Role Of Cu Research Articles

Efficient electrocatalytic reduction of nitrate to ammonia using Cu–CeO2 solid solution

Electrocatalytic nitrate reduction reaction (EC-NITRR) is expected to replace Haber-Bosch process for green ammonia (NH3) production. Currently, many catalysts often result in low NH3 yields and low faraday efficiencies due to the lack of active sites. In this study, Cu-doped CeO2 solid solution catalyst was prepared for EC-NITRR using transition metal ions doping. The addition of Cu significantly improved the oxygen vacancy (Ov) concentration of CeO2 and provided more active sites for NO3− catalysis. Meanwhile, the internal charge transfer capability and surface catalytic kinetics of the catalyst are enhanced by the excellent redox capability of Ce3+ and Cu+. Compared with bare CeO2, the NH3 yield of 7% Cu–CeO2 increased by 1.88 times. This work provides new ideas for the design of green and efficient catalysts for EC-NITRR by identifying the role of Cu in the mechanism of doping regulation of CeO2.

The role of Cu doped Ba0.5Sr0.5Fe0.95Zr0.05O3-δ: Local structure distortion, conductivity, and magnetization

The composition Ba0.5Sr0.5Fe1-xCuxZr0.05O3-δ (BSFCZ-x, x = 0–0.20) was successfully synthesized by the sol-gel self-combustion method using citric acid as fuel combustion. Structure, local structure, electrical, and magnetic properties are investigated. The X-ray diffraction revealed the oxides exhibit a cubic structure (Pm3 m), and the lattice parameter increases with x. The X-ray absorption data are analyzed to determine the oxidation state of B site metal transition Fe and Cu through edge-energy E0 evaluation. Fe performs the oxidation states Fe3+ and Fe4+, similarly to Cu2+ and Cu3+. Furthermore, the pre-edge was analyzed to determine the spin state configuration of the 3d subshell. The local lattice distortion was evaluated through EXAFS, resulting in a distorted FeO6 octahedron elongated to the z-axis, inducing the Jahn-Teller effect. The nonstoichiometric δ-value (3-δ) measurement leads to oxygen vacancy VO⦁⦁ defect. The electrical conductivity of semiconducting behavior increases significantly after Cu is dissolved in BSFZ up to 60 S/cm at 500 °C, from initially 5 S/cm. Furthermore, the magnetic properties show a slight magnetic saturation Ms for BSFZ related to the low spin state configuration of Fe 3d subshell, then significantly increased on BSFCZ samples due to Cu provoking spin state dragged partly to high spin state configuration.

Copper homeostasis dysregulation in respiratory diseases: a review of current knowledge.

Cu is an essential micronutrient for various physiological processes in almost all human cell types. Given the critical role of Cu in a wide range of cellular processes, the local concentrations of Cu and the cellular distribution of Cu transporter proteins in the lung are essential for maintaining a steady-state internal environment. Dysfunctional Cu metabolism or regulatory pathways can lead to an imbalance in Cu homeostasis in the lungs, affecting both acute and chronic pathological processes. Recent studies have identified a new form of Cu-dependent cell death called cuproptosis, which has generated renewed interest in the role of Cu homeostasis in diseases. Cuproptosis differs from other known cell death pathways. This occurs through the direct binding of Cu ions to lipoylated components of the tricarboxylic acid cycle during mitochondrial respiration, leading to the aggregation of lipoylated proteins and the subsequent downregulation of Fe-S cluster proteins, which causes toxic stress to the proteins and ultimately leads to cell death. Here, we discuss the impact of dysregulated Cu homeostasis on the pathogenesis of various respiratory diseases, including asthma, chronic obstructive pulmonary disease, idiopathic interstitial fibrosis, and lung cancer. We also discuss the therapeutic potential of targeting Cu. This study highlights the intricate interplay between copper, cellular processes, and respiratory health. Copper, while essential, must be carefully regulated to maintain the delicate balance between necessity and toxicity in living organisms. This review highlights the need to further investigate the precise mechanisms of copper interactions with infections and immune inflammation in the context of respiratory diseases and explore the potential of therapeutic strategies for copper, cuproptosis, and other related effects.

Copper: From enigma to therapeutic target for neurological disorder.

Neurological disorders (NDs) have a negative impact on the lives of individuals. There could be two explanations for this: unclear aetiology and lack of effective therapy. However, research in the past few years has revealed the role of bio-metals dyshomeostasis in NDs. The imbalance in copper (Cu) concentration may be one of the main causative factors in NDs. In this review, we have discussed the role of Cu in NDs, especially Alzheimer's disease (AD), including the molecular mechanisms involved in Cu-associated NDs like oxidative stress, neuroinflammation, and protein misfolding. We have also summarized the recent Cu-targeting approaches and highlighted the in vitro and in vivo studies recently being reported on the subject. Based on the earlier published reports, it could be speculated that the Cu targeting strategy might be an interesting and potential therapeutic approach for NDs. Various difficulties must be overcome to develop safe and efficient Cu-targeting medications for NDs.

25 Evaluating serum copper and kidney function in a cohort of bariatric surgery patients

OBJECTIVES/GOALS: High serum copper (Cu) levels have previously been described in bariatric patients. The kidneys are a target organ for Cu toxic insult but the role of Cu on kidney function (eGFR) is uncertain. This study examines the association between Cu and eGFR in a bariatric population in Southeast Louisiana. METHODS/STUDY POPULATION: Seven hundred fifty patients will be recruited from the Bariatric Center of the University Medical Center in New Orleans. Inclusion criteria include: age ≥ 18 years, clinic visit between June 1, 2018 – May 31st 2024, and having a serum Cu test result. Covariables such as inflammatory markers and hormonal contraception use will be assessed as potential confounders. Blood pressure will be assessed as a potential effect modifier. Data will be obtained from electronic medical records. Two cohorts will be assembled, a pre-surgery cross-sectional cohort and another followed post-surgery. Separate models will be developed stratified by race-ethnicity. RESULTS/ANTICIPATED RESULTS: In a pilot study of bariatric patients 26% had elevated (>155 mcg/dl) serum Cu and pronounced racial differences were noted. Characteristics consisted of a mean BMI of approximately 50 kg/m2; 91% were female and 69% were Black. Black patients had approximately double the prevalence (OR 1.98; 95% CI: 1.15, 3.4) compared to white patients. Due to the dual nature of the kidneys’ involvement in metabolism via excretion and being the target organ for toxic insult, racial differences in exposure, coupled with the disproportionate rates of chronic kidney disease in Black adults, may be an explanation for the association between elevated Cu levels and eGFR in Black adults in this study. DISCUSSION/SIGNIFICANCE: Results from this study will provide insight into the prevalence of Cu and its association with kidney function in a bariatric population. Chronic kidney disease or other forms of renal impairment may result in the need for more conservative guidelines for dietary copper in bariatric medicine.

Cu single atoms anchored on hydrangea-like carbon nitride for facilitating photo-Fenton: Role of Cu2+/Cu+ cycle

Single-atom photo-Fenton (PF) reaction is widely employed for the degradation of antibiotics and water disinfection. However, the key fundamental issues of the valence state cycling of single-atom metals and the activation of hydrogen peroxide (H2O2) in the PF process remain indistinct. Herein, we developed a catalyst donated as Cu single atoms anchored hydrangea-like carbon nitride (Cu-SA/CNH) with Cu−N4 coordination for PF reaction. Compared to pristine CNH, the Cu-SA/CNH exhibited a 2.42-fold increase in PF kinetics. The Cu-SA/CNH/PF system achieved 98.1% degradation efficiency of tetracycline and effectively inactivated Escherichia coli within 30 min. Density functional theory calculations demonstrated that the formation of Cu−N4 effectively improved the energy of the Cu d orbitals, leading to the generation of intermediate states that facilitated the Cu2+/Cu+ cycle. The adsorption capacity of Cu dxz orbitals on H2O2 increased nearly 10 times. This work provides valuable insights for enhancing single-atom PF activity to address environmental pollution.

Cu Promoted the Dynamic Evolution of Ni-Based Catalysts for Polyethylene Terephthalate Plastic Upcycling.

Upcycling plastic wastes into value-added chemicals is a promising approach to put end-of-life plastic wastes back into their ecocycle. As one of the polyesters that is used daily, polyethylene terephthalate (PET) plastic waste is employed here as the model substrate. Herein, a nickel (Ni)-based catalyst was prepared via electrochemically depositing copper (Cu) species on Ni foam (NiCu/NF). The NiCu/NF formed Cu/CuO and Ni/NiO/Ni(OH)2 core-shell structures before electrolysis and reconstructed into NiOOH and CuOOH/Cu(OH)2 active species during the ethylene glycol (EG) oxidation. After oxidation, the Cu and Ni species evolved into more reduced species. An indirect mechanism was identified as the main EG oxidation (EGOR) mechanism. In EGOR, NiCu60s/NF catalyst exhibited an optimal Faradaic efficiency (FE, 95.8%) and yield rate (0.70 mmol cm-2 h-1) for formate production. Also, over 80% FE of formate was achieved when a commercial PET plastic powder hydrolysate was applied. Furthermore, commercial PET plastic water bottle waste was employed as a substrate for electrocatalytic upcycling, and pure terephthalic acid (TPA) was recovered only after 1 h electrolysis. Lastly, density functional theory (DFT) calculation revealed that the key role of Cu was significantly reducing the Gibbs free-energy barrier (ΔG) of EGOR's rate-determining step (RDS), promoting catalysts' dynamic evolution, and facilitating the C-C bond cleavage.

Boosting the electroreduction of CO2 to liquid products via nanostructure engineering of Cu2O catalysts

The electrochemical reduction of CO2 presents a promising pathway for storing intermittent renewable energy in the form of chemical bonds, thereby mitigating CO2 emissions and enabling the production of sustainable fuels. In this work, we demonstrate nanoscale engineering of oxygen vacancy and morphology simultaneously on Cu2O catalysts for electrochemical reduction of CO2 to liquid products (formate and ethanol). By comparing the performance of cube- and tetrakaidecahedron-like Cu2O catalysts, we have demonstrated that the flower-like Cu2O catalyst, enclosed with rich oxygen vacancy defects, exhibited superior performance in the reduction of CO2 to liquid products. Moreover, the synergetic role of Cu+ also contributed to the enhanced activity by promoting CO2 adsorption and facilitating C–C coupling. As a result, the peak Faradaic efficiency (FE) for liquid products of 95.5 % was obtained, associated with a high ethanol FE of 52.6 % and formation rate of 23.8 μmol h−1 cm−2 within a H-cell. Furthermore, within a flow cell configuration, we have observed a significant improvement in the generation of formate, maintaining FE values above 70 % even under high current densities of up to 400 mA cm−2. In-situ Raman spectroscopic measurements allow us to identify and track key intermediates involved in the CO2 reduction to formate and ethanol. This detailed understanding of the reaction pathways adds to our fundamental knowledge and provides valuable insights for the development of morphology-controlled electrocatalysts targeting efficient conversion of CO2 into liquid products.

Cu nanoparticles grafting on the surface of ZnO nanostructures to boost the porosity and surface area for effective removal of manganese ions from aqueous solutions

Designing highly adsorptive materials for wastewater treatment via facile approaches is still challenging. To boost the recovery of heavy metals from wastewater, surface and structure modification are considered a successful route. Herein, we report the design of ZnO nanoparticles by a simple thermal decomposition method followed by grafting Cu nanoparticles (Cu NPs) over the ZnO surface. Cu/ZnO was prepared with different Cu ratios, 0.01 and 1%. It was found that incorporating Cu into ZnO improved the porosity and surface area of ZnO. The adsorption ability of Cu/ZnO compared with bare ZnO was studied towards removing manganese ions from wastewater. The effects of several parameters, such as pH, temperature, contact time, and initial ion concentrations, were studied. The maximum removal of manganese was found at pH 2, 20 °C after 60 min in the presence of 1 g/L adsorbent. The role of Cu grafted on the surface of ZnO was discussed. The rates of adsorption were found to follow the pseudo-second-order model. The results showed better fitting to Freundlich isotherm. The thermodynamic study revealed that the sorption process is spontaneous, exothermic, and favorable at low temperatures. The free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) changes were calculated to predict the nature of adsorption.Graphical

Flotation separation of chalcopyrite from molybdenite with sodium thioglycolate: Mechanistic insights from experiments and MD simulations

The pivotal roles of Cu and Mo in industrial applications accentuate the importance of effectively separating and recovering chalcopyrite and molybdenite. They commonly exist together in natural environments, necessitating their segregation prior to engaging in smelting processes. The separation is mainly accomplished through flotation. The inadequate comprehension of the mechanisms of thiol depressants, commonly used in the separation of chalcopyrite and molybdenite, poses challenges to both resource recovery and the development of depressants. Based on the bulk flotation practice of copper-molybdenum sulfide minerals, this study investigated the separation effect and mechanism of sodium thioglycolate (STG) on xanthate-treated chalcopyrite and molybdenite. Flotation and contact angle tests validate that STG enhances the hydrophilicity of chalcopyrite surfaces, leading to an 83.79% flotation separation efficiency for molybdenite. Various methodologies were employed to explore the mechanism of the depressant, encompassing open-circuit potential measurements, electrochemical impedance spectroscopy, X-ray photoelectron spectroscopy, infrared and ultraviolet spectroscopy, time-of-flight secondary ion mass spectrometry, classical molecular dynamics and ab initio molecular dynamics simulations. The stable adsorption layer of STG is established by the interaction of thiol groups from STG with Cu and Fe sites on the chalcopyrite surface, resulting in the formation of Cu(I)-S and Fe(III)-S structures. The adsorption density of STG layer on the chalcopyrite surface is four times greater than that on molybdenite. Additionally, following the adsorption of STG, the previously adsorbed xanthate chalcopyrite surface is desorbed with an efficiency of 65.88%. These findings contribute to the elucidation of the mechanistic understanding of thiol-containing depressants in the flotation separation process of copper-molybdenum sulfide minerals and establish a basis for the prospective advancement of mineral processing reagents.

Converting Glycerol into Valuable Trioses by Cuδ+ -Single-Atom-Decorated WO3 under Visible Light.

Photocatalytic selective oxidation under visible light presents a promising approach for the sustainable transformation of biomass-derived wastes. However, achieving both high conversion and excellent selectivity poses a significant challenge. In this study, two valuable trioses, glyceraldehyde and dihydroxyacetone, are produced from glycerol over Cuδ+ -decorated WO3 photocatalyst in the presence of H2 O2 . The photocatalyst exhibits a remarkable five-fold increase in the conversion rate (3.81 mmol ⋅ g-1 ⋅ h-1 ) while maintaining a high selectivity towards two trioses (46.4 % to glyceraldehyde and 32.9 % to dihydroxyacetone). Through a comprehensive analysis involving X-ray photoelectron spectroscopy measurements with and without light irradiation, electron spin resonance spectroscopy, and isotopic analysis, the critical role of Cu+ species has been explored as efficient hole acceptors. These species facilitate charge transfer, promoting glycerol oxidation by photoholes, followed by coupling with OH- , which are subsequently dehydrated to yield the desired glyceraldehyde and dihydroxyacetone.

Converting Glycerol into Valuable Trioses by Cuδ+‐Single‐Atom‐Decorated WO3 under Visible Light

AbstractPhotocatalytic selective oxidation under visible light presents a promising approach for the sustainable transformation of biomass‐derived wastes. However, achieving both high conversion and excellent selectivity poses a significant challenge. In this study, two valuable trioses, glyceraldehyde and dihydroxyacetone, are produced from glycerol over Cuδ+‐decorated WO3 photocatalyst in the presence of H2O2. The photocatalyst exhibits a remarkable five‐fold increase in the conversion rate (3.81 mmol ⋅ g−1 ⋅ h−1) while maintaining a high selectivity towards two trioses (46.4 % to glyceraldehyde and 32.9 % to dihydroxyacetone). Through a comprehensive analysis involving X‐ray photoelectron spectroscopy measurements with and without light irradiation, electron spin resonance spectroscopy, and isotopic analysis, the critical role of Cu+ species has been explored as efficient hole acceptors. These species facilitate charge transfer, promoting glycerol oxidation by photoholes, followed by coupling with OH‐, which are subsequently dehydrated to yield the desired glyceraldehyde and dihydroxyacetone.

Assessment and Review of Heavy Metals Pollution in Sediments of the Mediterranean Sea

The impact of marine sediment pollution is crucial for the health of the seas, particularly in densely populated coastal areas worldwide. This study assesses the concentration and distribution of heavy metals in the marine sediments of the main regions of the Mediterranean Sea. The results underscore high concentrations of mercury (Hg), nickel (Ni), and copper (Cu), whereas chromium (Cr), zinc (Zn), cadmium (Cd), barium (Ba), and vanadium (V) exhibit moderate values. To assess the heavy metal results, sediment quality guidelines and pollution indices (Igeo and Geochemical Signal Type-GST) were employed, revealing a consistent trend of decreasing concentrations from the coastal zone to the open sea. Principal Component Analysis (PCA) emphasizes the significant roles of Cu, Zn, Ba, and Cr in sediment chemistry. The study suggests that the distribution patterns of heavy metals are linked to wastewater discharges in coastal areas, requiring effective management strategies to ensure the health of the Mediterranean Sea.

ATP7A-dependent copper sequestration contributes to termination of β-CATENIN signaling during early adipogenesis

ObjectivesAdipocyte fate determination is tightly regulated by extrinsic signaling pathways and intrinsic metabolic and morphologic changes that maintain adipose tissue function. Copper (Cu) homeostasis is required for the normal metabolism of mature adipocytes, whereas the role of Cu in adipogenesis is unclear. MethodsTo determine the role of Cu is adipocytes differentiation, we used 3T3-L1 adipocytes, immunocytochemistry, X-ray fluorescence, mass-spectrometry, pharmacological treatments, and manipulations of copper levels. ResultsIn differentiating 3T3-L1 cells, adipogenic stimuli trigger the upregulation and trafficking of the Cu transporter Atp7a, thus causing Cu redistribution from the cytosol to vesicles. Disrupting Cu homeostasis by the deletion of Atp7a results in Cu elevation and inhibition of adipogenesis. The upregulation of C/EBPβ, an initial step of adipogenesis, is not affected in Atp7a−/− cells, whereas the subsequent upregulation of PPARγ is inhibited. Comparison of changes in the Atp7a−/− and wild type cells proteomes during early adipogenesis revealed stabilization of β-catenin, a negative regulator of adipogenesis. Cu chelation, or overexpression of the Cu transporter ATP7B in Atp7a−/− cells, restored β-catenin down-regulation and intracellular targeting. ConclusionsCu buffering during early adipogenesis contributes to termination of β-catenin signaling. Abnormal upregulation of β-catenin was also observed in vivo in the livers of Atp7b−/− mice, which accumulate Cu, suggesting a tissue-independent crosstalk between Cu homeostasis and the Wnt/β-catenin pathway. These results point to a new regulatory role of Cu in adipocytes and contribute to better understanding of human disorders of Cu misbalance.

Atomistic understanding of enhanced selectivity in photocatalytic oxidation of benzyl alcohol to benzaldehyde using graphitic carbon nitride loaded with single copper atoms.

The loading of graphitic carbon nitride (gCN) with transition metals has received significant attention for efficient light-driven catalysis. However, the contribution of the loaded metals to enhanced performance remains unclear. In this study, Cu is loaded onto gCN to understand how photocatalytic activity is regulated by the loaded metals. Loading gCN with 3 wt% of Cu increases the electron population by 8.1 and 4.6 times under UV (λ < 370 nm) and visible light (390 < λ < 740 nm), respectively. This sample shows nearly 100% selectivity for oxidizing benzyl alcohol to benzaldehyde and a high yield-to-power ratio, reaching 0.35 mmol g-1 h-1 W-1. The loaded Cu species exist as single atoms with a +1-oxidation state. Each Cu+ cation is coordinated to two (at 3 wt% Cu) or four (at 6 wt% Cu) N atoms within the cavity of the gCN framework. Doubling the Cu loading results in a smaller electron population and coordinatively more saturated Cu+ cations, making it catalytically less reactive. Ab initio molecular dynamics simulations show that Cu+ cations produce filled mid-gap states above the valence band, which function as hole traps and hence oxidation centers. The Cu+ cation and the neighboring N atoms are electron-depletion and electron-accumulation sites due to Cu → N electron transfer, making it highly reactive for oxidative transformations via the hole transfer pathway. The role of Cu as a hole-transfer site updates the received understanding that surface-loaded Cu serves as an electron-accumulation site. A strong correlation is observed between the electron population at steady-state and the product yield, indicating that it could serve as a promising performance indicator for the design of future photocatalysts.

Synergetic anion-cation co-doping in Na0.44MnO2 boosting a high-stability and improved-kinetics cathode for sodium ion battery

Tunnel-type manganese-based oxide cathodes of sodium-ion batteries have attracted enormous attentions due to their advantages of low cost, good endurance to the ambient air and superior cycling stability. However, they still suffer from successive phase transitions and sluggish kinetics, which hampers their further practical applications. Herein, we introduce Cu2+ and F− into the typical tunnel material Na0.44MnO2 to improve the abovementioned shortages for the first time. As a result, the ultra-stable cycling performance (capacity retentions of 98.9% after 150 cycles at 120 mA/g and 98.0% after 200 cycles at 360 mA/g) and enhanced Na+ diffusion rate can be achieved thanks to the synergistic effect of anion-cation co-doping. More importantly, with the aid of experiments and theoretical calculations, we unequivocally shed light on the role of Cu2+ and F−, respectively. Besides, the underlying practical value of the optimal case is assessed in the full cell. This work provides a universal perspective for designing oxide cathodes with respectable performance, and paves a new way to promote the practical applications of SIBs.

Understanding the Corrosion of Copper in Nitric Acid By Tuning the Solution Chemistry

The used fuel container (UFC) is a key engineered barrier to permanently contain and isolate used nuclear fuels underground in deep geological repositories (DGR) to be implemented in Canada, Sweden and Finland.1,2 Copper is used for corrosion protection in the current design of the UFC. Within a DGR, radiolysis of humid air will result in the formation of nitric acid.3 Recent studies showed that copper corrodes faster in nitric acid when oxygen is present, which will be the case for a short period after the UFC’s emplacement.4 When the oxygen becomes depleted in a DGR, the corrosion of copper will be minimal but can be affected by corrosion products such as Cu+, Cu2+, NO2 - and NO. Previous results suggest that the presence of copper ions in the solution surrounding the copper can activate nitrate as a cathodic reagent.5 A possible mechanism is that Cu+ reacts with nitrate through its oxidation to Cu2+, which then reacts with metallic copper through its comproportionation reaction, accelerating the corrosion process.5 Yet, a precise mechanistic understanding of the role of Cu+, such as the degree to which oxidation of Cu+ occurs in solution, or if Cu+ simply acts as a catalyst for nitrate reduction or decomposition, is missing. As a result, an improved understanding of the influence of solution parameters on the corrosion mechanisms of copper in nitric acid is needed, including the presence of oxidants and Cu+-chelating species such as chloride.Herein, the interplay between the dissolved redox couples, Cu+/Cu2+ and NO3 -/NO2 - and Cl- is explored, and their effect on the corrosion of copper is studied by linear sweep voltammetry and polarization resistance and Tafel analysis. The interpretation of linear polarization resistance measurements in the presence of multivalent ions and the role of corrosion products are discussed.1 P. G. Keech, P. Vo, S. Ramamurthy, J. Chen, R. Jacklin and D. W. Shoesmith, Corrosion Engineering, Science and Technology, 49, 2014, 425-430.2 F. King, L. Ahonen, C. Taxen, U. Vuorinen and L. Werme, Copper corrosion under expected conditions in a deep geologic repository (SKB-TR--01-23), 2001. Sweden.3 R. P. Morco, J. M. Joseph, D. S. Hall, C. Medri, D. W. Shoesmith and J. C. Wren, Corrosion Engineering, Science and Technology, 52, 2017, 141-147.4 J. Turnbull, R. Szukalo, M. Behazin, D. Hall, D. Zagidulin, S. Ramamurthy, J. Wren and D. Shoesmith, Corrosion, 74, 2017, 326-336.5 J. Turnbull, R. Szukalo, D. Zagidulin, M. Biesinger and D. W. Shoesmith, Materials and Corrosion, 72, 2021, 348–360.

Histatin-5 interacts with cellular copper to promote antifungal activity against Candida albicans.

Histatin-5 (Hist-5) is an antimicrobial peptide found in human saliva that functions to defend the oral cavity from microbial infections, such as those caused by the fungal pathogen Candida albicans (C. albicans). Hist-5 can bind Cu in multiple oxidation states, Cu2+ and Cu+in vitro, and supplemental Cu2+ has been shown to improve the fungicidal activity of the peptide against C. albicans in culture. However, the exact role of Cu on the antifungal activity of Hist-5 and whether direct peptide-Cu interactions occur intracellularly has yet to be fully determined. Here, we used a combination of fluorescence spectroscopy and confocal microscopy experiments to show reversible Cu-dependent quenching of a fluorescent Hist-5 analogue, Hist-5*, indicating a direct interaction between Hist-5 and intracellular Cu. X-ray fluorescence microscopy images revealed peptide-induced changes to cellular Cu distribution and cell-associated Cu content. These data support a model in which Hist-5 can facilitate the hyperaccumulation of Cu in C. albicans and directly interact with Cu intracellularly to increase the fungicidal activity of Hist-5.

Synergy between Cu and Co in a Layered Double Hydroxide Enables Close to 100% Nitrate-to-Ammonia Selectivity.

Nitrate electroreduction (NO3RR) holds promise as an energy-efficient strategy for the removal of toxic nitrate to restore the natural nitrogen cycle and mitigate the adverse impacts caused by overfertilization from suboptimal agricultural practices. However, existing catalysts suffer from limited electrocatalytic activity, poor selectivity, inadequate durability, and low scalability. To address this quadrilemma, in this study, we developed a cost-effective layered double hydroxide (LDH) electrocatalyst with a lamellar structure that presents trimetallic CuCoAl active sites on the nanomaterial surface. This codoping design enabled electrochemical upcycling of nitrate into ammonia exclusively and efficiently with an onset potential at 0 V vs RHE, where the electrocatalytic process is less energy intensive and has a lower carbon footprint than conventional practices. The synergistic interaction among Cu, Co, and Al further afforded a 99.5% Faradic efficiency (FE) and a yield rate of 0.22 mol h-1 g-1 for nitrate-to-ammonia electroreduction, surpassing the performance of state-of-the-art nonprecious metal NO3RR electrocatalysts over an extended operation period. To gain insights into the origin of the catalytic performance observed on LDH, control materials were employed to elucidate the roles of Cu and Co. Cu was found to improve the NO3RR onset potential despite displaying limited FE for ammonia synthesis, while Co was discovered to suppress the formation of nitrite byproduct though requiring large overpotential. Simulated wastewater containing phosphate and sulfate, which are typically present in industrial effluents, was used to further investigate the effect of electrolytes on NO3RR. Intriguingly, the use of phosphate buffer resulted in a superior yield rate and FE for ammonia production while simultaneously inhibiting nitrite byproduct formation compared with the sulfate case. These experimental findings were supported by density functional theory (DFT) calculations, which explored the adsorption strength of nitrate adducts adjacent to coadsorbed electrolytes on the LDH surface. Additionally, the relative free energies of NO3RR species were also computed to examine the proton-coupled electron transfer (PCET) mechanism on CuCoAl LDH, shedding light on the potential-dependent step (PDS) and the exclusive selectivity for nitrate-to-ammonia conversion. The CuCoAl LDH developed here offers scalability by eliminating the need for precious metals, rendering this earth-abundant catalyst particularly appealing for sustainable nitrate electrovalorization technology.

Copper Coordination‐Based Nanomedicine for Tumor Theranostics

AbstractCopper (Cu) is an essential micronutrient for a variety of basic biological processes, including cell metabolism, proliferation, and angiogenesis. Recently, the concept of cuproptosis has been found to be related to the direct binding of Cu to the lipoylated components of the tricarboxylic acid cycle. This further demonstrates the important role of Cu and promotes Cu‐involved biomedical research. Currently, Cu‐related nanomedicines is mainly based on Cu coordination chemistry, and targeting Cu become a research hotspot for cancer therapy. On one hand, chelating excess Cu in vivo to inhibit angiogenesis, on the other hand, supplementing Cu and Cu‐coordinated complexes to produce oxidative stress and proteasome inhibition. In this review, the principles of Cu‐coordination chemistry and the biochemical functions of Cu ions are described, and a comprehensive review of Cu‐coordinated nanomedicine, including Cu chelation and Cu supplementation, delivery of Cu‐coordinated nanodrugs, and Cu‐coordinated nanocarriers is provided. Finally, the limitations are analyzed to point out the directions for improvement in future research. It is believed that the development of Cu‐coordinated nanomedicine will enter the fast track and show great promise in cancer theranostics.