Copper Selenide Research Articles

Decellularized periosteum and sodium alginate-based photoresponsive dressing with copper selenide nanoparticles for infected-wound healing in diabetic mice

Diabetes-related skin ulcers are of significant clinical concern. Although conventional dressings have been developed, their outcomes have not been adequate, indicating the need to investigate functional dressings for the treatment of diabetic ulcers. Copper selenide nanoparticles (Cu2Se NPs) demonstrate outstanding photoresponsiveness, which is critical to the healing process. However, their limited solubility in water restricts their application. To synthesize the ODT-PMMA@Cu2Se NP-doped decellularized periosteum‑sodium alginate functional dressing-ODT-PMMA@Cu2Se/ECM-S (OP@Cu2Se/ECM-S), Cu2Se NPs were modified by n-octadecanethiol (ODT) end-functionalized poly (methacrylic acid) (PMAA) ligands homogeneously dispersed in a decellularized periosteum/sodium alginate matrix. This process improved the water solubility and stability. Moreover, under near-infrared irradiation (NIR), ODT-PMMA@Cu2Se demonstrated robust photo-responsiveness along with photothermal and photodynamic effects, leading to rapid heating and stimulation of reactive oxygen species (ROS) generation. These two processes work in concert to exhibit excellent antibacterial ability; at 20 μg/mL concentration of Cu2Se NPs, the bacterial activities of S. aureus and E. coli were 5.40 % and 0.96 %, respectively. Without the NIR laser irradiation, OP@Cu2Se/ECM-S rapidly increased the vascular endothelial growth factor (VEGF) expression, triggered the phosphatidylinositide 3-kinases (PI3K) and protein kinase B (AKT) signaling pathway, affected the expression of bFGF and CD31, and promoted neovascularization, proliferation, and cell migration. In a diabetic mouse wound model, OP@Cu2Se/ECM-S exhibited good biocompatibility and promoted epidermal regeneration, collagen deposition, and neovascularization. In a mouse model of subcutaneous abscesses, OP@Cu2Se/ECM-S also showed excellent antibacterial activity, in vivo experiments confirmed a decrease in bacterial activity to 1.97 %. Thus, OP@Cu2Se/ECM-S is a potentially useful approach for healing diabetic wounds.

Superior room temperature ammonia gas sensing of copper selenide nanoflowers

Facile wet chemical synthesis was utilized to synthesize nanoflowers of copper selenide (CuSe) that exhibited exceptional room temperature ammonia (NH3) gas sensing capability. Observations of surface morphology revealed the presence of petal-like structures arranged in a flower-like pattern. The layered materials have been analyzed for their crystalline structure, phase, composition, and band gap by utilizing X-ray diffraction, Transmission Electron Microscopy, Raman spectroscopy, and energy-dispersive X-ray spectroscopy, UV-Vis, respectively. At ambient conditions, CuSe nanoflowers-based sensor demonstrated exceptional sensitivity, reaching up to 79% (200 ppm NH3) with short response and recovery time of 12.9 s and 6.3 s, respectively, at 5 ppm gas concentration. The sensor exhibited rapid response and recovery times, a broad concentration range, long-term stability over extended periods, exceptional specificity towards NH3, and good repeatability owing to its distinct flower-shaped structures assembled in thin layers. Density Functional Theory simulations were conducted to investigate the interactions between NH3 and CuSe. Our findings revealed an increase in the adsorption energy of NH3 on CuSe, indicating a stronger binding affinity. We observed a higher charge transfer from CuSe to NH3, which suggests an increase in conductivity. This increase in conductivity enhances the superior sensing capability observed in the experimental results.

Exploring secondary optical transitions: a study utilizing the DITM method, and enhanced photocatalytic properties in Ni-doped CuSe

This study explores the simultaneous presence of two metal ions of Nickel (Ni) and Copper (Cu) on the formation of a metal selenide (Ni-doped CuSe) in an alkaline environment. The impact of Ni ions on creating the second optical transitions is investigated. Different concentrations amounts of Ni ions (0.01, 0.02, and 0.03 mol) are utilized to produce Ni-doped CuSe semiconductor thin films through a chemical solution deposition method with deposition times varying from 3 to 6 h. Absorbance spectra are employed to determine the band-gap, while Field Emission Scanning Electron Microscopy is utilized for morphological analysis. Structural and elemental analyses are conducted using X-ray Diffraction and Energy Dispersive X-ray Spectroscopy techniques. Additionally, a relatively innovative approach for determining the optical transitions, termed the Derivation Ineffective Thickness Method (DITM), is employed. DITM eliminates the need for thin film thickness and assumptions about the type of transition (direct or indirect) for band-gap calculation. Moreover, a comparison is made between the band-gap obtained from the Tauc model and the transitions obtained by DITM method. Furthermore, it is demonstrated that the optical transitions exhibit two distinct band-gaps associated with nickel selenide (NiSe) as second transition and copper selenide (CuSe) as fundamental transition. The presence of Ni is also found to enhance crystal quality. The study also briefly explores the improved photocatalytic properties of CuSe in the presence of Ni.

Copper selenide nanosheets with photothermal therapy-related properties and multienzyme activity for highly effective eradication of drug resistance

Bacterial infections are among the most significant causes of death in humans. Chronic misuse or uncontrolled use of antibiotics promotes the emergence of multidrug-resistant superbugs that threaten public health through the food chain and cause environmental pollution. Based on the above considerations, copper selenide nanosheets (CuSe NSs) with photothermal therapy (PTT)- and photodynamic therapy (PDT)-related properties have been fabricated. These CuSe NSs possess enhanced PDT-related properties and can convert O2 into highly toxic reactive oxygen species (ROS), which can cause significant oxidative stress and damage to bacteria. In addition, CuSe NSs can efficiently consume glutathione (GSH) at bacterial infection sites, thus further enhancing their sterilization efficacy. In vitro antibacterial experiments with near-infrared (NIR) irradiation have shown that CuSe NSs have excellent photothermal bactericidal properties. These experiments also showed that CuSe NSs exerted excellent bactericidal effects on wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) and significantly promoted the healing of infected wounds. Because of their superior biological safety, CuSe NSs are novel copper-based antimicrobial agents that are expected to enter clinical trials, serving as a modern approach to the major problem of treating bacterially infected wounds.

Electrostatically directed assembly of macroporous skeleton structured copper selenide for elemental mercury sequestration from coal-fired flue gas

Decontamination of Hg0 from coal-fired flue gas remains an enormous challenge. It is an imperative pursuit to design adsorbents bearing an abundance of accessible chelating sites with a high affinity toward mercury, thus achieving both rapid uptake and high capacity for Hg0. Herein, an electrostatically directed assembly strategy was designed to construct Cu2Se decorated commercial polyurethane sponge (Cu2Se/PUS) as an efficient Hg0 trap. The surface coverage of Cu2Se on the Cu2Se/PUS can be rationally adjusted by turning the charge density of Cu2Se and PUS. The saturated Hg0 adsorption capacity of Cu2Se/PUS was achieved at 217.04 mg g−1 (normalized to the Cu2Se coating amount), which was much higher than that of powdery Cu2Se (43.66 mg g−1). Multiform selenium active sites (Se- and Se2-) and copper-terminated active centers of Cu2Se/PUS co-participated in Hg0 adsorption, instead of the individual role of Se- over powdery Cu2Se. The macroporous skeleton structure and the highly dispersed Cu2Se boosted the diffusion of mercury to the active sites for immobilization, thus accelerating the consumption of multiple active sites on the Cu2Se/PUS. This work not only provided an efficient Hg0 trap but also showed great inspiration for the potential of electrostatically directed assembly methods in constructing adsorbents for diverse environmental remediations.

Highly stabilized and efficient thermoelectric copper selenide.

The liquid-like feature of thermoelectric superionic conductors is a double-edged sword: the long-range migration of ions hinders the phonon transport, but their directional segregation greatly impairs the service stability. We report the synergetic enhancement in figure of merit (ZT) and stability in Cu1.99Se-based superionic conductors enabled by ion confinement effects. Guided by density functional theory and nudged elastic band simulations, we elevated the activation energy to restrict ion migrations through a cation-anion co-doping strategy. We reduced the carrier concentration without sacrificing the low thermal conductivity, obtaining a ZT of ∼3.0 at 1,050 K. Notably, the fabricated device module maintained a high conversion efficiency of up to ∼13.4% for a temperature difference of 518 K without obvious degradation after 120 cycles. Our work could be generalized to develop electrically and thermally robust functional materials with ionic migration characteristics.

Chemical-Vapor-Deposition-Synthesized Two-Dimensional Non-Stoichiometric Copper Selenide (β-Cu2-xSe) for Ultra-Fast Tetracycline Hydrochloride Degradation under Solar Light.

The high concentration of antibiotics in aquatic environments is a serious environmental issue. In response, researchers have explored photocatalytic degradation as a potential solution. Through chemical vapor deposition (CVD), we synthesized copper selenide (β-Cu2-xSe) and found it an effective catalyst for degrading tetracycline hydrochloride (TC-HCl). The catalyst demonstrated an impressive degradation efficiency of approximately 98% and a reaction rate constant of 3.14 × 10-2 min-1. Its layered structure, which exposes reactive sites, contributes to excellent stability, interfacial charge transfer efficiency, and visible light absorption capacity. Our investigations confirmed that the principal active species produced by the catalyst comprises O2- radicals, which we verified through trapping experiments and electron paramagnetic resonance (EPR). We also verified the TC-HCl degradation mechanism using high-performance liquid chromatography-mass spectrometry (LC-MS). Our results provide valuable insights into developing the β-Cu2-xSe catalyst using CVD and its potential applications in environmental remediation.

Nanostructured Copper Selenide Coatings for Antifouling Applications.

The accumulation of microorganisms, plants, algae, or small animals on wet surfaces that have a mechanical function causes biofouling, which can result in structural or other functional deficiencies. The maritime shipping industry must constantly manage biofouling to optimize operational performance, which is a common and long-lasting problem. It can occur on any metal structure in contact with or submerged in ocean water, which represents additional costs in terms of repairs and maintenance. This study is focused on the production of antifouling coatings, made with nanoparticles of copper selenide (CuSe NPs) modified with gum arabic, within a water-base acrylic polymeric matrix. During the curing of the acrylic resin, the CuSe NPs remain embedded in the resin, but this does not prevent the release of ions. The coatings released copper and selenium ions for up to 80 days, and selenium was the element that was released the most. The adhesion of film coatings to metallic substrates showed good adhesion, scale 5B (ASTM D3359 standard). Antimicrobial activity tests show that the coatings have an inhibitory effect on Escherichia coli and Candida albicans. The effect is more noticeable when the coating is detached from the substrate and placed on a growing medium, compared to the coating on a substrate. Scanning electron microscopy (SEM) observations show that nanostructured CuSe coatings are made up of rod-shaped and spherical particles with an average particle size of 101.6 nm and 50 nm, respectively. The energy dispersive X-ray spectroscopy (EDS) studies showed that the ratio of selenium nanoparticles is greater than that of copper and that their distribution is homogeneous.

Chemical bond engineering toward extraordinary power factor and service stability in thermoelectric copper selenide

Chemical bond engineering toward extraordinary power factor and service stability in thermoelectric copper selenide

Heterodimensional hybrids assembled with multiple-dimensional copper selenide hollow microspheres and graphene oxide nanosheets for electromagnetic energy conversion and electrochemical energy storage

Heterodimensional hybrids assembled with multiple-dimensional copper selenide hollow microspheres and graphene oxide nanosheets for electromagnetic energy conversion and electrochemical energy storage

High-performance thermoelectric properties of Cu2Se fabricated via cold sintering process

The concept of a ‘phonon-liquid electron-crystal’ has received significant interest in recent years, with copper selenide (Cu2Se) emerging as one of the high-performance thermoelectric materials within this framework. This study focuses on the fabrication of Cu2Se bulk pellets through a low-temperature sintering method known as cold sintering process (CSP). The introduction of a liquid phase (thiol-amine solution) in this process facilitates the dissolution and precipitation of ion/atom clusters, resulting in sample densification. Remarkably, a sample density of nearly 90 % is achieved at a low sintering temperature of only 473 K. Furthermore, this CSP approach preserves the morphology of the Cu2Se precursor powders and effectively inhibits grain growth. Consequently, the lattice thermal conductivity of the CSP samples is significantly reduced, attributed to enhanced grain boundary phonon scattering. This leads to a substantial improvement in the figure-of-merit (ZT), increasing from 0.65 at 800 K in the hot-pressed sample to 2.13 at 800 K in the CSP sample. The advantages of CSP can be extended beyond Cu2Se, as it holds promise for enhancing the performance of various high-performance thermoelectric materials.

Evaluation of substrate temperature role on the structural, morphological, optical, and mechanical properties of magnetron sputtered Cu2Se thin films

Copper Selenide (Cu2Se) thin films were deposited on a float glass substrate using magnetron sputtering with a radio frequency (RF) source at a power of 70 W and by varying substrate temperatures (Tsub) from 50 °C to 400 °C with an interval of 50 °C. The influence of the Tsub on the morphological, structural, and mechanical characteristics of Cu2Se thin films was investigated using the Grazing Incidence X-ray diffraction (GIXRD), Raman spectra, Field Emission Scanning Electron Microscopy (FESEM) combined with energy-dispersive spectroscopy (EDS) and Nanoindentation. The results of the GIXRD analysis suggest that the cubic Cu2-xSe phase could be observed when the deposition took place at Tsub of 50 to 200 °C. However, for the films that were deposited at temperatures higher than this range, i.e., from 250 °C to 400 °C, the elements Cu and Se formed an intermediate phase. Raman bands assigned at 261 cm−1 confirm the cubic-Cu2Se phase. The average grain size measured from FESEM images increase with varying Tsub from 50 °C to 400 °C with a value of 230 nm to 320 nm. The variation in the Tsub results in the evolution of the microstructure and EDS shows the variation in the stoichiometric ratio of deposition. The energy of the band gap decreases with an increase in Tsub, leading to the overlapping of energy levels. The nanoindentation tests show that the hardness dropped as the Tsub increased from 50 °C to 400 °C. The Cu2Se film deposited at Tsub 50 °C had the highest hardness value of 1.91 ± 0.47 GPa.

Investigating the Effect of Ph Variation on the Optoelectronic and Structural Properties of Electrodeposited Copper Selenide Thin Films.

Copper Selenide (CuSe) thin film compound semiconductors have been deposited onto fluorine doped tin oxide (FTO) conducting substrates using electrodeposition technique through various electrolytic bath pH values of 2.00, 2.20, and 2.40. The deposition was carried out in potentiostatic mode using a 2-electrode system set-up at room temperature for 15 minutes at the cathodic voltage of 500 mV. The electrical and the optical properties of the thin films were carried out using photoelectrochemical (PEC) cells and ultraviolet visible spectrophotometer respectively. CuSe thin film possesses a p-type electrical conductivity and the sample grown at semiconductor and a pH of 2.2 was recorded to have the highest PEC signal and highest photo and dark currents that brings forth its maximum power. The energy band gap values of the electrodeposited CuSe thin films were observed to be 2.30 eV, 2.20 eV, and 2.00 eV at bath pH values of 2.0, 2.2, and 2.4 respectively. The optical band obtained at the various pH decreases as pH increases and these band gap values agree with the bulk band gap of CuSe. The preferred orientation peak of electrodeposited CuSe layers exists as klockmannite (CuSe) and the highest peak intensity for the preferred orientation peak occurred at pH of 2.20. At this pH value, the electrodeposited CuSe layers have the highest crystallite sizes.

Integrating anti-aggregation Ta-Se motifs into copper selenide for fast and robust sodium-ion storage.

We report a novel bimetallic selenide Cu3TaSe4 anode for sodium-ion batteries synthesized via a one-step solid-state method. The integration of Ta-Se motifs into copper selenide forms a cubic grid structure that prevents copper atom aggregation and mitigates electrode failure. Cu3TaSe4 exhibits a high specific capacity of 305 mAh g-1 at 1 C, excellent rate performance of 286 mAh g-1 at 50 C, and superior cycling stability with 272 mAh g-1 after 3500 cycles at 20 C. This work demonstrates the potential of bimetallic selenides in enhancing sodium-ion battery performance.

Investigating the Effect of Ph Variation on the Optoelectronic and Structural Properties of Electrodeposited Copper Selenide Thin Films.

Copper Selenide (CuSe) thin film compound semiconductors have been deposited onto fluorine doped tin oxide (FTO) conducting substrates using electrodeposition technique through various electrolytic bath pH values of 2.00, 2.20, and 2.40. The deposition was carried out in potentiostatic mode using a 2-electrode system set-up at room temperature for 15 minutes at the cathodic voltage of 500 mV. The electrical and the optical properties of the thin films were carried out using photoelectrochemical (PEC) cells and ultraviolet visible spectrophotometer respectively. CuSe thin film possesses a p-type electrical conductivity and the sample grown at semiconductor and a pH of 2.2 was recorded to have the highest PEC signal and highest photo and dark currents that brings forth its maximum power. The energy band gap values of the electrodeposited CuSe thin films were observed to be 2.30 eV, 2.20 eV, and 2.00 eV at bath pH values of 2.0, 2.2, and 2.4 respectively. The optical band obtained at the various pH decreases as pH increases and these band gap values agree with the bulk band gap of CuSe. The preferred orientation peak of electrodeposited CuSe layers exists as klockmannite (CuSe) and the highest peak intensity for the preferred orientation peak occurred at pH of 2.20. At this pH value, the electrodeposited CuSe layers have the highest crystallite sizes.

Synthesis of CuSe/PVP/GO and CuSe/MWCNTs for their applications as nonenzymatic electrochemical glucose biosensors.

Copper selenide (CuSe) is an inorganic binary compound which exhibits metallic behavior with zero band gap. CuSe has multiple applications in electrocatalysis, photothermal therapy, flexible electronic and solar cells. In the current study, copper selenide based nanocomposites CuSe/PVP/GO and CuSe/MWCNTs were synthesized by using the sol-gel method for application as a non-enzymatic glucose biosensor. Different characterization methods were employed, such as X-ray diffraction (XRD), photoluminescence (PL), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-Vis) spectroscopy, and photoluminescence for determining various aspects of CuSe/PVP/GO and CuSe/MWCNTs nanocomposites including phase formation, functional group analysis, band gaps and morphology. Electrochemical impedance spectroscopy (EIS) showed that the resistances of modified electrode/bare electrode were 12.3 kΩ/17.3 kΩ and 6.3 kΩ/17.3 kΩ for CuSe/PVP/GO and CuSe/MWCNTs nanocomposites, respectively. Cyclic voltammetry showed that both CuSe/PVP/GO and CuSe/MWCNTs nanocomposites are promising biosensors for detection and monitoring of the glucose level in an analyte. The sensitivity and limit of detection are 2328 μA mM-1 cm-2/0.2 μM and 4157 μA mM-1 cm-2/0.3 μM for CuSe/PVP/GO and CuSe/MWCNTs, respectively. Chronoamperometry confirmed that our nanocomposite was the best sensor for glucose even in the presence of other interferents like ascorbic acid (AA), uric acid (UA) and dopamine (DA).

Organosulphur and organoselenium compounds as ligands for catalytic systems in the Sonogashira coupling.

Sonogashira coupling is a reaction of aryl/vinyl halides with terminal alkynes. It is used for the synthesis of conjugated enynes. Generally, copper (Cu) is required as a mediator for this reaction. It requires a long reaction time, high catalyst loading, or expensive ligands. Recently, homogeneous, heterogeneous, and nanocatalysts have been developed using organosulphur and organoselenium compounds as building blocks. Preformed complexes of metals with organosulphur and organoselenium ligands are used for homogeneous catalysis. Heterogeneous catalytic systems have also been developed using Cu, Pd, and Ni as metals. The nanocatalytic systems (synthesized using such ligands) include copper selenides and stabilized palladium(0) nanospecies. This article aims to cover the developments in the field of the processes and techniques used so far to generate catalytically relevant organic ligands having sulphur or selenium donor sites, the utility of such ligands in the syntheses of homogeneous, heterogeneous, and nanocatalytic systems, and critical analysis of their application in the catalysis of this coupling reaction. The results of catalysis are analyzed in terms of the effects of the S/Se donor, halogen atom of aryl halide, the effect of the presence/absence of electron-withdrawing or electron-donating groups or substituents on the aromatic ring of haloarenes/substituted phenylacetylenes, as well as the position (ortho or para) of the substitution. Substrate scope is discussed for all the kinds of catalysis. The supremacy of heterogeneous and nanocatalytic systems indicates promising future prospects.

Precise synthesis of copper selenide nanowires with tailored Cu vacancies through photo-induced reduction for thermoelectric applications

We have successfully synthesized Cu2+xSe nanowires (NWs) with various amounts of Cu vacancies at room temperature by the photoreduction method for thermoelectric applications.

Spectra of optical constants of copper selenide thin films obtained by vacuum-thermal evaporation method

Spectra of optical constants of copper selenide thin films obtained by vacuum-thermal evaporation method

Recent advances in copper-based materials for robust lithium polysulfides adsorption and catalytic conversion

Lithium–sulfur (Li–S) batteries are considered one of the most promising next-generation secondary batteries owing to their ultrahigh theoretical energy density. However, practical applications are hindered by the shuttle effect of soluble lithium polysulfides (LiPSs) and sluggish redox kinetics, which result in low active material utilization and poor cycling stability. Various copper-based materials have been used to inhibit the shuttle effect of LiPSs, owing to the strong anchoring effect caused by the lithiophilic/sulphilic sites and the accelerated conversion kinetics caused by excellent catalytic activity. This study briefly introduces the working principles of Li–S batteries, followed by a summary of the synthetic methods for copper-based materials. Moreover, the recent research progress in the utilization of various copper-based materials in cathodes and separators of Li–S batteries, including copper oxides, copper sulfides, copper phosphides, copper selenides, copper-based metal-organic frameworks (MOFs), and copper single-atom, are systematically summarized. Subsequently, three strategies to improve the electrochemical performance of copper-based materials through defect engineering, morphology regulation, and synergistic effect of different components are presented. Finally, our perspectives on the future development of copper-based materials are presented, highlighting the major challenges in the rational design and synthesis of high-performance Li–S batteries.