Trace Amounts Of Cu Research Articles

Enhanced Cu-EDTA degradation with trace Cu(II) in limestone via activating PMS

Effective removal of heavy metal complexes from contaminated water remains a challenging task. In this work, a limestone/PMS system was constructed for the efficient degradation of Cu-EDTA. Under the conditions of 3.0 g/L limestone and 1.0 mM PMS, the degradation efficiency of 10.0 mg/L Cu-EDTA reached 99.0 % in 60 min, and the removal efficiency of Cu ions approached 50.0 %. The main active specie revealed by quenching and EPR experiments was the singlet oxygen (1O2). Interestingly, Trace amounts of Cu(II) in limestone react with PMS enhancing the degradation of Cu-EDTA. The results of the HPLC-MS analysis showed that the reactive species attacked the Cu–O and Cu–N bonds, as well as triggered a decarboxylation process, resulting in the decomposition of Cu-EDTA into six intermediates. Meanwhile, SEM and XPS analyses revealed that Cu ions released during the degradation of Cu-EDTA are deposited on the limestone surface as Cu(OH)2 and Cu2(OH)2CO3. In addition, the initial pH and co-existing ions have a weak effect on the system. Finally, a one-month continuous flow experiment showed that the degradation efficiency of Cu-EDTA was about 95.0 % and the removal efficiency of Cu ions was 40.0 %. In conclusion, this study provides a new approach for the destruction of metal complexes and the removal of heavy metals.

Robustly Boosting Thermoelectric Performance of N-Type PbSe via Lattice Plainification and Dynamic Doping.

Ideal thermoelectrics shall possess a high average ZT, which relies on high carrier mobility and appropriate carrier density at operating temperature. However, conventional doping usually results in a temperature-independent carrier concentration, making performance optimization over a wide temperature range be challenging. This work demonstrates the combination of lattice plainification and dynamic doping strategies is an effective route to boost the average ZT of N-type PbSe. Because Sn and Pb have similar ionic radii and electronegativity, this allows Sn to fill the intrinsic Pb vacancies and effectively improves the carrier mobility of PbSe to 1300 cm2 V-1 s-1. Furthermore, a trace amount of Cu is introduced into the Sn-filled PbSe to optimize the carrier concentration. The extra Cu is situated in the interstitial sides of the lattice, which undergoes a dissolution-precipitation process with temperature, leading to a strongly temperature-dependent carrier density in the material. This dynamic doping effectively improves the electrical transport properties and is also valid to suppress the lattice thermal conductivity. Ultimately, the resulting PbSn0.004Se+3‰Cu obtains a maximum ZT of ≈1.7 at 800 K and an average ZT of ≈1.0, with a 7.7% power generation efficiency in a single-arm device, showing significant potential for commercial application.

The influence of recycling on the localized corrosion susceptibility of extruded AA6063 alloys

An approach involving the quantification of microstructure characterized by different techniques such as SEM, EDS, and SKPFM is statistically treated to provide a deeper insight into the influence of recycling AA6063 on localized corrosion susceptibility. Particularly, the intermetallic particles and the two forms of localized corrosion – pitting and intergranular corrosion are systematically documented, measured, and analyzed. Even trace amounts of Cu and Zn introduced into the alloy from recycling had a remarkable effect on the localized corrosion susceptibility. The study found that the initiation and early evolution of the two localized corrosions are in competition, and the predominance of one over the other is closely linked to the composition of the alloy, and microstructure. Recycled variants with higher trace Cu made the alloy more susceptible to pitting attack whereas higher trace Zn is linked with greater IGC susceptibility. The trace amount of higher Zn addition has a particularly beneficial effect on pitting susceptibility as it reduces the likelihood of pitting even in alloys with a higher trace Cu content. The SKPFM results obtained in this study provided a basis for the circumferential pitting susceptibility around intermetallic particles, as a higher volta potential difference (∆V) implied a higher driving force for corrosion. ∆V differences between the different variants were further explained based on trace recycled element distribution in the microstructure.

Effect of Cu addition on the properties of Pd-based metallic glasses by experimentation and molecular dynamics simulations

The effect of trace Cu element additions on the properties of Pd-based amorphous alloys was investigated by a combination of experimental and molecular dynamics (MD) simulations. Thin ribbons of Pd40Ni40P20 and containing different proportions of Cu (1 %, 3 %, and 5 %) were prepared, analyzed by X-ray diffraction (XRD) to determine the phase structure, tested for their thermal properties by differential scanning calorimetry (DSC), and nanoindentation to test their mechanical properties. Meanwhile, the amorphization process and compression behavior of these alloys were simulated by MD simulation, and the microstructures of the alloys were resolved by using the radial distribution function (RDF) and the coordination number distribution function (PDF), and the glass transition temperatures (Tg) were deduced from the energy variations. The Voronoi polyhedral analyses showed that the addition of trace amounts of Cu altered the content of the specific clusters, which affected the macroscopic mechanical properties. Both nanoindentation experimental and simulation results confirmed that the addition of trace Cu reduces the Tg and improved the mechanical properties of the Pd40Ni40P20 alloy while maintaining the amorphous structure.

Trace Cu (II) removal from N-methylpyrrolidone with hydrogel rich in O, N and S active sites

The presence of a considerable quantity of metal ions in N-methylpyrrolidone (NMP) applied for the cleaning of electronic devices, especially chips, results in a breakdown effect, thus affecting their overall durability and performance. Here, hydrogel that rich in O, N, and S active sites was prepared, which can effectively remove trace amounts of Cu (II) from N-methylpyrrolidone. The material was synthesized through a one-pot crosslinking and ion exchange method and is named SLH. The physicochemical properties and adsorption experiments were conducted. It was found that SLH-2 exhibited outstanding Langmuir maximum adsorption capacity of 136.99 mg/g at an initial Cu (II) concentration of 200 mg/L. By utilizing SLH-2 in electronic grade adsorption experiments, concentration of trace Cu (II) decreased from 12.3 μg/L to 5.39 μg/L. Additionally, concentration of Zn, Fe, Mg, and Ni significantly reduced to less than 1 μg/L, with –NH2 and –COOH playing crucial roles in the adsorption process. The research results indicate that predominant adsorption mechanisms are surface coordination and ion exchange. The adsorption energy between active functional groups and Cu (II) was calculated using density functional theory (DFT), revealing an affinity order of –COOH > –SO3H > –NH2 > –OH. This work not only developed an adsorbent for capturing trace Cu (II), but also provided new strategies for the removal of metal ions in wet chemicals.

Achieving Tunable Selectivity and Activity of CO2 Electroreduction to CO Via Bimetallic Silver-Copper Electronic Engineering

Electrocatalytic CO2 reduction reaction (E-CO2RR) provides a sustainable way to convert greenhouse gases into value-added chemicals and small-molecule fuels[1, 2]. However, the efficient production of a single product remains a challenge. To this end, we have constructed the Ag-Cu bimetallic system as an experimental platform to investigate the process of electronic effects on the selectivity and activity of CO products in more detail. Specifically, metallic Ag is used as the matrix and different levels of Cu (Ag, Ag99Cu1, Ag96Cu4, Ag70Cu30, Ag30Cu70, Cu) are added as modifiers of the 3d orbital electron density of the system to adjust the adsorption strength of *H (key intermediates for H2 formation), *COOH and *CO (the key intermediate of CO formation) intermediates. Combining the electrochemical test results with the DFT calculations, we obtain the following trends: The addition of trace amounts of Cu (Ag99Cu1, Ag96Cu4) can greatly enhance the catalytic potential of Ag for the selective production of CO products at low potentials, achieving near 100% selectivity for CO products (Ag96Cu4, -1V vs. RHE).The observed rate determining step of the reaction on Ag30Cu70 from CO2–*COOH to *COOH–*CO implies that adding too much Cu or leading to strong adsorption of *CO results in poisoning.It was observed that Ag96Cu4 had the optimum CO selectivity and Ag70Cu30 had the optimum CO activity current, which is different from previous concentrations on the same catalyst. (Figure 1a, b) We attribute the above findings to Ag96Cu4 effectively reducing the free energy of the formation of *COOH while maintaining a relatively high theoretical overpotential for hydrogen evolution reaction (HER), thus achieving the best CO selectivity (Figure 1c, d). While the Ag70Cu30 together activates the CO2RR and HER processes and shows relatively low formation energies of *COOH and *H, the compromised thermodynamic barrier and product selectivity allows for the best CO partial current density to be exhibited (Figure 1c, d). We believe that the electron effect will serve as an effective platform for screening selective and active catalysts. Figure1. a) FECO and b) jCO as a function of the proportion of Cu in AgxCu100-x series catalysts. c, d) The calculated free energy diagrams of CO2RR to CO and HER on fcc Ag (111), Ag96Cu4 (111), Ag70Cu30 (111), Ag30Cu70 (111) and Cu (111) surfaces at 0 V vs. RHE, respectively. Reference Grätzel, M., Nature 2001, 414 (6861), 338-344. DOI 10.1038/35104607.Zheng, Y.; Vasileff, A.; Zhou, X.; Jiao, Y.; Jaroniec, M.; Qiao, S.-Z., Journal of the American Chemical Society 2019, 141 (19), 7646-7659. DOI 10.1021/jacs.9b02124. Figure 1

CsPbX3 (X = Cl/Br, Br, Br/I, I) quantum dots and copper ions co-doped boro-germanate glasses for long wavelength pass filters

We have investigated CsPbX3 (X = Cl/Br, Br, Br/I, I) quantum dots (QDs) co-doped with various metal ions in boro-germanate glass matrix for long wavelength pass filters. Transmittance, optical density (OD), photoluminescence (PL), PL excitation and PL decay have been evaluated. The working wavelength of filters has been extended to wide range from blue 475 nm to dark red 680 nm. Among these metal ions, only Cu2+ ions have obvious quenching or enhancement effect on the PL intensity and lifetime. Small amount Cu2+ of 0.005–0.3 mol% is used for PL quenching and maintaining excellent transmittance and optical density. Trace amounts of Cu2+ ions (≤0.01 mol.%) have obvious effect. The ratios of I0/I and τ0/τ are used to evaluate the quenching type and mechanism. The quenching/enhancement effect is different for different CsPbX3 (X = Cl/Br, Br, Br/I, I) QDs glasses (QDGs), showing strong correlation with the anionic composition (i.e. the bandgap) of CsPbX3 QDs. As Cu2+ concentration increases, the PL intensity is quenched for CsPb(Cl/Br)3 (Cl/Br=4:1, 2:1, 1:1), CsPbBr3 and CsPb(Br/I)3 (Br/I=1:1, 1:2, 1:4) QDGs, whereas it is enhanced for CsPbI3 QDG. The PL lifetime is decreased for CsPb(Cl/Br)3 (Cl/Br=4:1, 2:1, 1:1), CsPbBr3 and CsPb(Br/I)3 (Br/I=1:1) QDGs, whereas it is increased for CsPb(Br/I)3 (Br/I=1:2, 1:4) and CsPbI3 QDGs. An energy-dependent electron transfer (ET) mechanism is proposed to explain the quenching/enhancement. The ET and backward ET result in the quenching/enhancement in PL intensity and lifetime. The optical density (OD), absorption edge, transmittance, and transition wavelength have been evaluated for filter performance. The fabricated CsPbX3 (X = Cl/Br, Br, Br/I, I) QDGs can largely meet requirements for the long wavelength pass filters.

Magnetite geochemistry and mineralogy of iron skarn in the southern Wag Water Belt, Jamaica: Implications for ore genesis

The Mavis Bank iron skarn mineralisation is located within a Paleocene to Eocene rift system typified by terrestrial and marine deposits, and extensive lava flows and subvolcanic intrusions of adakitic composition. Iron occurs primarily as massive, lenticular magnetite bodies at the contact between the intrusions and calcic Fe skarn (metasomatised limestone) which grades into a low-grade marble with disseminated magnetite. Magnetite is also disseminated in shales and lavas located within the main mineralised zones. Skarn mineralogy is poorly developed in both the endoskarn and the exoskarn with only minor occurrence of diopside. Retrograde and alteration minerals, such as epidote, chlorite, and hematite, are more common. Sulphides are rare, highly altered, and dominated by pyrite, pyrrhotite, and minor chalcopyrite. Petrographic analysis, including micro-XRF-EDS mapping of polished thin sections, shows that massive magnetite and calcic Fe skarns have minor disseminated Ti and S phases along with trace amounts of Cu and Co. Scanning electron microscope-backscattered electron (SEM-BSE) imaging of the exoskarn highlights the extent of retrograde alteration and later supergene weathering, and the presence of dissolution and reprecipitation features.The in situ trace element composition of magnetite in massive magnetite and calcic Fe skarn was determined using LA-ICP-MS. The results, when plotted on multi-element and discriminant diagrams, including Ni/(Cr + Mn) vs Ti + V, Ca + Al + Mn vs Ti + V, Ti vs V, and Ti vs Ni/Cr, are generally consistent with the geochemical signatures of skarn deposits worldwide. The mineralogy and trace element signatures suggest that the skarn deposit was formed at relatively shallow levels by low temperature hydrothermal fluids with high fO2 and fS. In addition, δ18O values of 6.6 and 7.1 ‰ obtained from massive magnetite are typical of infiltrative skarns and are consistent with a mixture of magmatic and meteoric water, and limestone oxygen isotope signatures.

Anti-Migratory and Cytotoxic Activities of [Ga(8-hydroxyquinolinato)3 ]: Roles of Endogenous Cu(II) and Drug-Induced Phenotypic Changes.

As shown by IncuCyte Zoom imaging proliferation assays, invasive triple-negative human breast MDA-MB-231 cancer cells treated with sub-toxic doses (5.0-20 μM, 72 h) of [GaQ3 ] (Q=8-hydroxyquinolinato) caused profound morphological changes and inhibition of cell migration, which were likely due to terminal cell differentiation or similar phenotypical change. This is the first demonstration of potential use of a metal complex in differentiation anti-cancer therapy. Additionally, a trace amount of Cu(II) (0.20 μM) added to the medium dramatically increased [GaQ3 ] cytotoxicity (IC50 ~2 μM, 72 h) due to its partial dissociation and the action of the HQ ligand as a Cu(II) ionophore, as shown with electrospray mass spectrometry and fluorescence spectroscopy assays in the medium. Hence, cytotoxicity of [GaQ3 ] is strongly linked to ligand binding of essential metal ions in the medium, for example, Cu(II). Appropriate delivery mechanisms of such complexes and their ligands could enable a powerful new triple therapeutic approach for cancer chemotherapy, including cytotoxicity against primary tumour, arrest of metastases, and activation of innate and adaptive immune responses.

Inhibition of photosensitized degradation of organic contaminants by copper under conditions typical of estuarine and coastal waters

Dissolved organic matter (DOM) driven-photochemical processes play an important role in the redox cycling of trace metals and attenuation of organic contaminants in estuarine and coastal ecosystems. In this study, we evaluate the effect of Cu on 4-carboxybenzophenone (CBBP) and Suwannee River natural organic matter (SRNOM)-photosensitized degradation of seven target contaminants (TCs) including phenols and amines under pH conditions and salt concentrations typical of those encountered in estuarine and coastal waters. Our results show that trace amounts of Cu(II) (25 −500 nM) induce strong inhibition of the photosensitized degradation of all TCs in solutions containing CBBP. The influence of TCs on the photo-formation of Cu(I) and the decrease in the lifetime of transformation intermediates of contaminants (TC•+/ TC•(-H)) in the presence of Cu(I) indicated that the inhibition effect of Cu was mainly due to the reduction of TC•+/ TC•(-H) by the photo-produced Cu(I). The inhibitory effect of Cu on the photodegradation of TCs decreased with the increase in Cl− concentration since less reactive Cu(I)−Cl complexes dominate at high Cl− concentrations. The impact of Cu on the SRNOM-sensitized degradation of TCs is less pronounced compared to that observed in CBBP solution since the redox active moieties present in SRNOM competes with Cu(I) to reduce TC•+/ TC•(-H). A detailed mathematical model is developed to describe the photodegradation of contaminants and Cu redox transformations in irradiated SRNOM and CBBP solutions.

Enhancing the erosion–corrosion resistance of cupronickel alloy through grain boundary engineering

The grain boundary engineering (GBE) effect on the erosion–corrosion resistance of 90/10 cupronickel alloys was studied using a self-made erosion–corrosion device. A 90/10 cupronickel alloy with abundant low-Σ coincidence site lattice grain boundaries and random grain boundary disconnectivity was fabricated through GBE. The average corrosion rate of the self-prepared alloy was reduced by 34 % to 0.0414 mm/a after the erosion–corrosion test. The corrosion product films of both samples included Cu, Cu2O, Ni(OH)2, NiO, FeO, FeOOH, and trace amounts of Cu2(OH)3Cl. A schematic diagram of the intergranular corrosion mechanism during the erosion–corrosion test was prepared.

Improving copper(II) ion detection and adsorption from wastewater by the ligand-functionalized composite adsorbent

The functional organic ligand of 4-tert-Octyl-4-((phenyl)diazenyl)phenol (TPDP) was immobilized directly onto the mesoporous silica for the fabrication of composite adsorbent to detect and remove the toxic copper (Cu(II)) ions from contaminated water. The mesoporous silica and the composite adsorbent were characterized systematically using different instrumentations. Upon addition of a trace amount of Cu(II) with composite adsorbent, a significant color was formed to visualize the Cu(II) ion detection at optimum experimental protocol. The pH played a key factor in the detection and removal operation and the optimum pH was 4.0 for this study. The effect of pH, color optimization, contact time, competing ions, and concentration was assessed systematically both in the detection and removal operations. The limit detection by the composite adsorbent to Cu(II) ion was 0.28 µg/L. The diverse metal ions did not interfere during the Cu(II) ion detection and removal by the composite adsorbent and complied with the high sensitivity for onsite uses as potential materials. The proposed adsorbent also exhibited high adsorption capacity and was well-fitted in the Langmuir adsorption isotherms in monolayer coverage and the maximum adsorption capacity was as high as 184.73 mg/g. The Cu(II) ion was eluted from the composite adsorbent using 0.15 M HCl and then simultaneously regenerated into the initial stage without losing its major functionality for the next use operation. However, the adsorption efficiency was slightly decreased after several cycles of use according to the data. Then it is estimated that the fabricated ligand-based composite adsorbent in the real waste sample treatment for detection and removal of Cu(II) ions as a low-cost material without using highly sophisticated instrumentations.

Spin-Enhanced C–C Coupling in CO 2 Electroreduction with Oxide-Derived Copper

Spin-Enhanced C–C Coupling in CO ₂ Electroreduction with Oxide-Derived Copper

A regulation strategy using trace copper boosting electrocatalytic activity of bifunctional metallic dihydroxy in hydrogen evolution and methanol oxidation

Discovering efficient and promising bifunctional electrocatalysts is pivotal for a sustainable energy system. Herein, we propose a simple and efficiency strategy to construct a highly efficient flower-like NiCo dihydroxy catalyst containing trace amounts of Cu2+. Due to the incorporation of Cu2+, low-valence Niδ+ (0 < δ < 2) and more high-valence Co3+ are formed. This indicates that part of the Co electrons are transferred to the surrounding Ni, thereby achieving electron enrichment of Ni sites and improving HER activity. The Ni2Co1Cu LDH/NF 0.008 only needs overpotentials of 19 mV and 113 mV to reach 10 mA cm−2 and 50 mA cm−2 for HER and has long-term stability, and at 1.35 V to reach 10 mA cm−2 for MOR. The catalyst can reach a cell voltage of 1.47 V for MOR and HER bifunctional catalysis. This work provides a novel strategy to fabric highly efficient dual-functional electrocatalysts of transition metal hydroxides.

Detachable all-carbon-linked 3D covalent organic framework films for semiconductor/COF heterojunctions by continuous flow synthesis

Detachable all-carbon-linked 3D covalent organic framework films for semiconductor/COF heterojunctions by continuous flow synthesis

Organic ligand interaction with copper(II) ions in both aqueous and non-aqueous media: Overcoming solubility issues for sensing

A new bis(thienyl)imidazole-based fluorescent organic molecular sensor (TIBIT) was prepared and fully characterized by NMR spectroscopy, mass spectrometry and single crystal X-ray diffraction. The sensing application of TIBIT towards metal ions in solution was investigated using UV–vis, fluorescence, and surface-enhanced Raman spectroscopy (SERS). In the organic solvent THF, TIBIT showed excellent sensitivity towards Cu(II) with a detection limit of 10 pM, whereas in aqueous media, aggregation-caused quenching (ACQ) was observed. Using a SERS substrate consisting of Au-deposited long-range ordered crystals (Au-LROCs) of polystyrene colloids and a uniform deposition of a TIBIT monolayer via bonding through the sulfur atoms of the thiophene rings, ACQ was overcome enabling the detection of trace amounts of Cu(II) in aqueous media. Using this novel approach, a detection limit of 13 nM was found, considerably lower than the recommended safe level of 20 µM regulated by the United States Environmental Protection Agency for Cu2+ in drinking water, thus demonstrating the potential of TIBIT for monitoring Cu(II) levels in water samples.

In Vitro Study of the Recruitment and Expansion of Mesenchymal Stem Cells at the Interface of a Cu-Doped PCL-Bioglass Scaffold.

Developing new barrier membranes with improved biomechanical characteristics has acquired much interest owing to their crucial role in the field of periodontal tissue regeneration. In this regard, we enriched the electrospun polycaprolactone (PCL)/gelatin (Gel) membranes by adding bioglass (BG) or Cu-doped bioglass (CuBG) and examined their cellular adhesion and proliferation potential in the presence of alveolar bone marrow-derived mesenchymal stem cells (aBMSCs). The membranes were fabricated and characterized using mechanical strength, SEM, FTIR, EDX, and ICP assay. Besides, aBMSCs were isolated, characterized, and seeded with a density of 35,000 cells in each experimental group. Next, the cellular morphology, cell adhesion capacity, proliferation rate, and membrane antibacterial activity were assessed. The results displayed a significant improvement in the wettability, pore size, and Young’s modulus of the PCL membrane following the incorporation of gelatin and CuBG particles. Moreover, all scaffolds exhibited reasonable biocompatibility and bioactivity in physiological conditions. Although the PCL/Gel/CuBG membrane revealed the lowest primary cell attachment, cells were grown properly and reached the confluent state after seven days. In conclusion, we found a reasonable level of attachment and proliferation of aBMSCs on all modified membranes. Meanwhile, a trace amount of Cu provided superiority for PCL/Gel/CuBG in periodontal tissue regeneration.

In-line detection of Cu+-related species in aged Cu plating bath using flow cell-based electrochemical method

• Method to analyze the concentrations of Cu + -related species in Cu plating bath is suggested. • The concentrations of Cu + -related species in a bath aged under open-circuit condition are evaluated. • The Cu + ion in the bath is stabilized by forming a complex with organic additives. Cu + -related species formed under electrolytic and open circuit conditions (e.g., Cu + and Cu + -3-mercapto-1-propane sulfonate (MPS)) are important intermediates that influence the performance of Cu-plating baths. However, trace amounts of Cu + -related species in the aged bath are difficult to analyze, thus making it increasingly difficult to ensure the performance of the bath. Here, an in-line and simple electrochemical method—based on a diffusion-limited current analysis of a 2-channel flow cell—was proposed to detect Cu + -related species in a bulk solution. Based on the voltammogram, in the range of 0.5–1.0 V, the aged bath possesses anodic currents related to the oxidation of Cu + -related complexes. The aged bath containing PEG revealed a single diffusion-limited current plateau at 0.5–1.0 V due to the oxidation of Cu + . In the presence of bis (3-sulfopropyl) disulfide, three current plateaus were observed, corresponding to the three-electron oxidation of the Cu(I)MPS complex. The concentrations of Cu + and Cu(I)MPS in the aged bath were evaluated using master calibration curves that were prepared based on simulation and experiment. The proposed method could be effectively utilized for the automated in-line monitoring of Cu electroplating baths.

Cu(II) assisted peroxymonosulfate oxidation of sulfonamide antibiotics: The involvement of Cu(III)

Cu(II) is generally considered to be a poor activator for PMS decomposition, thus the potential impact of trace Cu(II) on PMS induced oxidation of typical pollutants is always overlooked. In this study, we reported that trace Cu(II) could significantly promote PMS induced degradation of four selected sulfonamide antibiotics (SAs), namely, sulfamehoxazole (SMX), sulfathiazole (STZ), sulfamerazine (SMZ), and sulfamonomethoxine (SMM). Different from conventional PMS-induced oxidation process, high-valent Cu(III) was ascertained as the primary reactive intermediate for SAs degradation, which was confirmed by raman tests and electron paramagnetic resonance (EPR). High concentrations of Cu(II) or PMS were beneficial to degradation of the selected contaminants. In PMS/Cu(II) oxidation system, all the selected SAs could undergo several different degradation pathways including continuous oxidation of aniline group, hydroxylation and S–N bond cleavage. In particular, for six-membered SAs, such as SMZ and SMM, a SO2 extrusion pathway was also detected. The potential mechanism for Cu(III) formation was also proposed, which was believed to be highly related to the nature of the SAs. Hydroxylamine-SAs (N4–OH–SAs), generated from direct PMS oxidation of SAs, was deduced as the “promoter” for the whole oxidation process. And the generation of Cu(III) was likely to proceed through the interaction between PMS and Cu(I), which possibly derived from the reduction of Cu(II) by N4–OH–SAs. The results obtained in this study validated the contribution of Cu(III) to the elimination of pollutants and expanded our understanding of the oxidation process of PMS in the presence of trace amounts of Cu(II).

Effects of Cu on the corrosion behavior and microstructure of Mg–Zn–Ca bulk metallic glass

AbstractFor the purpose of developing biodegradable magnesium alloys with suitable properties for biomedical applications, Mg–Zn–Ca–Cu metallic glasses were prepared by copper mold injection methods. In the present work, the effect of Cu doping on mechanical properties, corrosion behavior, and glass‐forming ability of Mg66Zn30Ca4 alloy was studied. The experimental findings demonstrated that the incorporation of Cu decreases the corrosion resistance of alloys, but increases the microhardness and degradation rate slightly. However, the addition of a trace amount of Cu can make the samples have antibacterial properties. Therefore, Mg–Zn–Ca–Cu has great advantages in clinical implantation and is the potential implant material.