Hexagonal CuS Research Articles

Copper/Tin Nanocomposites-Loaded Exosomes Induce Apoptosis and Cell Cycle Arrest at G0/G1 Phase in Skin Cancer Cell Line.

This study aims to explore the efficacy of Copper/Tin (CuS/SnS) nanocomposites loaded into exosomes against skin cancer A431 cell line. CuS/SnS nanocomposites (S1, S2, S3) were synthesized and characterized, then loaded into exosomes (Exo) (S1-Exo, S2-Exo and S3-Exo) and characterized. After that, the loaded samples were investigated in vitro against A431 using cytotoxicity, apoptosis, and cell cycle assays. CuS/SnS nanocomposites were indexed to hexagonal CuS structure and orthorhombic α-SnS phase and showed nano-rode shape. The exosomes loaded with nanocomposites were regular and rounded within the size of 120 nm, with no signs of broken exosomes or leakage of their contents. The cytotoxicity assay indicated the enhanced cytotoxic of S1-Exo versus the free nano-form S1 on A431. Interestingly, S1-Exo recorded 1.109 times more than DOX in its anti-skin cancer capacity. Moreover, S1-Exo recorded 40.2 % for early apoptosis and 22.1 % for late apoptosis. Furthermore, it displayed impact in arresting the cancer cell cycle at G0/G1 phase and reducing G2/M phase. Noteworthy, loaded nanocomposites were safe against normal HSF skin cells. In conclusion, the loaded CuS/SnS nanocomposites into the exosomes could be of great potential as anti-skin cancer candidates through induction of apoptosis and promotion of the cell cycle arrest at G0/G1 phase.

Microwave-assisted synthesis of ZnS@CuInxSy for photocatalytic degradation of coloured and non-coloured pollutants

Copper indium sulfide (CuInS2) exhibits strong visible light absorption and thus has the potential for good photocatalytic activity; however, rapid charge recombination limits its practical usage. An intriguing strategy to overcome this issue is to couple CuInS2 with another semiconductor to form a heterojunction, which can improve the charge carrier separation and, hence, enhance the photocatalytic activity. In this study, photocatalysts comprising CuInS2 with a secondary CuS phase (termed CuInxSy) and CuInxSy loaded with ZnS (termed ZnS@CuInxSy) were synthesized via a microwave-assisted method. Structural and morphological characterization revealed that the ZnS@CuInxSy photocatalyst comprised tetragonal CuInS2 containing a secondary phase of hexagonal CuS, coupled with hexagonal ZnS. The effective band gap energy of CuInxSy was widened from 2.23 to 2.71 as the ZnS loading increased from 0 to 30%. The coupling of CuInxSy with ZnS leads to long-lived charge carriers and efficient visible-light harvesting properties, which in turn lead to a remarkably high activity for the photocatalytic degradation of brilliant green (95.6% in 5 h) and conversion of 4-nitrophenol to 4-nitrophenolate ions (95.4% in 5 h). The active species involved in these photocatalytic processes were evaluated using suitable trapping agents. Based on the obtained results, photocatalytic mechanisms are proposed that emphasize the importance of h+, O2•–, and OH− in photocatalytic processes using ZnS@CuInxSy.

Intercalation-Induced Localized Conversion Reaction in h-CuSe for Ultrafast-Rechargeable and Long-Cycling Sodium Metal Battery.

Cathode materials of sodium-based batteries with high specific capacity and fast charge-discharge mode, as well as ultralong reversible cycles at wide applied temperatures, are essential for future development of advanced energy storage system. Developing transition metal selenides with intercalation features provides a new strategy for realizing the above cathode materials. Herein, this work reports a storage mechanism of sodium ion in hexagonal CuSe (h-CuSe) based on the density functional theory (DFT) guidance. This work reveals that the two-dimensional ion intercalation triggers localized redox reaction in the h-CuSe bulk phase, termed intercalation-induced localized conversion (ILC) mechanism, to stabilize the sodium storage structure by forming localized Cu7Se4 transition phase and adjusting the near-edge coordination state of the Cu sites to achieve high reversible capacity and ultra-long cycling life, while allowing rapid charge-discharge cycling over a wide temperature range.

Visible light enhanced selective benzene response of hexagonal atomic structured CuS microcloves

We have reported CuS microcloves (MCs) for highly selective detection of benzene using scanning kelvin probe (SKP) technique. The electron microscopy investigations revealed the formation of clove shaped CuS with a size of about 1–2 µm at 180 °C and 6 h. The time of reaction significantly affected the crystallinity as well as the morphology of resulting CuS materials. The investigations on adsorption behavior of different types of common volatile organic compounds (VOCs) with varying charge and nature revealed an outstanding selectivity towards benzene when compared to other VOCs. The difference in work function between gold tip and sensor surface modified with CuS MCs was decreased under the exposure of light, most likely caused by transfer of electrons to conduction band of CuS under illumination of light. As a result, the CuS MCs showed enhanced photo response in visible light exposure in the presence of benzene. A chemiresistive type sensor device was fabricated using CuS MCs and exposed to benzene vapor in a concentration ranging from 2.8 to 11.2 ppm. The sensitivity was found to be 1.63 × 10-3 ppm−1. Notably, a rapid response time of ∼6 s and recovery time of ∼ 16 s was achieved for the sensor at a benzene concentration of 5.6 ppm at room temperature. Also, considerable and repeatable sensor response was observed for 560 ppb of benzene vapor at 70 °C. Hence, these results suggested that the CuS MCs have huge potential as novel material for selective benzene detection in gas phase towards breath analysis and other environmental monitoring.

Two in one: The use of hexagonal copper sulfide (CuS) nanoparticles as a bifunctional high-performance cathode and as a reinforced electrolyte additive for an all-solid-state lithium battery

All Solid-State Batteries (ASSBs) based on solid polymer electrolytes (SPEs) have improved safety, energy, and power densities than conventional liquid electrolyte-based Lithium-ion batteries (LIBs). However, two significant obstacles still need to be addressed, including the low ionic conductivities and the low interfacial contact between ASSB components. This study involves the fabrication of hexagonal CuS nanoparticles by a one-step hydrothermal method and uses them for both cathode and solid electrolyte formulation functions. The reasonable ionic conductivity of 4.68 × 10−4 S.cm−1 at 60℃ and the instant transport number of 0.86 of the designed CuS filler-incorporated solid electrolyte offered great promise for ASSBs applications. In particular, the CuS filler-incorporated solid electrolyte exhibited ceaseless and prompt Li-ion transportation kinetics and delivered a dendrite resistance capability over 200 cycles of stripping/plating of Li. In addition, the Li metal solid-state battery is also verified using CuS as the cathode and SPE electrolyte (PEO/LiTFSI/CuS SPE) system. It offers an initial discharge capacity of up to 695 mAh/g and keeps an average capacity of ∼ 365 mAh/g after 50 cycles at a current density of 0.5C. Thus, this study introduced a simple but effective solution to mitigate the dendrite problems associated with solid polymer electrolytes by using CuS as a durable inactive filler.

CuS/SnS quantum dot-nanorod composites: Ferromagnetic and gigantic dielectric characteristics

In this study, new CuS/SnS nanocomposites were simply synthesized by coprecipitation route for capacitive energy storage applications. The results of the XRD analysis confirmed the formation of hexagonal CuS and orthorhombic α-SnS phases. The TEM images of CuS/SnS (1:1) and CuS/SnS (1:3) composites showed the formation of quantum dot particles (2–3 nm) besides nanorods particles (length 56–80 nm and diameter 9–16 nm). The TEM images of CuS/SnS (3:1) sample illustrated the formation of only quantum dot particles (2–3 nm). Infrared band gap energies of 0.8, 0.95 and 1.25 eV were measured for CuS/SnS (1:1), CuS/SnS (3:1) and CuS/SnS (1:3) composites, respectively. CuS/SnS (1:1) composite has a wide hysteresis loop until magnetic field of ±3500 Oe with magnetization (Ms) and coercivity (Hc) values of 0.009 emu/g and 1000 Oe, respectively. For CuS/SnS (1:3) composite, the hysteresis loop possesses a semi-ferromagnetic shape with measured magnetization value of 0.018 emu/g and Hc of 551 Oe. The ferromagnetic order can be attributed to defects as well as the surface interface interaction between CuS and SnS particles. Remarkably, CuS/SnS composites exhibit a giant dielectric constant (>106) with low temperature dependent, making them promising compositions for capacitive energy storage applications. At room temperature, CuS/SnS (1:1), CuS/SnS (3:1) and CuS/SnS (1:3) composites possess colossal dielectric constant values of ∼2.9 × 106, 5.5 × 105 and 6.3 × 106 at frequency of 42 Hz, respectively.

Influence of a One-Pot Approach on a Prepared CuS Macro/Nanostructure from Various Molecular Precursors

Nanostructured metal sulfides such as copper sulfide (CUS) form from single-source precursors (SSPs) and are cost-friendly materials that can be used in a one-pot approach with potential applications in dye-sensitizer solar cells (DSCs). This is an attractive pathway that allows the careful control of tailoring the design of the nanostructures with slight variations in the mixture conditions to form uniform nanoparticles and enhance the performance of DSCs. We report on the optical, structural, and morphological properties of CuS as photosensitizers and their application in QDSCs using characterization techniques such as cyclic voltammetry (CV), current–voltage (I-V), UV-Vis spectroscopy (UV-Vis), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), etc. The UV-Vis reveals that the band gap for the three samples is found at 2.05–2.87 eV, confirming them as suitable materials for solar cells. The XRD peaks for the three CuS nanoparticles harmonized very well with hexagonal CuS. The thermal gravimetric (TGA) suitability of the three complexes shows a two-step decomposition within the temperature range of 125–716 °C, with a final residue of 2–4%. CV curves for three samples show that none of the developed metal sulfides exhibits a peak indicative of limited catalytic activity in the iodine electrolyte. The I-V overall energy conversion efficiency (η%) of 4.63% for the CuSb photosensitizer is linked to the wide electronic absorption spectrum and better relative dye loading. The synthesis of photosensitizers from a trioctylphosphine oxide (TOPO) capping agent shows improved efficiency compared to our previous studies, which used hexadecylamine as a coordinating solvent.

Visible-light induced photocatalytic degradation of estrone (E1) with hexagonal copper selenide nanoflakes in water

Steroid hormones, being potent endocrine-disruptors, are a menace to human health and aquatic life. Herein, visible-light induced photocatalytic degradation of estrone (E1) by hexagonal copper selenide (CuSe) nanoflakes has been reported. CuSe was synthesised by a facile and low-temperature (100 oC) co-precipitation method and was characterised. The nanocrystals were of stoichiometric Cu:Se ratio with Se2- and Cu in the + 1/+ 2 mixed-valence state and exhibited laminar, flake-like morphology with a preferred hexagonal close-packed structure (P63/mmc) having average particle size and thickness of 0.229 ± 0.146 µm and 0.05 ± 0.02 µm, respectively. The adsorption isotherms of E1 were linear and the adsorption process was exothermic. The reactivity of E1 under aqueous suspensions of CuSe exposed to visible light exhibited pseudo-first-order kinetics with a rate constant, k, that varied with initial E1 concentration, light power, catalyst dose, and pH. Particularly, k was almost constant over the range pH5–9 but substantially increased as pH rose to 11, while light power and catalyst dose increased k up to a maximum, and the initial concentration reduced k. Surprisingly, CuSe oxidised E1, even in the absence of light, and leached species that were identified and their time-dependency was determined. We concluded that the disappearance of E1 by CuSe is attributed to synergetic effects of adsorption, oxidation by CuSe, and photocatalytic degradation. Supported by liquid-mass spectrometry analysis and molecular chemistry calculations, we also suggested a possible mechanism for E1 degradation. Thus, hexagonal CuSe nanocrystals can be a promising candidate for the treatment of endocrine-disrupting chemicals (EDC)-contaminated wastewaters.

Управляемый синтез текстурированной пленки CuSe(006) вакуумно-термической обработкой пленочной структуры Se/Cu

A nanocomposite film consisting of crystalline CuSe and amorphous selenium (a-Se) was obtained by vacuum-thermal deposition. It has been shown for the first time that thermal heating of a CuSe/a-Se nanocomposite film in vacuum can transform it into a textured CuSe(006) film. It has been established that at a temperature of 438 K, CuSe crystallites grow intensively in the (006) crystallographic plane. Using the X-ray diffraction analysis method and the technique for measuring the electrical resistance of the CuSe/a-Se composite film, the phase transformation temperatures at which monoclinic Se8, trigonal t-Se, orthorhombic CuSe2, and hexagonal CuSe are formed.

Influence of nanocomposite (1-x)CdS/xCuS on optical characteristics of PVA/CMC/PEG blended polymer; effect of ratio (x)

PVA/CMC/PEG blended polymers loaded with (1-x)CdS/xCuS nanocomposites (x = 0, 0.3, 0.5, 0.7, 1) were formed applying the thermolysis and casting techniques. Rietveld analysis of synchrotron x-ray diffraction data measured for (1-x)CdS/xCuS manifested a single hexagonal phase CuS (x = 1.0) and biphasic structure, hexagonal and cubic, for CdS (x = 0.0); composite samples (x = 0.3, 0.5, and 0.7) exhibited the three phases with varied percentages. Average crystallite size for all nanofillers ranged 4–12 nm. The surface morphology and chemical compositions of the different blends were investigated using SEM and EDS techniques. The effect of loading PVA/CMC/PEG blends with multi phases CdS–CuS nanocomposite on the optical linear and nonlinear behaviors was explored using diffused reflectance technique. The direct and indirect optical band gaps (Eg) values determined for PVA/CMC/PEG are 5.62 and 5.18 eV, respectively, which reduced to (4.2, 4.5, 4.47, 4.56, 3.89) and (3.43, 3.9, 3.74, 3.98, 3.18) eV upon loading with (1-x)CdS-xCuS for x = 0, 0.3, 0.5, 0.7, and 1, respectively. The refractive index of all loaded blends increased non monotonically with (x) reached its highest value for λ ≥ 500 nm upon loading with x = 0.0 (CdS). The fluorescence (FL) intensity of the blended polymers nearly quenched upon loading with CuS (x = 1.0) and greatly enhanced for x = 0.5.

Circular dichroism and enantio-selective catalytic effect of copper sulfide

Chiral inorganic nanomaterials provide a platform for a variety of applications. Chiral ligands are commonly used to induce chiroptical activity of nanoparticles through chiral transfer, while few materials have intrinsic chirality and the origins of their chirality are unclear as well. Here, several hexagonal copper sulfide (CuS) structures with achiral morphology which showed negative circular dichroism (CD) signals are reported. Although these CuS structures had variable maximum of anisotropic g-factor, the wavelength dependence of g-factor due to the structure-dependent chiroptical activity were similar for all these CuS structures, indicating that the negative CD activity could derive from some common microstructure in CuS. The simulation based on density functional theory (DFT) and time-dependent DFT (TDDFT) revealed that the CD may originate from (Cu3S3)2 nanostructure existing in hexagonal CuS. The enantio-selective catalysis of these homochiral CuS structure for oxidation of d-DOPA and l-DOPA was also investigated. All samples exhibited preferential catalysis of l-DOPA, which is conducive to distinguishing l-DOPA from d-DOPA. This work not only reveals the origin of CD in CuS inorganic structures with achiral morphology for the first time, but also provides a profound insight of applications of homochiral CuS structures in catalysis.

Composition controllable alga-mediated green synthesis of covellite CuS nanostructure: An efficient photocatalyst for degradation of toxic dye

A facile, convenient and green method has been devised for the synthesis of a covellite phase copper sulfide nanoparticles (CuSNPs) using aqueous extract of a green alga, Chlorella ellipsoidea. The algal phytochemicals are conjectured to have served as both reducing and capping agent. The absorption features in the NIR region of the UV–visible-NIR spectrum confirmed the formation of covellite copper sulfide nanostructures. The FTIR spectrum of the as-synthesized CuSNPs indicated the involvement of functional groups of biomolecule as surface-ligands on the outer surface of the nanoparticle. The XRD reflections were indexed to hexagonal phase covellite CuS structure. The TEM study revealed a predominantly spherical morphology of particle size in the range of 9–23 nm with some agglomeration. The dark field microscope images also confirm the formation of CuS nanoparticles. EDX analysis of the synthesized nanoparticles confirms the presence of only ‘Cu’ and ‘S’ indicating formation of pure CuS nanoparticles. The as-synthesized nanoparticles exhibited excellent photocatalytic property for the degradation of a water soluble toxic methylene blue dye under scattered sunlight. The dye degradation (rate = 0.03692 min−1) was ascertained to be pseudo-first order with regression coefficient, R2 being 0.96884. The photocatalyst is readily recoverable and showed excellent stability even after four cycles.

An investigation on structural, optical and enhanced third order nonlinear optical properties of facilely synthesized Ce:CuS nanosheets

Current work reported facile chemical synthesis of hexagonal covellite CuS nanostructures with 0.0, 1.0, 3.0 and 5.0 wt% cerium doping concentrations. Scherrer’s equation used to determine the crystallites size and preferred orientation of growth plane is found along (110). Raman spectra of CuS nanostructures showed the characteristics sharp peak at the ∼ 472.21 cm−1. SEM images revealed the shape of nanostructures as nanosheets (NSs) for Ce:CuS. The band gap values of Ce:CuS NSs was computed from diffuse reflectance spectra (DRS) using Kubelka-Munk (K-M) theory which was found in range of 1.56–1.85 eV. Red and UV emission band of nanostructures can be seen in Photoluminescence spectra clearly. Third order nonlinear optics were performed by Z-scan techniques via femtosecond fiber pulsed laser. The nonlinear absorption coefficients (β) and nonlinear refractive index (n2) were found in range of 1.14 × 10-8–2.04 × 10-8 cm/W and 1.04 × 10-12–1.38 × 10-12 cm2/W, respectively. The value of third order nonlinear optical susceptibility (χ(3)) was noticed ∼ 3.36 × 10-8–5.48 × 10-8 esu. A significant improvement was observed in χ(3) with Ce incorporation in CuS lattice system. Therefore, Ce doping makes CuS potential nonlinear optical material for modern photonics device applications.

Detergent-free micelle-assisted synthesis of carbon-containing hexagonal CuS nanostructures for efficient supercapacitor electrode materials

This work developed a novel approach to control the nanostructure morphology of carbon-containing hexagonal CuS using a single-step solvothermal process. Herein, copper II hexafluoroacetylacetonate served as the copper source and played an efficient role as a detergent-free micelle-forming substance in the presence of two immiscible liquids (ethylene glycol and carbon disulfide). The latter form of which assisted spherical-like shell assembly of hexagonal carbon-containing CuS. Physical characterization indicated successful carbon and fluorine doping of the hexagonal CuS structures inside bundles of spheres. This innovative construction can efficiently boost the electrochemical properties of the as-prepared material for supercapacitor applications. The prepared electrode exhibited a superior specific capacitance/capacity of 1123 F g−1 (561.5 C g−1) at 1 A g−1 and outstanding cycling stability. The assembled hybrid device displayed remarkable specific energy of 40 W h kg−1 and a maximum specific power of 8.02 kW kg−1. These results indicate the potential of this material as a promising electrode for highly efficient supercapacitors.

Preparation and spectral properties of CuSe/ZnSe core-shell nanomaterials

In this research, first, CuSe nanoparticles (NPs) were synthesized by using the reflux condensation method. Then, a ZnSe shell was grown on the CuSe NPs by using a simple, rapid photochemical approach. Synthesized CuSe/ZnSe core-shell NPs were characterized by means of different analyses, such as X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), UV-visible (UV-Vis) spectroscopy and photoluminescence (PL) spectroscopy. The XRD analysis of the sample shows the formation of core-shell NPs with the structure of hexagonal CuSe and cubic ZnSe. The core-shell structure of the product has been formed and the size of the synthesized core-shell NPs is about 20–50 nm. The band gap of the CuSe/ZnSe core-shell NPs was higher than that for CuSe or ZnSe in bulk. The fluorescence properties were greatly enhanced by successful growth of the ZnSe shell and decreased with the extension of illumination time.

Dual 2D CuSe/g-C3N4 heterostructure for boosting electrocatalytic reduction of CO2

CO2 Reduction Reaction (CO2RR) is an effective route to convert CO2 to value-added products in energy and environment. In this work, a series of CuSe/g-C3N4 electrodes were synthesized by anchoring hexagonal CuSe nanoplates on g-C3N4 nanosheets and used for electrochemical CO2RR. Among the as-prepared electrodes, 50wt% CuSe on g-C3N4 performed the highest Faradaic efficiency of 85.28% to achieve 1.47 times higher than that of the pure CuSe NPs at -1.2 V vs. RHE due to the larger specific area provided by the introduction of planar-structure g-C3N4 NSs and faster electron transfer speed on the interface of CuSe NPs and g-C3N4 NSs. Meanwhile the calculations of density functional theory confirmed the electronic coupling on the electrodes to form an internal electric field between two materials and electron direction from g-C3N4 NSs to CuSe NPs. This work created a novel opportunity for optimizing design of electrode materials to enhance the CO selectivity of CO2RR.

Solvothermal synthesis of CuSe nanoplates for sodium storage

Sodium-ion batteries have emerged as a promising candidate for energy storage devices, due to abundant reserves. Transitional metal selenides have attracted wide attention due to their easy preparation and good electric conductivity. Here, a simple and facile solvothermal method was used to prepare hexagonal CuSe nanoplates without using expensive reagents and complicated processes. The electrochemical performances and underlying reactions of CuSe nanoplates as the anode material for sodium-ion batteries were investigated in detail. CuSe nanoplates are capable of fast Na storage. They deliver a reversible capacity of 183.5 mAh g−1 at a current density of 5 A g−1 and the capacity retention is ~97.4% after 800 cycles at 2 A g−1. Ex-situ X-ray diffraction (XRD) and selected area electron diffraction (SAED) show that CuSe underwent a conversion reaction, leading to Cu2− x Se in the first-charging process that then worked as the active material in the following cycles.

Change in properties upon thermal treatment of copper sulphide powder and thin films

The thermal oxidation of CuS powder was examined under flow of nitrogen and dry air using thermogravimetry/differential thermal analysis. After 473 K, the oxidation of CuS occurred as a weight loss and accompanied with two overlapped exothermic peaks. The melting temperature delayed due to the formation of oxide and sulphate on the surface of the particles. X-ray diffraction revealed that the as-prepared thin films are mixed phases of hexagonal CuS, orthorhombic Cu2S and orthorhombic CuSO4. After annealing at 573 or 773 K, the films oxidized and new orthorhombic Cu8O phase appeared, and its intensity became dominant upon increasing the temperature and time. Nanoparticles morphology was observed for as-prepared films and upon annealing the nanoparticle became more rounded and bigger. The transmittance of the as-prepared films was almost zero over the entire measured range and it increased with increase in the annealing temperature and time, whereas the reflectance decreased. Both refractive and extinction coefficient values decreased with increase in annealing temperature and annealing time, while the bandgap virtually increased. The resistivity of the as-prepared film remained nearly constant until 543 K. Above 543 K the resistivity increased sharply. Negative and positive temperature coefficients in resistivity phenomena were explored in the annealed films and they were strongly dependent on both annealing temperature and time.

Metal–Organic Framework-Derived CuS Nanocages for Selective CO 2 Electroreduction to Formate

Electroreduction of CO2 to target products with high activity and selectivity has techno-economic importance for renewable energy storage and CO2 utilization. Herein, we report a hierarchical CuS h...

Copper sulfide nanoparticles with potential bifunctional properties: supercapacitor and photocatalysis

Pure hexagonal CuS nanoparticles with stable high capacitance and photocatalytic activity were obtained by a mild solvothermal method.