxine (SMM) and sulfapyridine (SPD)). The results indicated that all SAs almost completely removed by Cu(III) system after 10 min with the molar ratio of approximately 3:1 (Cu(III):SAs) and Cu(III) direct oxidation played the most important role. SAs with 6-ring substituents were more readily degraded by Cu(III) than SAs with 5-ring substituents, and the presence of electron-rich group such as -CH3 and -S in ring substituent increased the reactivity towards Cu(III). The introduction of coexisting anions (Cl−, SO42− and HCO3−) hardly affected the degradation of SAs by Cu(III) oxidation, while the addition of HA to some extent inhibited SAs degradation. The solution pH greatly affected the degradation of SAs by Cu(III) and the removal efficiencies of SAs roughly followed the rule of neutral > acidic > alkaline. The degradation mechanism of SAs with 5-ring and 6-ring substituents in Cu(III) system mainly included amino nitration, self-coupling, hydroxylation, S-N cleavage in SAs with 5-ring substituents and SO2 extrusion in SAs with 6-ring substituents. Although the real water matrix inhibited the degradation of SAs to varying degrees, Cu(III) still played a satisfactory performance on SAs degradation especially for electron-rich structure.

Molecular dynamics study on the deformation mechanism of Cu–Zr/Al laminated composites

In this paper, molecular dynamics simulation was used to investigate the micromechanical behavior of the Cu–Zr/Al composite interface after rapid solidification. The effects of different Zr contents and different strain rates on the tensile strength of the Cu–Zr/Al composite interface were investigated. The results show that the tensile strength of the composite plate increased and then decreased with the increase of Zr content, and the tensile strength is the highest when the Zr content is 0.33 wt%. It was found that the plastic deformation process of the composite model at different strain rates is similar, which is divided into three stages: the expansion of stacking faults in the Cu–Zr/Al solid solution, the expansion of stacking faults successively in the Al and Cu–Zr alloy layers, and the spreading of cross - stacking faults. But the greater the strain rate is, the slower the stacking faults fracture is. So the composite model with different strain rates had different fracture modes during the tensile fracture process. When the strain rate is 0.01 ps−1 and 0.001 ps−1, it is a ductile fracture, while when the strain rate is 0.0001 ps−1, it is a brittle fracture.

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.

Light emission from multiple self-trapped excitons in one-dimensional Ag-based ternary halides

Abstract Ternary metal halides based on Cu(I) and Ag(I) have attracted intensive attention in optoelectronic applications due to their excellent luminescent properties, low toxicity, and robust stability. While the self-trapped excitons (STEs) emission mechanisms of Cu(I) halides are well understood, the STEs in Ag(I) halides remain less thoroughly explored. This study explores the STE emission efficiency within the A 2AgX 3 (A = Rb, Cs; X = Cl, Br, I) system by identifying three distinct STE states in each material and calculating their configuration coordinate diagrams. We find that the STE emission efficiency in this system is mainly determined by STE stability and influenced by self-trapping and quenching barriers. Moreover, we investigate the impact of structural compactness on emission efficiency and find that the excessive electron–phonon coupling in this system can be reduced by increasing the structural compactness. The atomic packing factor is identified as a low-cost and effective descriptor for predicting STE emission efficiency in both Cs2AgX 3 and Rb2AgX 3 systems. These findings can deepen our understanding of STE behavior in metal halide materials and offer valuable insights for the design of efficient STE luminescent materials. The datasets presented in this paper are openly available in Science Data Bank at https://doi.org/10.57760/sciencedb.12094.

Insights into the individual and combined effects of Cu(Ⅱ) and Ni(Ⅱ) on anammox: Nitrogen removal performance, enzyme activity and microbial community

Anaerobic ammonium oxidation (anammox) is an efficient and economical nitrogen removal process for treating ammonium-rich industrial wastewaters. However, Cu(Ⅱ) and Ni(Ⅱ) present in industrial wastewaters are toxic to anaerobic ammonium-oxidizing bacteria (AnAOB). Unfortunately, the effects of Cu(Ⅱ) and Ni(Ⅱ) on anammox have not been thoroughly investigated, especially when Cu(Ⅱ) and Ni(Ⅱ) coexist. This work comprehensively investigated the individual and combined effects of Cu(Ⅱ) and Ni(Ⅱ) on anammox and revealed the inhibitory mechanisms. With the influent NH4+-N and NO2−-N concentration of 230 and 250 mg L−1, the inhibition thresholds on anammox are 2.00 mg L−1 Cu(Ⅱ), 1.00 mg L−1 Ni(Ⅱ) and 1.00 mg L−1 Cu(Ⅱ) + 1.00 mg L−1 Ni(Ⅱ), and higher Cu(Ⅱ) or Ni(Ⅱ) concentrations resulted in sharp deteriorations of nitrogen removal performance. The inhibition of Ni(Ⅱ) on anammox was mainly attributed to the adverse effect on NiR activity, while the inhibition mechanism of Cu(Ⅱ) seemed to be unrelated to the four functional enzymes, but associated with disruption of cellular and organellar membranes. The behavior of extracellular polymeric substances (EPS) contributed to the antagonistic effect between Cu(Ⅱ) and Ni(Ⅱ) on anammox. In addition, the niche of Candidatus Brocadia and Candidatus Jettenia shifted under the Cu(II) and Ni(II) stress, and Candidatus Jettenia displayed greater tolerance to Cu(II) and Ni(II) stress. In conclusion, this research clarified the combined effect and the inhibitory mechanism of multiple heavy metals on anammox, and provide the guidances for anammox process application in treating high-ammonium industrial wastewaters containing heavy metals.

Experimental and Computational Investigation of Salicylhydroxamic Acid as a Corrosion Inhibitor for Copper in Alkaline Solutions

Inhibitors, as indispensable components in chemical mechanical polishing (CMP) slurries, have a significant impact on inhibiting copper (Cu) corrosion and enhancing post-polishing surface quality. However, one of the major challenges in CMP lies in unraveling the microscopic corrosion inhibition mechanism of Cu. This work focuses on investigating the impact of an inhibitor, salicylhydroxamic acid (SHA), on the static etching rate (SER), electrochemical parameters, and surface morphology of Cu. The experimental findings demonstrate that SHA significantly decreases the SER and corrosion current density of Cu, while notably improving the Cu surface quality. The corrosion inhibition mechanisms of SHA on Cu are revealed through adsorption isotherm models, contact angle analysis, electrochemical impedance spectroscopy, and computational chemistry method. The benzene ring, oxime group, and O1 atom of SHA exhibit significant chemical reactivity, facilitating the preferential adsorption of SHA on Cu in a parallel orientation, thereby forming a hydrophobic protective film on the Cu surface. This process hinders the interaction between corrosive solutions and Cu, therefore SHA exhibits excellent corrosion inhibition performance on Cu. These findings hold great importance in gaining a deeper comprehension of the corrosion inhibition process of Cu, and provide guidance for designing more efficient inhibitors.

Fractal Growth Regulation and Mechanism of Copper Dendrite by Micro‐point Electrode Electrodeposition

AbstractThe behavior of fractal growth based on copper metal was examined by micro‐point electrode electrodeposition. On this basis, the process and morphological characteristic of Cu fractal growth can be controlled by changing the electrodeposition time, current and concentration of Cu2+. The growth of snowflake Cu dendrites is confined to the two‐dimensional plane of the paper base to monitor the fractal structural changes. The electrodeposition process of snowflake Cu dendrites is deeply regulated by exploring the changing trend of fractal dimension. To further understand the fractal growth mechanism of Cu, the electro‐driven centripetal migration and random migration of ions are introduced in the traditional diffusion‐limited aggregation model. The simulated fractal patterns successfully correspond with the experimental results. The results are helpful to explore the fractal growth characteristics and dynamic mechanism of the electrodeposited copper dendrites, which lay a foundation for controlling the growth of the electrodeposited metal dendrites.

The sulfurization precipitation and competition mechanisms of Cu(II) and As(V) in electrolyte towards efficient recovery of copper

The sulfide precipitation has been widely used to recover Cu(II) and remove As(V) in copper smelting electrolyte based on the Cu(II)-As(V) separation. However, the recovery efficiency was undesirable due to the inaccurate control of process parameters. It was necessary to investigate the process and mechanisms of sulfurization precipitation for accurate adjustment. Herein, under the single and mixed solutions of Cu(II) and As(V), the process parameters were investigated and the precipitation mechanisms were explored. And when using actual electrolytes, the corresponding sulfurization process and mechanisms were also revealed. The sulfurization results of single component solutions suggested that Cu(II) was rapidly precipitated in one step, but As(V) firstly generated intermediate, then it was gradually reduced to As(III) for a longer time and quickly precipitated in the form of amorphous. This phenomenon caused the significantly faster removal speed of Cu(II) than that of As(V). For their mixed solutions, only a small amount of As(V) were removed by adsorbing the precipitate at the low S/Cu molar ratios (RS/Cu), and Cu(II) and As(V) could achieve a good separation. Simultaneously, it revealed that the sulfidation competitive mechanisms were related to the solubility product constant (Ksp) and initial As(V) concentrations. In addition, the similar rules were also observed in actual electrolytes. Moreover, under RS/Cu = 1.2 and reaction time of 10 min, the arsenic content of sulfide precipitates in the actual electrolyte was less than 2.5%, which showed a great separation also could be obtained for the actual electrolyte. This result met the requirement of Cu(II) recovery. It can provide a good reference for adjusting sulfidation parameters in the actual process to achieve efficient copper recovery, reduce the production of hazardous waste containing arsenic at the source and realize the cleaner production of copper smelting system.

Effectively enhanced photocatalytic hydrogen production performance of novel noble metal-free Cu(OH)2/MoSe2-g-C3N4 ternary nanocomposite under visible light irradiation

The present work presents a novel copper hydroxide-molybdenum diselenide-carbon nitride (3 % Cu(OH)2/MoSe2-g-C3N4, (3CM-CN)) ternary nanocomposite catalyst. This catalyst was synthesized using a three-step process: hydrothermal synthesis, ball milling, and wet impregnation. The focus of this research is on the hydrogen generation (H₂) capabilities of this novel material. The catalyst was extensively characterized using various analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible (UV–Vis) spectroscopy, photoluminescence (PL) spectroscopy, and X-ray photoelectron spectroscopy (XPS), resulting in a comprehensive understanding of its structure, morphology, optical properties, and surface composition. The catalytic activity and mechanism of Cu(OH)2/MoSe2-g-C3N4 composites were investigated. The ternary nanocomposite catalyst significantly enhanced hydrogen production, achieving rates 7.7 times greater than g-C3N4 and 4 times greater than 3 % Cu(OH)2/MoSe2 (3CM). Its maximum production reached an impressive 3012 µmol g−1 h−1. The analysis demonstrated a significant increase in active sites on the composite’s surface, accompanied by an increase in the composite-specific surface area to 73 m2/g. The development of a ternary nanocomposite led to a higher rate of catalyst production for hydrogen generation while simultaneously decreasing the rate of electron-hole recombination. It gave an innovative strategy for constructing highly efficient composite catalysts for hydrogen generation very effectively.

Conduction mechanisms analysis of ZrO2-based electrochemical metallization RRAM in different RESET modes

Resistive random access memory (RRAM) based on electrochemical metallization (ECM) is a promising candidate for future nonvolatile memory applications. This paper discusses the resistive switching (RS) behavior and conduction mechanism in the ZrO2-based ECM nonvolatile memory devices. Whether Cu or Ni is used as the top electrode, two different types of I-V curves are found in the same device, representing different RESET modes. The I–V fitting analysis suggests that one RRAM cell can follow two significantly different conduction mechanisms under two types of RESET modes. Under sudden rupture mode, conduction at the high resistance state (HRS) is dominated by a space-charge-limited conduction (SCLC). In contrast, under slow dissolution mode, the devices at HRS tend to show an Ohmic conduction mechanism. These phenomena can be explained by a physical model based mainly on Joule heat or electric field, which is related to the degree of dissolution and rupture of multiple conductive filaments (CFs). Furthermore, the electrical field simulation results based on the solid electrolyte theory by MATLAB further demonstrate the coexistence of two conduction mechanisms in Cu (or Ni)/ZrO2/Pt devices HRS. This paper provides a direction for better understanding the conversion mechanism of ECM RRAM, which is of great significance for the further development of RRAM.

Adsorption behavior and mechanism of Cu(II) by sodium alginate/carboxymethylcellulose/magnesium hydroxide (SC-MH) hydrogel

In the present work, an environmentally-friendly, reusable hydrogel ball characterized by its great adsorption capacity to Cu(II) was synthesized. The preparation of this hydrogel drew on sodium alginate (SA) and carboxymethyl cellulose (CMC) as primary composition elements. The endeavor brought novelty by ingeniously infusing it with slurry magnesium hydroxide (MH). The factors (pH, SC-MH amount, initial concentration, adsorption time) that are critical to adsorption were also investigated. FTIR, SEM-EDS and XPS were used to reveal the adsorption mechanism of Cu on SC-MH. The results show that the surface of SC-MH is rough, and there are a large number of gully-like structures conducive to adsorption, which are rich in hydroxyl and carboxyl groups. Under the optimum conditions, the maximum adsorption capacity reached 215.68 mg/g. Based on its high R2 value (0.999), the Langmuir model is determined to be the most appropriate for describing the adsorption behavior, indicating monolayer homogeneous adsorption. The kinetic data align well with the pseudo-second-order kinetic model. Furthermore, thermodynamic analysis reveals the adsorption process to be spontaneous and endothermic, as demonstrated by a negative ΔG and positive ΔH (38.8859 KJ/mol). The mechanism involves electrostatic attraction, chelation, Mg(OH)2 adsorption and ion exchange.

Strengthening mechanism of sub-nano Ni3P and Cu3P phases particles on the Pb–Sn bronze alloy

The influence of the sub-nano Ni3P and Cu3P phases on the microstructure, mechanical properties, and strengthening mechanism of Cu–20Pb–5Sn-xP (x = 0,0.05,0.1,0.3,0.5) alloy were discussed under the addition of P to obtain a new Pb–Sn bronze alloy applying for bimetallic cylinder block. The results showed that the tensile strength and hardness of the Pb–Sn bronze alloy increase with the P contents, while the elongation increased first and then decreased. The main strengthen mechanism was that sub-nano Ni3P and Cu3P phases dispersed in the matrix, hindering the movement of dislocations during deformation. Additionally, the grain refinement also contributed to the improvement of mechanical properties. The Ni3P phase is easier to form than the Cu3P phase. And it is easier to combine with the matrix and more stable. The Ni3P and Cu3P phases were studied by using different characterization techniques, such as OM, SEM, EDS, XRD, TEM and First-principles, Phase diagram calculation method. When P is added to the alloy, the Ni3P phase first appears in the alloy, and when the P content increases to more than 0.3 wt%, the Cu3P phase begins to appear. This is because the Ni3P phase is easier to form than the Cu3P phase and is more stable. Only after part of P reacts with Ni dissolved in copper to form Ni3P, the remaining P and Cu can form Cu3P.

An eco-friendly wheat straw adsorbent functionalized with mercaptopropionyl for the removal of Cu(II) from aqueous solution

A novel absorbent called mercaptopropionyl wheat straw (MPWS) was prepared through alkali pretreatment and mercaptopropionyl modification for efficient removal of Cu(II) from aqueous solutions. Single factor experiments were conducted to investigate various parameters affecting the adsorption of Cu(II) with MPWS. Adsorption experiments including kinetics, isotherms, thermodynamics, as well as various characterization methods were employed to discuss the mechanism of Cu(II) uptake by MPWS in this study. The results showed that MPWS exhibited high removal capacity for Cu(II), achieving a maximum removal efficiency of 97.28 % under optimal conditions: oscillation rate at 150 rpm, temperature at 303 K, duration at 2 h, pH value at 6.0, and initial concentration of Cu(II) at 100 mg/L. The fitting results indicated that pseudo-second-order kinetic model better described the experimental data while Freundlich model provided a better fit for isothermal data. Thermodynamic calculations confirmed that the adsorptive process was spontaneous and endothermic. Characterization techniques such as FTIR spectroscopy SEM imaging, and EDS analysis confirmed chemisorption between Cu(II) ions and functional groups present on MPWS including sulfhydryl groups, amine groups, hydroxyl groups, and carboxyl groups. Overall, the main mechanisms governing Cu(II) uptake onto MPWS included coordination, ion exchange, electrostatic adsorption, and physical adsorption.

Copper induces cytotoxicity in freshwater bivalve Anodonta woodiana hemocytes

Hemocytes of freshwater bivalves are an important target model for evaluating copper (Cu) toxicity in vitro, with excess Cu causing adverse responses in these organisms. Despite this, the mechanisms underlying cytotoxicity remain poorly understood. The freshwater bivalve Anodonta woodiana, employed as a model organism in freshwater environments, was utilized in this study. Hemocytes of A. woodiana were exposed to various aqueous Cu treatments (0.001, 0.01, 0.1, 1, and 10 mg/L), and a control group (no Cu added) for 3 h to investigate the cytotoxic mechanisms of Cu. The results showed a significant increase in the production of reactive oxygen species in hemocytes of all Cu exposed groups compared to the control (p < 0.05). Remarkably, Cu treatments disrupted the cellular membrane (p < 0.05) but did not induce significant changes in the stability of the lysosomal membrane. Cu targeted the mitochondria, leading to a reduction in mitochondrial membrane potential. Additionally, all Cu treatments significantly increased the degree of DNA damage (p < 0.05). Cellular damage and a significant decline in cell viability were observed when the Cu exposure concentration reached 0.1, 1, and 10 mg/L (p < 0.05). Our study provides new insights into the cytotoxicity mechanisms triggered by Cu in hemocytes of the freshwater bivalve A. woodiana, even under environmentally relevant conditions of 0.01 mg/L exposure.

Synergistic and antagonistic adsorption mechanisms of copper(II) and cefazolin onto bio-based chitosan/humic composite: A combined experimental and theoretical study

In this study, a bio-based chitosan adsorbent modified by humic was synthesized. The adsorbent exhibited amphoteric adsorption properties and had a higher adsorption capacity for Cu(II) and cefazolin (CEF) than its precursors. The impacts of pH on the speciation and adsorption of Cu(II) and CEF were analyzed. The synergistic and antagonistic adsorption in Cu(II)/CEF co-existing system were systematically investigated. The adsorption amount of CEF significantly increased by 84 %, owing to the bridge effect of Cu(II). While the uptake of Cu(II) decreased by 29 % at CEF concentration of 0.3 mmol/L, due to the formation of organic ligand complex between Cu(II) and CEF with low affinity to the adsorbent. The adsorption mechanisms of Cu(II) and CEF were analyzed by XPS and Density functional theory (DFT). Through DFT calculations, the interaction configurations of Cu(II) and CEF on adsorbent as well as Cu(II)-CEF complexes were configurated. The possible Cu(II)-CEF complexes configuration were optimized, and the complex configuration (Cu-N2/O1/O2) was the most stable combination structure with the lowest binding energy (−2066.61 kJ/mol). Interaction region indicator (IRI) model further elucidated the chemical and weak interactions between CEF and Cu(II) in coexisting system. In addition, the influence of common inorganic electrolytes on the adsorption of Cu(II) and CEF was assessed. The adsorbent could be stably recycled for five cycles with little loss, indicating the potential application in the treatment of combined pollution. This study proposed more insights into the interactions of heavy metal ions and antibiotics in the coexistence system onto the adsorbents containing amine and carboxyl groups.

Remediation effect of walnut shell biochar on Cu and Pb co-contaminated soils in different utilization types

Biochar, with its dual roles of soil remediation and carbon sequestration, is gradually demonstrating great potential for sustainability in agricultural and ecological aspects. In this study, a porous biochar derived from walnut shell wastes was prepared via a facile pyrolysis coupling with in-situ alkali etching method. An incubation study was conducted to investigate its performance in stabilizing copper (Cu) and lead (Pb) co-contaminated soils under different utilization types. The biochar effectively decreased the bioavailable Cu (8.5–91.68%) and Pb (5.03–88.54%), while increasing the pH, CEC, and SOM contents in both soils. Additionally, the results of sequential extraction confirmed that biochar promoted the transformation of the labile fraction of Cu and Pb to stable fractions. The mechanisms of Cu and Pb stabilization were found to be greatly dependent on the soil types. For tea plantation yellow soil, the main approach for stabilization was the complexation of heavy metals with abundant organic functional groups and deprotonation structure. Surface electrostatic adsorption and cation exchange contributed to the immobilization of Cu and Pb in vegetable-cultivated purple soil. This research provides valuable information for the stabilization of Cu and Pb co-contaminated soils for different utilization types using environmentally-friendly biochar.

Transpiration effect on magneto-flow of ternary hybrid nanofluid above an exponentially elongating sheet

Nanotechnological research advancements have introduced ternary hybrid nanofluids (THNFs), new technological fluids with augmented thermal properties that give better results than regular nanofluids. This work addresses THNF flow and thermal transmission features induced by an exponentially extending surface with an uneven heat source and viscid dissipation effects. The prime aim of this research is to examine the augmented energy transfer mechanism of Cu + Ag + F e 3 O 4 THNF with suction and injection situations. The transformed ordinary differential equations (ODEs) and edge limitations are exercised by employing bvp5c MATLAB package. The computational outcomes of the flow and energy fields were illustrated thru graphical and numerical trends. The energy transfer ability is developed in the suction case as equated with the injection case. The uneven heat rise factor tends to augment the rate of heat transfer and thermal fields of the THNF.

The enrichment and transformation mechanism of Pb and Cu in suspension magnetization roasting and magnetic separation from iron tailings

Magnetic iron concentrate (MIC) and nonmagnetic tailings (NT) are obtained from magnetization roasting of iron tailings (IT). MIC containing Pb adversely affects blast furnace ironmaking, while Cu in NT poses leaching risks. This study utilizes fast pyrolysis-suspension magnetization roasting to recover iron from IT. The enrichment of Pb, Cu, and the phase transformation mechanism of Cu in the process of suspension magnetization roasting and magnetic separation were clarified. Results show 96.13 % of Cu in IT is in limonite and 47.23 % of Pb is associated with iron. At 750 °C, with 10 % dosage of biomass pyrolysis and 10 min roasting, Pb, Cu and Fe contents in MIC are 0.96, 2.14 and 3.17 times that of NT. Increasing roasting temperature enhances Cu associated with iron enrichment into the MIC, while oxidation of free copper oxide associated with iron forms magnetic copper ferrite. Increased pyrolyzed biomass leads to over-reduction of magnetite associated with Cu to FeO associated with Cu, promoting magnetic copper ferrite decomposition into FeO and free copper oxide. This research holds significant importance in controlling the quality of MIC and the storage risk of IT, and provides theoretical guidance for the regulation and recovery of valuable metals in subsequent processes.

Protein-Labeling Reagents Selectively Activated by Copper(I).

Copper is an essential trace element that participates in many biological processes through its unique redox cycling between cuprous (Cu+) and cupric (Cu2+) oxidation states. To elucidate the biological functions of copper, chemical biology tools that enable selective visualization and detection of copper ions and proteins in copper-rich environments are required. Herein, we describe the design of Cu+-responsive reagents based on a conditional protein labeling strategy. Upon binding Cu+, the probes generated quinone methide via oxidative bond cleavage, which allowed covalent labeling of surrounding proteins with high Cu+ selectivity. Using gel- and imaging-based analyses, the best-performing probe successfully detected changes in the concentration of labile Cu+ in living cells. Moreover, conditional proteomics analysis suggested intramitochondrial Cu+ accumulation in cells undergoing cuproptosis. Our results highlight the power of Cu+-responsive protein labeling in providing insights into the molecular mechanisms of Cu+ metabolism and homeostasis.

Electrical sliding friction wear behaviors and mechanisms of Cu–Sn matrix composites containing MoS2/graphite

Cu–Sn matrix composites were prepared by vacuum hot press sintering technique with the addition of MoS2, graphite and a mixture of MoS2/graphite, respectively. The friction wear behaviors and contact resistance of the three composites under different currents were investigated and compared. The friction film formed on the friction surface was analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The wear mechanism and the evolution of friction film composition of the composites under different currents were revealed. The results showed that MoS2 and graphite had synergistic lubrication effects. The Cu–Sn-Graphite-MoS2 composite exhibited low wear rates and the lowest and most stable contact resistance. MoS2 could effectively promote the formation and integrity of the friction film and optimize the friction wear performance. With the increase of current, the graphite content in the friction film rose, which helped to reduce the oxidation and consumption of the friction film. The increase in current accelerated the shedding of lubricating particles and the softening of lubricating film, making the lubricating film denser and reducing the oxidation depth.