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Kesterite Cu2ZnSnS4 (k-CZTS) nanocrystals have received attention for their tunable optoelectronic properties, as well as the earth abundance of their constituent atoms. However, the phase-pure synthesis of these quaternary NCs is challenging due to their polymorphism, as well as the undesired formation of related binary and ternary impurities. A general synthetic route to tackle this complexity is to pass through intermediate template nanocrystals that direct subsequent cation exchange toward the desired quaternary crystalline phase, particularly those that are thermodynamically disfavored or otherwise synthetically challenging. Here, working within this model multinary system, we achieve control over the formation of three binary copper sulfide polymorphs, cubic digenite (Cu1.8S), hexagonal covellite (CuS), and monoclinic djurleite (Cu1.94S). Controlled experiments with Cu0 seeds show that selected binary phases can be favored by the identity and stoichiometry of the sulfur precursor alone under otherwise comparable reaction conditions. We then demonstrate that the nature of the Cu2-xS template dictates the final polymorph of the CZTS nanocrystal products. Through digenite, the cation exchange reaction readily yields the k-CZTS phase due to its highly similar anion sublattice. Covellite nanocrystals template the k-CZTS phase but via major structural rearrangement to digenite that requires elevated temperatures in the absence of a strong reducing agent. In contrast, we show that independently synthesized djurleite nanorods template the formation of the wurtzite polymorph (w-CZTS) but with prominent stacking faults in the final product. Applying this refined understanding to the standard one-pot syntheses of k- and w-CZTS nanocrystals, we identify that these reactions are each effectively templated by binary intermediates formed in situ, harnessing their properties to guide the overall synthesis of phase-pure quaternary materials. Our results provide tools for the careful development of tailored nanocrystal syntheses in complex polymorphic systems.

In this work, gallium doped copper sulfide (Ga-doped CuS) nanocrystals were prepared using a solvothermal method. The effects of Ga doping on the crystal structures, chemical composition, morphology, optical properties and thermal performance of copper sulfide (CuS) were investigated. The Ga-doped CuS nanocrystals had a hexagonal structure comparable to that of pure CuS. The Cu+/Cu2+ ratio first decreased and then increased with increasing Ga3+ doping. Both CuS and Ga-doped CuS exhibited nanoplate and nanorod morphologies. The visible transmittance of the Ga-doped CuS films was in the range of 61–77.1%. Importantly, the near-infrared (NIR) shielding performance of the films can be tuned by adjusting the concentration of the Ga dopant. The NIR shielding value of the optimal Ga-doped CuS film was 72.4%, which was approximately 1.5 times as high as that of the pure CuS film. This can be ascribed to the enhanced plasmonic NIR absorption that resulted from an increase in the hole concentration after doping with Ga3+ ions. In the thermal performance test, the Ga-doped CuS film lowered the interior temperature of the heat box by 9.1 °C. Therefore, the integration of good visible transmittance and high NIR shielding performance make the Ga-doped CuS nanocrystals a promising candidate for energy-efficient window coatings.

High charge transfer resistance and low electrocatalytic activity of counter electrodes (CEs) are mainly responsible for the poor photovoltaic performance of quantum-dot-sensitized solar cells (QDSSCs). Herein, a novel strategy has been successfully introduced for the first time to improve the electrocatalytic activity and charge transfer properties of a copper sulfide (CuS) CE by modifying it with the addition of hydrohalic acids (HHA). Through the suitable surface modification of HHA-incorporated CuS CE, the charge transfer from the external circuit to the CE surface was effectively facilitated. The electrochemical analyses suggest that charge transfer resistance is sufficiently reduced at the CE/electrolyte interface by using the HHA-treated CuS CEs. This improvement is mainly attributed to the high electrocatalytic activity of the modified CEs for the reduction of the polysulfide redox couple electrolyte in QDSSCs. The device constructed with TiO2/CdS/CdSe/ZnS photoanodes and the hydrogen-fluoride-treated CuS (HFCuS) CE exhibits a power conversion efficiency of 4.25%, which is considerably higher than that of the device with the bare CuS CE (3.11%). These findings can facilitate the fabrication of highly efficient CEs for next-generation solar cells.

Electrocatalytic alkyne semi-hydrogenation to alkenes with water as the hydrogen source using a low-cost noble-metal-free catalyst is highly desirable but challenging because of their over-hydrogenation to undesired alkanes. Here, we propose that an ideal catalyst should have the appropriate binding energy with active atomic hydrogen (H*) from water electrolysis and a weaker adsorption with an alkene, thus promoting alkyne semi-hydrogenation and avoiding over-hydrogenation. So, surface sulfur-doped and -adsorbed low-coordinated copper nanowire sponges are designedly synthesized via in situ electroreduction of copper sulfide and enable electrocatalytic alkyne semi-hydrogenation with over 99% selectivity using water as the hydrogen source, outperforming a copper counterpart without surface sulfur. Sulfur anion-hydrated cation (S2−-K+(H2O)n) networks between the surface adsorbed S2− and K+ in the KOH electrolyte boost the production of active H* from water electrolysis. And the trace doping of sulfur weakens the alkene adsorption, avoiding over-hydrogenation. Our catalyst also shows wide substrate scopes, up to 99% alkenes selectivity, good reducible groups compatibility, and easily synthesized deuterated alkenes, highlighting the promising potential of this method., Highly selective electrocatalytic semi-hydrogenation of alkynes over a noble-metal-free catalyst is highly desirable. Here, authors synthesize sulfur-containing copper nanowire sponges for selective electrocatalytic alkyne semi-hydrogenation using water as the hydrogen source.

Copper red glaze is considered to be Chinese unique high-temperature copper colored glaze. The sample of Hongwu underglaze red of the Ming Dynasty was analyzed by scanning electron microscopy (SEM), synchrotron radiation micro-X-ray fluorescence spectroscopy (SR-μ-XRF), synchrotron radiation micro-X-ray diffraction (SR-μ-XRD) and transmission electron microscopy (TEM), the results show that there are nano-scale metal copper particles in the diffusion layer of the glaze, and irregular copper sulfide particles at the bottom layer. The presence of metal copper nanoparticles shows the glaze red, but under the influence of black copper sulfide, the appearance of underglaze red is relatively dull and dark. It is assumed that the pigments in Hongwu underglaze red are natural copper ores due to the existence of irregular particles. Referring to the record of "Bright red clay" in ancient literatures, a mixture of cuprite and chalcopyrite are probably the raw materials, the exhaustion of which may be the main reason for the interruption of copper red glaze after the mid-Ming Dynasty.

The hole density of individual copper sulfide nanocrystals (Cu2-xS NCs) is determined from the stoichiometric mismatch (x) between copper and sulfide atoms. Consequently, the electronic properties of the material vary over a range of x. To exploit Cu2-xS NCs in devices, assemblies of NCs are typically required. Herein, we investigate the influence of x, referred to as the stoichiometric doping effect, on the structural, optical, electrical, and thermoelectric properties of electronically coupled Cu2-xS NC assemblies. The doping process is done by immersing the solid NC assemblies into a solution containing a Cu(I) complex for different durations (0-10 min). As Cu+ gradually occupied the copper-deficient sites of Cu2-xS NCs, x could be controlled from 0.9 to less than 0.1. Consequently, the near-infrared (NIR) absorbance of Cu2-xS NC assemblies changes systematically with x. With increasing x, electrical conductivity increased and the Seebeck coefficient decreased systematically, leading to the maximal thermoelectric power factor from a film of Cu2-xS NCs at an optimal doping condition yielding x = 0.1. The physical characteristics of the Cu2-xS NC assemblies investigated herein will provide guidelines for exploiting this emerging class of nanocrystal system based on doping.

Hg(II) ions in wastewater are highly toxic to the environment and human health, yet many materials to remove the ions exhibit lower adsorption efficiency, and few studies report the reuse of Hg(II)-loaded waste materials. Here, a cheap and efficient adsorbent was prepared for the removal of Hg(II) based on corn bracts (CB) loading copper sulfide (CuS), and the Hg(II)-adsorbed material was reused as a photocatalyst. By changing the adsorption variables such as pH, adsorbent dosage, Hg(II) concentration, contact time and coexisting ions, the optimum adsorption conditions were obtained. The study indicated the adsorption capacity and removal rate of CB/CuS reached 249.58 mg/g and 99.83% at pH 6 with 20 mg CB/CuS, 50 mL Hg(II) concentration (100 mg/L) and 60 min, and coexisting ions did not affect the uptake of Hg(II). The adsorption behavior of CB/CuS toward Hg(II) followed pseudo-second-order and Langmuir models, with the theoretical maximum adsorption capacity of 316.46 mg/g. Finally, we explored an alternative strategy to dispose of spent adsorbents by converting the CB/CuS/HgS into a photocatalyst for the degradation of rhodamine B, with a removal rate of 98%. Overall, this work not only develops a promising material for the treatment of Hg(II)-containing wastewater, but opens up a new approach for the use of the waste adsorbent. HIGHLIGHTS Corn bracts as a carrier of CuS was designed for rapid uptake of Hg(II).; The removal rate of the adsorbent could reach 99.83% in only 60 min.; The theoretical maximum could reach 316.46 mg/g.; Coexisting ions had no significant effect on selective Hg(II) ion removal.; The spent adsorbent was used for photodegradation reaction.

The nanostructured carbonaceous materials (CNTs, graphene, and activated carbon) possess excellent conductivity, larger surface area, good chemical stability, and unique structure. Therefore, these materials have great potential to boost the electrochemical performance of the transition metals based pseudocapacitive materials. In this study, the hydrothermal method was used to prepare copper sulfide nanochips. The electrical conductivity and capacitive properties of the fabricated sample were improved by forming their nanohybrid with conductive as well as capacitive CNTs. The morphological, structural, compositional, and electrical behavior of materials was investigated by conducting various analyses. The calculated electrical conductivity value of the nanohybrid sample (2.34 × 102 Sm−1) was considerably higher than the bare sample (1.85 × 10−4 Sm−1), which ensured the existence of a positive association between cobalt sulfide nanochips and one-dimensional CNTs. During electrochemical testing, the nanohybrid sample showed a much better capacitive ability than the pristine cobalt sulfide sample due to its tuned electrical properties, hybrid composition, and constructive interaction between its supplements. More precisely, the nanohybrid sample displayed a good gravimetric capacitance (Cg) (677 Fg-1) at 1 Ag-1 and excellent capacitance retention (81.9%) at 5 Ag-1. Moreover, the nanohybrid sample showed superior cyclic-aptitude as it lost only 17.7% capacity, whereas the pristine metal sulfide sample lost nearly 36% of its initial capacity after 1000 cyclic discharge experiments. The electrochemical results showed that our synthesized sample offer excellent potential for practical application in next-generation electrochemical equipments.

Lignin has been considered to be an ideal carrier for the construction of lignin-based antibacterial materials by its biocompatibility and environmentally benign feature. Herein, lignosulfonate (LS) was utilized as a growth template and a stabilizing agent to synthesize lignin-copper sulfide (LS-CuS) nanocomposites. Interestingly, the as-prepared LS-CuS nanocomposites show enhanced photothermal performance and peroxidase-like activity with near-infrared (NIR) light activation, which benefits highly efficient bacteria-killing via synergistic photothermal–catalytic effects. The bactericidal tests indicated that LS-CuS nanocomposites (100 μg/mL) cause 5.9-log₁₀ and 5.4-log₁₀ CFU/mL reductions against Escherichia coli and Staphylococcus aureus under NIR light irradiation (808 nm, 1.8 W/cm²) for only 5 min in the presence of H₂O₂. Moreover, LS-CuS nanocomposites can be blended with waterborne polyurethane (WPU) to obtain hybrid films, which also achieves a bactericidal efficacy of more than 90% in 5 min. Considering the low cost, easy preparation, and environmental friendliness of LS-CuS nanocomposites, this study may provide new insights into the design of lignin-based inorganic nanocomposites with high bacteria-killing efficiency in a sustainable manner.

In the current paper, copper sulfide nanotubes have been successfully synthesized via the green, simple, and effective gamma-radiolysis method without adding any capping or reducing agents. The structural and morphological characteristics of the as-prepared CuS nanotubes were investigated by X-ray diffraction (XRD), N2 adsorption-desorption measurements at 77 K, transmission electron microscopy (TEM), and ultraviolet-visible (UV-vis) spectroscopy, which all demonstrated the formation of pure CuS covellite phase with tubular morphology. The synthesized CuS nanotubes possessed not only high activity towards the reduction of both cationic (methylene blue) and anionic (Congo red) dyes in the presence of NaBH4 but also exhibited excellent reusability. In addition, the pseudo-first-order kinetic model represented the reduction of MB very well, and the value of the normalized rate constant (2.4 × 10−2 s−1 mg−1) was higher than those of other solid catalysts reported in the literature. Ultimately, CuS nanotubes were found to have a broad-spectrum microbicidal action against the common microbiota, such as Gram-positive (exemplified by Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (exemplified by Pseudomonas aeruginosa and Escherichia coli), yeast (exemplified by Candida albicans), and plant pathogenic fungi (exemplified by Aspergillus niger).

A crucial parameter in the design of semiconductor nanoparticles (NPs) with controllable optical, magnetic, electronic, and catalytic properties is the morphology. Herein, we demonstrate the potential of additive metal cations with variable valency to direct the morphology evolution of copper-deficient Cu2-x S nanoparticles in the process of seed-mediated growth. In particular, the djurleite Cu1.94 S seed could evolve from disk into tetradecahedron in the presence of tin(IV) cations, whereas they merely formed sharp hexagonal nanodisks with tin(II) cations. In addition to djurleite Cu1.94 S, the tin(IV) cations could be generalized to direct the growth of roxbyite Cu1.8 S and covellite CuS nanodisk seeds into tetradecahedra. We further perform pseudomorphic cation exchanges of Cu1.94 S tetradecahedra with Zn2+ and Cd2+ to produce polyhedral zinc sulfide (ZnS) and cadmium sulfide (CdS) NPs. Moreover, we achieve Cu1.8 S/ZnS and Cu1.94 S/CdS tetradecahedral heterostructures via partial cation exchange, which are otherwise inaccessible by traditional synthetic approaches.

The United Nations’ Sustainable Development Goals have sparked growing interest in biosurfactants from many surfactant-loaded industries including those utilizing froth flotation for mineral separation. However, the interaction of biosurfactants with mineral surfaces is currently poorly understood. We bridge this gap by studying adsorption of a yeast-derived bola acidic sophorolipid (ASL) biosurfactant on djurleite (Cu1.94S). The methods used include Hallimond flotation, contact angle, adsorption isotherm, zeta potential, leaching measurements, and X-ray photoelectron spectroscopy (XPS). To facilitate the interpretation of the adsorption results, we characterize the activity of ASL at the air-water interface and measure its critical micelle concentration (CMC) at different pH using static surface tension. We find ASL to be a multifunctional surfactant with an unusual, pH-sensitive interfacial behavior. At the air-water interface, ASL is most active at pH 8, while its CMC goes through minimum as low as 40 μM at pH 7. The surfactant adsorption at the djurleite-water interface makes the sulfide surface hydrophilic at acidic pH and hydrophobic at neutral and basic pH. In addition, ASL has strong affinity to copper sulfide and demonstrates metal leaching properties. Finally, ASL demonstrates detergency properties. We offer a mechanistic interpretation of these findings. Our results provide a basis for the application of acidic glycolipids in froth flotation and have implications for their application in ion separation using hydrometallurgical routes, as well as for the chemical stability of metal sulfides in environmental systems. © 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Electrochemical CO2 reduction can produce valuable products with high energy densities but the process is plagued by poor selectivities and low yields. Propanol represents a challenging product to obtain due to the complicated C3 forming mechanism that requires both stabilization of *C2 intermediates and subsequent C1–C2 coupling. Herein, density function theory calculations revealed that double sulfur vacancies formed on hexagonal copper sulfide can feature as efficient electrocatalytic centers for stabilizing both CO* and OCCO* dimer, and further CO–OCCO coupling to form C3 species, which cannot be realized on CuS with single or no sulfur vacancies. The double sulfur vacancies were then experimentally synthesized by an electrochemical lithium tuning strategy, during which the density of sulfur vacancies was well-tuned by the charge/discharge cycle number. The double sulfur vacancy-rich CuS catalyst exhibited a Faradaic efficiency toward n-propanol of 15.4 ± 1% at −1.05 V versus reversible hydrogen electrode in H-cells, and a high partial current density of 9.9 mA cm−2 at −0.85 V in flow-cells, comparable to the best reported electrochemical CO2 reduction toward n-propanol. Our work suggests an attractive approach to create anion vacancy pairs as catalytic centers for multi-carbon-products. Electrochemical CO2 reduction to the valuable n-propanol is challenging due to the complicated C3 forming mechanism. Here, authors demonstrate double sulfur vacancies formed on hexagonal copper sulfide can serve as efficient electrocatalytic centers.

Due to high affinity and specificity of aptamers, they are widely considered for construction of aptasensor to specific recognizing of analytes in biological complex matrix. So, in this work we design a high selective and sensitive aptasensor for leukemia cancer cells (CCRF-CEM) via superior catalytic effect of copper sulfide-graphene (CuS-GR) nanocomposite as label and Au-GR nanocomposite as sensing platform. The CuS-GR nano-composite (label component) is CuS nanoparticles that wrapping on graphene sheets. Its catalytic activity (CuS-GR) increases the current of sensor in parallel with adding of CCRF-CEM and provide sensitive detection of analytes. The detailed of signal amplification and effect on the aptasensor performance completely discussed. This sensor has a linear range of 50–1 × 106 cell mL−1, with a limit of detection of 18 cell mL−1. Also, the developed aptasensor has a significance specificity, high sensitivity and accuracy. It was used for the identification of CCRF-CEM cells in blood samples.

Hypothesis: The anodic dissolution of chalcopyrite (CuFeS2) encounters the problem of surface passivation, which significantly affects the copper extraction efficiency. So far, there is no agreement on the passivation mechanism and composition of passive layer, which could be studied by using in-situ scanning electrochemical microscopy (SECM). Experiments: SECM was applied for the in-situ probing of chalcopyrite dissolution under mild oxidation potentials. The surface hydrophobicity and nanoscale distribution of hydrophobic domains were analyzed by static water contact angle measurement and atomic force microscope (AFM) force mapping, respectively. The surface conductivity was characterized by SECM feedback mode. Findings: The concentrations of released species Fe2+, Cu2+ and soluble copper sulfide species (CuxS) generally increased with the potential of chalcopyrite. In the active region (low potentials), Fe2+ was preferentially released, and the metal-deficient sulfide layer that was rich in copper relative to iron started to form as the passive layer. While the release of Fe2+ and Cu2+ was impeded in the passive region, the detected CuxS became pronounced in this region and the following transpassive region, which suggested that the existence of CuxS was a result of passive layer dissolution. The nanoscale distribution of hydrophobic domains suggested that the formation of hydrophobic passive layer initiated in the active region and this layer almost completely covered the chalcopyrite surface at the beginning of passive region. The surface conductivity of chalcopyrite decreased with potential due to the formation of less conductive metal-deficient sulfide layer and possibly insulating elemental sulfur (in the transpassive region). This work provides a new approach for the in-situ probing of chalcopyrite dissolution and useful insights into its dissolution kinetics and passivation mechanisms, with implications for similar electrochemical processes of other mineral surfaces.

High-purity copper sulfides including CuS, Cu1.75S and Cu2S were synthesized using an easy and controllable two-step heating method in a mixed solution of ethylene glycol and triethylenetetramine. Petal-like CuS, near-spherical Cu2S, and regular hexagonal Cu1.75S were obtained by simply changing the solvent volume ratio (SVR) of the mixed solution, i.e. the phase of the products solely determined by the SVR of the solution. The influence of the solvent on the final products as well as the reaction mechanism of the system were investigated and discussed. The approach is rapid, easily scalable, and environmentally friendly. As a preliminary application demonstration, dye-sensitized solar cells were assembled using the as-synthesized copper sulfides and photoelectric conversion efficiencies up to 3.62% were achieved.

Paracetamol (PA) is a ubiquitous non-steroidal anti-inflammatory drug, mainly used to treat headaches, arthritis and osteoarthritis and other diseases. In this work, a novel label free photoelectrochemical (PEC) sensor based on Bi–CuS/Bi2WO6 has been developed for the detection of PA, which was fabricated by a simple two-step hydrothermal process. It was found that Bi–CuS/Bi2WO6 with a CuS/Bi2WO6 heterojunction and surface plasmon resonance (SPR) effect of Bi possesses enhanced charge transfer and absorption wavelengths under visible light, particularly when compared to pristine Bi2WO6 films, thus producing an increase in the observed photocurrent. The photocurrent was increased after adding PA. And the photocurrent increment was linear with PA concentration in the range from 0.01–60 μM with a detection limit of 2.12 nM. Moreover, the PEC sensor also exhibited high anti-interference property and acceptable stability. In the present study, a Bi–CuS/Bi2WO6 photoelectrode is considered a promising candidate for carrying out PEC analysis.

A high-performance electrochemical sensing platform based on CuS nano-globules is efficiently developed. The CuS nano-globules are synthesized through a hydrothermal process. All the important physical characteristics of the nanomaterial such as crystal architecture, morphology, topography and composition are investigated. To better demonstrate the electrochemical sensing capability of CuS nano-globules reinforced electrodes, hydroquinone (HQE) is chosen as an analyte. Upon the electrochemical investigation, the CuS-based sensor displayed an enhanced detection limit of 0.135 μM with a linear range of 1–2287 μM. The overall sensing performance of CuS nano-globules-equipped electrode towards HQE is very impressive with good stability and reproducibility. These investigative results evidently indicate the superior electrochemical properties of CuS nano-globules and they can be highly recommended for real-time analysis.

This paper introduces a full study of CuS thin-film deposited on the quartz substrate. Copper sulfide thin films were prepared using the pulsed laser deposition technique and tested before and after the annealing process. The structural, morphological, and optical properties are examined after the deposition process at different energies (500 mJ, 600 mJ, 700 mJ, 800 mJ). The experimental results show that the best optical absorption is achieved at 600 mJ; this value was annealed at different annealing temperatures (300 °C, 350 °C, 400 °C, and 450 °C). The effect of thermal annealing on CuS film was examined to find the thickness range and the absorption behavior between 300 and 1100 nm. The average surface roughness was evaluated and discussed according to decrease with an increase in the annealing temperatures. Absorption and AFM results were studied thoroughly. Copper sulfide Film could find applications in optical devices such as surface plasmon resonance, window coatings, and optical gas sensors.

Three kinds of multifunctional hexagonal copper sulfide crystals were successfully synthesized by adjusting the preparation process in this work. The supercapacitor performance of product-based electrodes was studied by CV, GCD and EIS measurements, respectively, from which the product synthesized at 140° was proved to have the most brilliant cycle stability and notable energy density. The impact of pH on photocatalytic decomposition of MO was investigated and a reasonable photocatalytic degradation mechanism was proposed, which suggested that it is at pH 5 that the surface state of the catalyst is most conducive to the photocatalytic reaction. Furthermore, the result of a 5 cycle test at pH 5 indicated that the degradation rate still remained 80.9%. All the experimental results fully indicated that the synthesized CuS nanostructure possessed potential electrical and optical application value.

Among metals used for CO2 electroreduction in water, Cu appears to be unique in its ability to produce C2+ products like ethylene. Bimetallic combinations of Cu with other metals have been investigated with the goal of steering selectivity via creating a tandem pathway through the CO intermediate or by changing the surface electronic structure. Here, we demonstrate a facile cation exchange method to synthesize Ag/Cu electrocatalysts for CO2 reduction using Cu sulfides as a growth template. Beginning with Cu2−xS nanosheets (C-nano-0, 100 nm lateral dimension, 14 nm thick), varying the Ag+ concentration in the exchange solution produces a gradual change in crystal structure from Cu7S4 to Ag2S, as the Ag/Cu mass ratio varies from 0.3 to 25 (CA-nano-x, x indicating increasing Ag fraction). After cation exchange, the nanosheet morphology remains but with increased shape distortion as the Ag fraction is increased. Interestingly, the control (C-nano-0) and cation exchanged nanosheets have very high faradaic efficiency for producing formate at low overpotential (−0.2 V vs. RHE). The primary effect of Ag incorporation is increased production of C2+ products at −1.0 V vs. RHE compared with C-nano-0, which primarily produces formate. Cation exchange can also be used to modify the surface of Cu foils. A two-step electro-oxidation/sulfurization process was used to form Cu sulfides on Cu foil (C-foil-x) to a depth of a few 10 s of microns. With lower Ag+ concentrations, cation exchange produces uniformly dispersed Ag; however, at higher concentrations, Ag particles nucleate on the surface. During CO2 electroreduction testing, the product distribution for Ag/Cu sulfides on Cu foil (CA-foil-x-y) changes in time with an initial increase in ethylene and methane production followed by a decrease as more H2 is produced. The catalysts undergo a morphology evolution towards a nest-like structure which could be responsible for the change in selectivity. For cation-exchanged nanosheets (CA-nano-x), pre-reduction at negative potentials increases the CO2 reduction selectivity compared to tests of as-synthesized material, although this led to the aggregation of nanosheets into filaments. Both types of bimetallic catalysts are capable of selective reduction of CO2 to multi-carbon products, although the optimal configurations appear to be metastable.

Electrochemical hydrogen-storage is one of the prominent energy storage systems. In this work, the hydrothermally synthesized copper sulfide (Cu2S) revealed a unique morphology of micro-hexagons as envisioned through scanning electron microscopy measurements. Electrochemical hydrogen storage (EHS) performance was evaluated using various electrochemical techniques, such as cyclic voltammetry, galvanostatic charge-discharge, and impedance spectroscopy measurements. The hydrogen discharge capacity of ~59.32 mAh g−1 was obtained at an applied current density of 1 A g−1. Further, the analysis of the charge-storage mechanism indicates foremost contributions from the redox processes. The prominent hydrogen storage performance is complimented with reasonable cyclic retention for 2500 cycles.

Copper selenide has been considered as a much more promising conversion-type cathode material for rechargeable magnesium batteries than copper sulfide because of its better conductivity. However, the magnesium ion diffusion in the lattice of the CuSe host is subject to a great coulombic resistance due to the relatively high charge density and ion polarization of the divalent Mg2+, leading to undesired rate capability and low reversible capacity. Herein, a morphology engineering strategy is presented to construct sheet-assembled hollow CuSe nanocubes by a simple template-directed selenation reaction at room temperature. Electrochemical measurements suggest that the CuSe nanocubes could exhibit an ultra-high initial discharge capacity of 596 mA h g−1 and maximum specific capacity of 252 mA h g−1 and maintain a relatively high reversible capacity of 170 mA h g−1 after 100 cycles at 200 mA g−1. Furthermore, a remarkable rate capability could be obtained with 77.6 mA h g−1 discharge capacity at 5 A g−1. Additionally, the CuSe nanocubes exhibit excellent compatibility with Mg(BH4)2/(CF3)2CHOH/DME electrolyte and follow a two-step conversion mechanism. Such superior magnesium storage properties demonstrate that constructing a hierarchical hollow structure could be one of the effective methods to promote the magnesium storage kinetics of CuSe cathode materials.

Electrochemical nitrogen reduction reaction (NRR) is a promising method for energy-efficient and low-emission NH3 production. Herein, we report electrochemical NH3 production using a copper sulfide...

Recently, various phases of CuxS (1 ≤ x ≤ 2) were extensively explored as superb counter electrode (CE) materials for quantum dot-sensitized solar cells (QDSSCs). Herein, hexagonal covellite CuS (HC-CuS) with hierarchical nanostructure was grown on porous Ti substrates by chemical bath deposition, and then heat treated in the temperature range of 150–450 °C under N2 atmosphere. The reaction process and the evolution of morphology, composition and crystalline structure of CuxS with the variation of heat treatment temperature were studied by XRD, SEM, EDX, TEM and XPS. The photovoltaic properties of TiO2/CdS/CdSe QDSSCs based on CuxS CEs showed an obvious dependence on the element stoichiometry and crystalline structure of the CuxS. With HC-Cu1.28S heat-treated at 230 °C as CEs, QDSSCs achieved a power conversion efficiency of 3.88% under one sun illumination (100 mW cm−2, AM 1.5 G), which was higher than the counterparts with other compositions. Electrochemical impedance spectroscopy, Tafel polarization and cyclic voltammetry measurement showed that the electrocatalytic activity of HC-Cu1.28S CE was much higher than that of other CuxS CEs, which supported the results of the enhanced short-circuit current density, open circuit voltage and filling factor.

Although the intriguing plasmonic properties of noble metal nanoparticles originate from the collective oscillations of free electrons in the conduction band, nanoparticles of doped semiconductors may also exhibit metal-like, plasmonic features that are dictated by the resonantly excited free hole oscillations in the valence band. Here, we combine Au, a representative free electron metal, with copper sulfides, a class of plasmonic p-type semiconductors, in a core-shell nanoparticle geometry to construct dual-plasmonic hetero-nanostructures displaying unique multiplex optical characteristics dominated by plasmonic hole oscillations in the semiconductor shells, plasmonic electron oscillations in the metallic cores, and interband electronic transitions from the valence to conduction bands. Through deliberately designed colloidal synthesis, we are able to selectively grow nanoshells comprising copper sulfides of specifically targeted crystalline phases and Cu/S stoichiometries, such as covellite (CuS), digenite (Cu1.8S), and nonstoichiometric Cu2-xS, on the surfaces of Au nanoparticle cores. Our synthetic approach enables us not only to finely control the core and shell dimensions but also to systematically adjust the free hole concentrations in the semiconductor shells, which forms the keystone for the fine tuning of multiple optical resonance modes supported by these hybrid hetero-nanostructures. The dual-plasmonic Au@copper sulfide core-shell nanoparticles exhibit unique multimodal photothermal and photocatalytic behaviors upon selective photoexcitations of different optical transitions at their characteristic resonant frequencies, allowing us to quantitatively evaluate and rigorously compare the intrinsic photothermal and photocatalytic efficacies of multiple types of hot charge carriers, all photoexcited in the same hybrid nanoparticles but with distinct photophysical origins, excited-state lifetimes, energy distributions, and transfer pathways.

Copper sulfide and zinc sulfide nanostructures were synthesized using a solvo/hydrothermal method and a thio Schiff base ligand, N-benzylidene ethanethioamide, as a source of sulfide ions. The effects of different synthesis parameters including the type of solvent, temperature, and duration of reactions on the morphology of the CuS and ZnS products were investigated using field emission scanning microscopy and transmission electron microscopy, respectively. The structural aspects of the samples were characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive X-ray analysis. The optical properties of the samples were studied through their optical absorption and photoluminescence spectra. The photocatalytic ability of the as-synthesized sulfides was explored by studying the colour removal of methylene blue under ultraviolet light irradiation.

Plate-like CuS particles were prepared by a facile chemical synthesis method. The effects of thiourea contents on phase, morphology and electrochemical properties were studied by modern characterization techniques. A mechanism was proposed for morphology evolution from spherical to plate-like with the increase of amounts of thiourea. The precipitation of [Cu4(tu)9](NO3)4·4H2O complex was postulated as a reason for the crystallization of plate-like CuS particles which showed a pseudocapacitor behavior with a specific capacitance of 517 F g−1 at a current density of 1 A g−1. The appropriate electrochemical characteristics were attributed to the unique structure of plate-like CuS particles, improving the charge transport and electrolyte diffusion.

The composite material composed of zinc sulfide, copper sulfide and porous carbon is prepared in this study, exhibiting excellent performances in the field of supercapacitor electrode and photocatalysts. In the degradation process of organic pollutants, zinc sulfide/copper sulfide with heterostructure effectively reduce the recombination rate of photo-generated electron-hole pairs. And the porous carbon substrate can not only accelerate the separation of photo-carriers but also provide numerous active sites. Furthermore, the sample can be easily separated after decomposing the organic pollutants. As a supercapacitor electrode, the combination of zinc sulfide/copper sulfide with large pseudo-capacitance and porous carbon material with excellent double-layer capacitance results in superior electrochemical performances. The composite electrode shows a high specific capacitance of 1925 mF cm−2/0.53 mAh cm−2 at 4 mA cm−2. And the symmetric flexible supercapacitor based on the composite electrode achieves an outstanding energy density (0.39 Wh cm−2 at the power density of 4.32 W cm−2). Therefore, the zinc sulfide/copper sulfide/porous carbonized cotton nanocomposites (pCZCS) prepared herein exhibit dual functions of photocatalysts with high efficiency as well as energy storage materials with high energy density, which is interesting and important for expanding the practical applications in cross fields.

Electrochemical hydrogen evolution reaction (HER) using non-precious compounds has gained substantial interest in the development of water electrolyzers. Herein, we report the synthesis of Copper sulfide (Cu2S) micro-hexagons via a hydrothermal method, followed by some of the important physiochemical characterizations and electrochemical measurements towards the HER. Cu2S micro-hexagons could catalyze the HER in both basic (1 M KOH) and acidic solutions (0.5 M H2SO4), corresponding to the extreme pH values of 14 and 0, respectively. As manifested from the polarization curve, Cu2S micro-hexagons required an overpotential of −330 mV and −312 mV to deliver a benchmark catalytic current density of 10 mA cm−2 in basic and acidic solutions, respectively. Furthermore, lower overpotentials are complemented with the prominent long-term stability of 24 h, as evident from chronopotentiometric analysis. The superior electrochemical performance of these Cu2S micro-hexagons demonstrates their promising suitability for water-splitting applications.

In this research, flotation of copper, lead and zinc minerals from a copper oxide–sulfide ore was studied. The identification tests showed that the sample is a mixture of quartz, chalcopyrite, galena, cerussite, hemimorphite and iron oxide minerals with 5.04% CuO, 1.61% PbO, 2.07% ZnO and 56.40% SiO2. The experimental design methodology (RSM) was conducted to investigate the effect of parameters such as pH, collector, depressant, dispersant, preparation time and size of particles on Cu–Pb–Zn minerals flotation in three steps: sulfide bulk flotation, oxide bulk flotation and sulfide differential flotation. The experiments showed that the pH, potassium amyl xanthate and sodium silicate variation influence copper, lead and zinc recoveries. In the first step, recovery of Cu–Pb sulfide reached 45.49% with grade of 15.96% for Cu and 61.65% with grade of 7.4% for Pb. In the third step, the recovery and grade of Cu enhanced to 88% and 18.3%, respectively. The optimization of parameters was conducted by software, and the supplementary tests were done by considering the optimal conditions. Under optimal conditions, the recovery of copper and lead was, respectively, 88% with grade of 24.5% in Cu concentrate and 81% with grade of 13.8% in Pb concentrate.

The electrochemical nitrogen reduction reaction (NRR) has been regarded as a promising alternative to the conventional Haber-Bosh process for NH3 synthesis. Inspired by the Fe-Mo-S cofactor in the ...

Cation exchange reactions of colloidal copper sulfide nanoparticles are widely used to produce derivative nanoparticles having unique compositions, metastable crystal structures, and complex heterostructures. The copper sulfide crystal structure plays a key role in the mechanism by which cation exchange occurs and the product that forms. Here, we show that digenite copper sulfide nanoparticles undergo a spontaneous phase transition to tetragonal chalcocite in situ, prior to the onset of cation exchange. Room-temperature sonication of digenite (Cu1.8S) in trioctylphosphine, a Lewis base that drives cation exchange, extracts sulfur to produce tetragonal chalcocite (Cu2S). The subtle structural differences between digenite and tetragonal chalcocite are believed to influence the accessibility of cation diffusion channels and concomitantly the mechanism of cation exchange. Structural relationships in nanocrystal cation exchange are therefore dynamic, and intermediates generated in situ must be considered.

A straightforward process for synthesis of hybrid porous electrode material composed of reduced graphene oxide (rGO) and copper sulfide (CuS) with layered structure on the stainless steel substrate is developed. As-synthesized hybrid electrode shows hexagonal crystal structure of CuS with 77 m2 gm−1 specific surface area and 22 nm average pore size. The specific capacitance obtained with rGO-CuS5 hybrid electrode is 1201 F g−1 at the sweep rate of 5 mV s−1 in 1 M LiClO4 aqueous electrolyte. The majority of charge stored by diffusion-controlled process indicates benefits of layered structures for solid-state energy storage. The rGO-CuS5-based hybrid symmetric supercapacitor delivers a specific capacitance (Cs) as high as 109 F g−1 at a sweep rate of 5 mV s−1 with polyvinyl alcohol (PVA)-LiClO4 gel electrolyte. Also, the specific energy of 44 Wh kg−1 and specific power of 1.4 kW kg−1 with 87% stability after 6000 cycles at an applied current of 5 mA are obtained. The simple process of synthesis of layered hybrid electrode material for flexible supercapacitor promises its use in smart textile and wearable electronic devices.

Made available in DSpace on 2020-12-12T01:27:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) A switching memory device based on functionalized gold nanoparticles (AuNPs) and hexagonal copper sulfide nanocrystals (CuS), finely blended in polymethylmethacrylate matrix (PMMA), is herein presented. A two-electrode sandwich architecture has been implemented using aluminum top and bottom electrodes and a polymeric insulating layer based on PMMA/AuNPs/CuS. The device showed memory storage capabilities suitable for (Read Only Memory) ROM applications and behaves as a typical Write-Once, Read-Many-times (WORM) device. The results obtained with the blend containing AuNPs and/or CuS were compared with pure PMMA. By a voltage ramp in the range ± 9 V, it was possible to permanently change the electrical resistance between the electrodes yielding an ON/OFF current ratio above 105 with long-term stability over the whole experiment duration (30 days). Department of Chemistry University of Rome Sapienza, P.le A. Moro 5 POSMAT – Post-Graduate Program in Materials Science and Technology School of Sciences UNESP – São Paulo State University Department of Physics School of Sciences UNESP – São Paulo State University POSMAT – Post-Graduate Program in Materials Science and Technology School of Sciences UNESP – São Paulo State University Department of Physics School of Sciences UNESP – São Paulo State University CAPES: 024/2012 FAPESP: 2013/07396-7 FAPESP: 2016/17302-8 FAPESP: 2017/20809-0

In this work, solid spherical and hollow spherical CuS were prepared by microwave assisted method with PEG4000 as dispersant. The CuS was characterized by particle size analysis, scanning electron microscope(SEM), nitrogen adsorption and desorption, and X-ray diffraction (XRD), respectively. The effects of PEG4000, ratio of thiourea: copper, and microwave power on particle size of CuS were discussed, and the effects of particle size on photocatalytic property were evaluated. The solid spherical CuS had average particle size of 189.1 nm and specific surface of 9.54 m2/g. The hollow spherical CuS had average particle size of 502.7 nm and specific surface area of 16.01 m2/g. The results showed the hollow spherical CuS had better photocatalytic property. In addition, the cotton fabric was treated by hollow spherical CuS/polydimethylsiloxane (PDMS) to prepare multifunctional textile in this work. The treated cotton fabric was characterized by SEM. The treated cotton fabric achieved the superhydrophobicity with contact angle of 156.9° and sliding angle of 8°, good photocatalytic properties for methylene blue, and exceptional UV resistance with UPF of 223.52.

Lithium metal has been regarded as the ultimate anode for next-generation rechargeable batteries with high energy density. However, its high reactivity and dendrite growth seriously limit its commercial application, which can be well addressed by realizing uniform Li deposition. Here, we report a facile and scalable one-step vulcanization method to modify commercial Cu foil with lithophilic Cu2S. The in situ formed Cu2S layer can not only promote the homogeneous deposition of Li via its lithophilic nature, but also benefit the formation of a stable solid-electrolyte interphase during initial activation. The Cu2S-modified Cu current collector realizes dendrite-free Li plating/stripping and thus exhibits stable cycling performance with a high Coulombic efficiency, even with a large capacity of 4 mA h cm−2. A full-cell consisting of a Cu2S/Cu-Li anode and a LiFePO4 cathode exhibits greatly improved cycling stability and enhanced Coulombic efficiency, demonstrating the effectiveness and practicability of the proposed Cu2S/Cu foil in the field of rechargeable Li metal batteries.

Antibacterial nanomaterials have attracted growing interest for bacterial infection therapy. However, most nanomaterials eliminate bacteria either physically or chemically, which hampers their efficacy when dealing with multidrug-resistant bacteria. To overcome this, we integrated copper sulfide (CuS) nanoparticles with active graphene oxide nanosheets (GO NSs) to synthesize a superior nanocomposite (CuS/GO NC) that acts both physically and chemically on the bacteria. CuS/GO NC was produced using a facile hydrothermal method, whereby the CuS nanoparticles grew and were uniformly dispersed on the GO NSs in situ. We found that the CuS/GO NC possesses a unique needle-like morphology that physically damages the bacterial cell membrane. CuS/GO NC also exhibits high oxidase- and peroxidase-like activity, ensuring efficient generation of the reactive oxygen species •OH from H2O2, which kills bacteria chemically. These features endow the CuS/GO NC with excellent antibacterial capabilities to kill multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) with only a single dose. Additionally, it was found that the CuS/GO NC accelerated the healing of infected wounds in vivo owing to its good biocompatibility as well as facilitation of cell migration and collagen secretion. This study provides a new strategy to combine the physical and chemical antibacterial modes of nanomaterials to develop more effective therapies to combat multidrug-resistant bacterial infections.

BACKGROUND Significant efforts have been devoted to examine the adsorption of flotation surfactants in both mechanistic studies and process implementations. However, quantitative electrochemical methods for flotation surfactant adsorption examination have not been well-established, despite of their low-cost, accurate, in-situ nature.RESULTS In this paper, voltametric measurement was proven to quantitatively examine the adsorption of activating copper and lead ions onto a pyrite surface. The activation was achieved by abrading minerals in a heavy-metal-bearing solution and the measurements were performed by transferring the minerals to a solution free of those heavy metals. This provided a simple but realistic simulation of the mineral grinding process and simplified the adsorption quantification by excluding any other irrelevant electrochemical reactions near the surface. Reliable electrochemical impedance spectroscopy (EIS) upon adsorption with convincing physical models for interpreting the interfacial structures also were obtained in this paper. The additional pseudocapacitive behaviour of the copper sulfide surface layer led to an increased capacitance of the measured EIS. A resistive but ion-permeable xanthate adsorption layer exhibited its own relaxation process. Voltammetry and impedance studies showed that cyanide competed with both copper and lead for their adsorption, whereas lead activation showed greater tolerance to cyanide than copper did.CONCLUSION Electrochemical methods have been established to examine the adsorption of copper, lead and xanthate onto pyrite surface, in relation to various flotation conditions, which exhibited significant implication to the flotation of pyritic gold ore using cyanide-bearing water. (c) 2020 Society of Chemical Industry

The corrosion behavior of copper electrode in unpolluted and sulfide polluted synthetic seawater (SSW) was carried out. It was demonstrated that the coexistence of sulfide and dissolved dioxygen in seawater leads to an increase in the anodic and cathodic current densities. However, the addition of chitosan polymer as corrosion inhibitor resulted in a significant decrease in the anodic as well as cathodic current densities. The immersion of copper sample in the sulfide-polluted seawater resulted in the formation of a copper sulfide layer on the metal surface. It was observed that the copper sulfide formed on copper foam immersed in sulfide-polluted seawater affects the oxygen reduction reaction (ORR) and, therefore, the entire corrosion mechanism. The copper sulfide film was also obtained on the copper electrodes following electrodeposition method (chronoamperometry). The deposited film increased the diffusion-limiting current suggesting the diffusion-controlled mechanism of the ORR. The presence of chitosan decreased the current density and the rate of oxygen reduction in the synthetic seawater solution. Keywords: Catalytic activity, Corrosion inhibition, Oxygen reduction, Cathodic reaction, Sulfide polluted synthetic seawater, Electrodeposition

Construction of well-defined hybrid composites consisting of transition metal sulfides and two-dimensional (2D) carbon nanosheets as high-performance anodes for lithium-ion batteries (LIBs) is of great significance but remains challenging. Herein, we have developed a novel strategy to in-situ fabricate a nanohybrid composites consisting of cobalt-doped copper sulfides nanoparticles embedded in 2D carbon nanosheets (2D Co-Cu2S@C) through a one-pot sulfurization of 2D nanosheet-like Co-doped copper-based metal-organic frameworks (MOFs) precursors. When applied as LIBs anodes, the as-prepared 2D Co-Cu2S@C composites could deliver a specific capacity of 780 mAh g-1 at 0.5 A g-1 after 300 cycles and a high-rate capability with 209 mAh g-1 at 5 A g-1, superior to most reported copper sulfide-based anodes. The exceptional performance could be attributed to the synergism of ultrathin structure (~4 nm), appropriate cobalt doping and strong carbon coupling, resulting in the shortened paths for Li+ transportation, enlarged exposing surface for Li+ adsorption, enhanced electric conductivity for charge transfer as well as robust mechanical property against volume expansion.

Magnesium (Mg) metal anode pairing with Sulfur (S) cathode has been regarded as a promising contender for next-generation battery technology holding the characteristics of safety in use, low cost and high energy density. However, the sluggish kinetic and the inferior reversibility of Mg–S electrochemical reaction are two main challenges impeding the development of practical Mg–S batteries. Herein, SeS2 is proposed as a superior cathode for Mg batteries based on the complementary features of S (high specific capacity) and Se (high electronic conductivity). In this designed Mg–SeS2 battery with a Cu foam interlayer between cathode and separator, SeS2 compositing with ordered mesoporous carbon (SeS2/CMK3) exhibits impressive electrochemical performance. Various characterizations towards the electrochemical evolution on cathode side reveal that Cu foam interlayer not only acts as the trapping layer by the rapid chemical immobilization of polysulfide (polyselenide) species on Cu foam, but also serves as a “promoter” to propel the overall charge-discharge kinetics by the reversible displacement reaction between copper sulfide (copper selenide) and Mg2+. Benefiting from the unique advantages of SeS2/CMK3 and the rationally designed Cu interlayer, this novel Mg–SeS2 system demonstrates a feasible strategy to exploit the rechargeable Mg batteries with low cost, high areal capacity and large current capability.

We have investigated the chemical bath deposition (CBD) of CuS using thioacetamide on functionalized self-assembled monolayers (SAMs) using scanning electron and optical microscopies, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry. For all SAMs studied, the amount of CuS deposited is strongly dependent on the bath pH and can be attributed to the interaction of the SAM terminal groups with the chalcogenide ions present in solution. For -CH3-terminated SAMs, there is a steady increase in the amount of CuS deposited with an increase in the bath pH because there is an increase in the concentration of chalcogenide ion. However, for -OH- and -COOH-terminated SAMs, we observe that the maximum amount of CuS is deposited at pH 10. We attribute this behavior to a competition between the repulsion of the chalcogenide ions by the negatively charged SAM terminal groups and an increase in the chalcogenide ion concentration with an increase in the bath pH. Using the interaction of the chalcogenide ions with the different SAM terminal functional groups, we demonstrate that CuS can be selectively deposited on the -CH3-terminated areas of patterned -OH/-CH3- and -COOH/-CH3-terminated SAMs.

Copper sulfide (CuS) nanoparticles were synthesized by solid-state reaction method under the flow of nitrogen. Polyvinyl alcohol/polyethylene glycol/copper sulfide (PVA/PEG:CuS) nanocomposite films with different concentrations of copper sulfide nanoparticles (1%, 3%, 5%) were prepared using casting technique. Structural and morphological properties of the prepared nano samples were investigated using X-ray diffraction data (XRD), transmission electron microscope and energy dispersive spectrometry techniques. The formation of nanocomposite films was confirmed by both XRD and fourier transform infrared techniques. Calculated and measured nano material particle size is almost similar. The characteristic peaks of nanocomposite films were found to be shifted towards higher wavenumber. The thermal stability behavior of row (PVA/PEG) blends and (PVA/PEG:CuS) nanocomposite films was examined using the thermogravimetric analysis technique. Samples doped with 5% CuS concentration revealed the highest thermal stability. The optical properties of undoped and nanocomposite films have been discussed in details using UV–Vis spectrophotometer. The optical transmittance revealed an apparent decrease (more than 40% for films doped 5% CuS). Different optical constants and dispersion parameters were discussed in detail and proved to be directly affected by nano doping concentrations. The optical energy gap values of polymer films decreased from 5.3 to 3.3 eV with the CuS nanoparticles incorporation. The study of the PVA/PEG nanocomposite films based on CuS nanoparticles has not been previously discussed. Therefore, this study is considered a new piece of work.

A new copper-thiolate cluster assembled framework [Cu2(µ4-SCH3)Cl]n (1), has been solvothermally synthesized through in situ reaction viz., in situ ligand generation and metal reduction. Compound 1 represents the first 3D framework based on Atlas-sphere functionalized by single µ2-Cl− groups. DOS calculation reveals the interaction of electronic structures. It is found that the HOMO is mainly distributed on Cl, Cu and S bonding orbitals, while the LUMO is dominated by Cu-Cl antibonding orbitals.

Wastewater remediation by nanostructured photocatalysts represents a critical issue for nanotechnology. In this work, we employed a facile, low-cost, and one-pot co-precipitation strategy to synthesize a pure hexagonal phase of copper sulfide (CuS) nanostructures at a relatively lower temperature. The produced CuS investigated using different instrumentation. The results confirmed that CuS crystallized in urchin-like nanostructures with a single hexagonal phase exhibiting a band gap of 2.22 eV. The photocatalytic performance of the prepared CuS examined for the photodegradation of malachite green dye (MG) employing direct sunlight illumination. The outcomes showed that the produced CuS featured photodegradation efficiency of 95.5% and 67.2% mineralization within 90 min. Moreover, the kinetic studies of MG photodegradation and the applicability of CuS photocatalyst displayed a pseudo-first-order reaction with high stability at a decent efficiency. This work opens the door for using only prepared single-phase metal chalcogenides in water remediation under direct sunlight.

Zinc oxide (ZnO) nanorod arrays (NRs)/gold (Au)/copper sulfide (CuS) heterostructures were grown by way of a low-temperature chemical approach, magnetron sputtering deposition and the successive ionic layer absorption and reaction route. The structural characteristics, morphological characteristics, elemental composition, current–voltage characteristics, ultraviolet–visible–near-infrared absorption and photocatalytic and photoelectrochemical properties of the ternary zinc oxide NR/gold/copper sulfide heterostructures were studied. The photocatalytic efficiency of the zinc oxide NRs/gold/copper sulfide heterostructures was higher than that of their zinc oxide NRs/copper sulfide counterparts. The zinc oxide NRs/gold/copper sulfide heterostructures were visible-light-photosensitive due to the lower bandgap of copper sulfide and localized surface plasmon resonance excitation of gold. The Schottky junction can motivate the photogenerated electron–hole to separate and transfer in opposite direction. The zinc oxide NRs/gold/copper sulfide heterostructures had a diode-like behavior. The electronic transition can be facilitated between ZnO NRs/gold/copper sulfide heterostructure and 1 M potassium hydroxide (KOH) electrolyte.

Bovine serum albumin-mediated copper sulfide nanocomplex (BSA/CuS) was modified on the mesoporous silica (MSN) loaded with chemotherapeutic drug doxorubicin (DOX) by amide bond to prepare a new drug carrier MSN-DOX@BSA/CuS. The disulfide bond of blocking agent BSA broke down after the redox reaction with glutathione, resulting in the MSN pore exposure and release of DOX. As a photothermal reagent, CuS could convert light energy into heat for photothermal therapy. UV-Vis-NIR absorption spectra were used to investigate the absorption properties of the carrier. The results showed that the carrier had strong absorption in the range of 800–1100 nm and could realize the photothermal conversion under the near infrared light. In addition, MSN@BSA/CuS was incubated with cancer cells and showed no cytotoxicity. When MSN-DOX@BSA/CuS was added, the relative survival rate of the cells decreased to 49%. After the extra laser, only 18% cells survived. The above results showed that the synthesized nano drug carrier could realize the synergistic treatment of photothermal therapy and chemotherapy, and effectively improve the treatment efficiency of cancer.

In this study, copper sulfide (CuS) semiconductor material is combined with a polyvinyl alcohol (PVA) polymer to synthesize a hybrid organic/inorganic thin film, due to their respective intrinsic properties and extensive array of applications in optical and electrical devices. The PVA organic polymer was mixed with three different concentrations of CuS powder (0.002 g, 0.02 g, and 0.2 g), to determine the thickness of emissive layer for light-emitting applications. The structural, morphological, electrical, optical, and photoluminescence (PL) properties of the thin films were examined. The PVA/CuS thin films synthesized from CuS concentration of 0.2 g exhibited the largest grain size (37.3 nm), the highest thickness (17.48 μm), surface roughness (94.6 nm), conductivity (2.8 Ω cm, 7.55 × 103 cm2/V s, and 1.48 × 1014/cm3), the lowest bandgap (3.59 eV) and the strongest emission bands. Thus, concentration of the precursor CuS material influences the structural, morphological, electrical, optical, and photoluminescence properties of organic/inorganic thin films. In addition, FTIR and PL spectra confirmed the miscibility/bonding of PVA polymer with CuS semiconductor material and exhibited the emission bands of the films, respectively.

Nonvolatile electrical resistive behaviour was demonstrated for a copper sulfide nanoparticle decorated carbon nitride (CSCN) based device. The copper sulfide–carbon nitride composite system was synthesized using a high temperature in situ protocol, where the sulfide particles were highly dispersed on the carbon nitride matrix. The CSCN composite was characterized by using different analytical techniques. The transport mechanism of the device followed Poole–Frenkel (PF) for the OFF-state, whereas ohmic behaviour dominated for the ON-state. An endurance study of the device was performed with a duty-cycle of 50% for 2 × 103 cycles and the nonvolatile behavior of the device was studied with a duty-cycle of 0.16% for 2 × 103 s. Both the endurance and nonvolatile behavior exhibited excellent stability of the device with an ON to OFF ratio of 104.