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The construction of efficient and bifunctional electrocatalysts for overall water splitting is necessary but still remains a tremendous challenge owing to their low surface area and sluggish reaction kinetics. Herein, we demonstrate an electrocatalyst with a rough and porous surface morphology, where copper sulfides and oxides could be grown directly on the copper wire (CW) via an in situ corrosion method. Benefitting from its unique lamellar structure and fast charge transfer kinetics, the as-fabricated electrocatalyst presented a low overpotential of 160 mV for the OER at 10 mA cm−2 and overpotential of 230 mV for the HER at 100 mA cm−2. Besides, this electrocatalyst as an electrode exhibited remarkable durability after 1000 cyclic voltammetry (CV) cycles. In short, this work presents a Cu-based electrocatalyst for efficient water splitting, which has seldom been reported to the best of our knowledge, for exploring high-activity non-noble metal catalysts. [ABSTRACT FROM AUTHOR]

Copper sulfides (CuxS) have been considered promising candidates for sodium-ion battery (SIB) anodes because they are environmentally friendly and have large theoretical capacities. Herein, one-dimensional (1D) hollow CuxS nanotubes were obtained via a sacrificial template diffusion process by immersing 1D copper nanowires in thiourea solution. Pure CuS nanotubes were obtained with sulfurization times lasting up to 12 h. The electrochemical properties of the CuxS nanotubes with different sulfurization times were studied, which reveals the better cycling stability and capacity of the CuxS nanotubes with a sulfurization time of 3 h compared with the pure CuS nanotubes due to the larger specific area. However, after modification with CTAB, the hollow CuS nanotubes (with a sulfurization time of 12 h) were able to deliver a high reversible capacity of 470.6 mA h g−1 at 0.2 A g−1 for the 150th cycle due to the increased specific surface area brought about by CTAB modification. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) have been attracting considerable attention due to their large specific surface area and excellent adjustable voids. A one-step solvothermal method is proposed herein to fabricate 3D hollow cage copper cobalt sulfide CuCo2S4via sulfuration and cation exchange reaction based on MOF ZIF-67. The ternary bimetallic material CuCo2S4 not only retains the spatial structure of ZIF-67 but also adjusts the hierarchical hollow structure by adding a Cu "shell". The hollow cage CuCo2S4 can typically exhibit large specific surface areas, expose additional electroactive sites, and shorten ion/electron diffusion paths. The physicochemical characteristics are comprehensively determined using basic characterization techniques. As an electrode material for supercapacitors, CuCo2S4 has a high specific capacitance of 1096.27 F g−1 at a current density of 0.5 A g−1. Furthermore, an asymmetric supercapacitor (CuCo2S4//AC ASC) device is assembled to prove the practical applicability, and the energy and power densities, respectively, reached 87.59 W h kg−1 and 399.65 W kg−1 at 0.5 A g−1. This device retains 95.83% capacity over 5000 cycles at a current density of 10 A g−1. The proposed method provides an optional protocol for designing and fabricating electrode materials with superior electrochemical energy storage properties and exceptional cyclic stability, presenting additional options for future energy storage devices. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Several copper chalcogenide nanoparticles have been investigated as attractive candidates for replacing toxic (lead and cadmium based) and expensive (indium based) semiconductors. Among these materials, copper antimony sulfides present promising physical properties and reduced costs. Despite many works have dealt with the synthesis of these materials, fewer advanced on the formation mechanisms of the nanoparticles. Herein, we use the design of experiments as a tool to identify the role of each synthesis parameter on the composition, particle size, and optical properties of the obtained material. We evaluated synthesis time and temperature, solvent mixture, and two methods: heat up and hot injection. The nanoparticles were characterized by transmission electron microscopy, Raman spectroscopy, X-ray diffraction, UV-vis-NIR absorption spectroscopy and photoluminescence spectroscopy. The reaction time and synthesis method were found as the main factors governing phase compositions and nanoparticle size. [ABSTRACT FROM AUTHOR]

Hexagonal CuS nanosheets and microspheres composed of numerous flakes were successfully prepared by sonochemical and solvothermal methods, respectively. Ultrasonic radiation and templates of Cu(OH)2 nanoribbons play important roles in the growth of CuS nanosheets. The surfactant PVP restricts the diffusion and growth process, inducing the formation of CuS microspheres under solvothermal conditions. Their better crystallinity, larger interlayer distance and incompact structure made the CuS nanosheets more conducive to the transport of sodium ions. Electrochemical studies showed that the nanosheet electrode exhibits better sodium storage performance compared to the CuS microspheres. The higher specific surface area (25.209 m2 g−1) of the CuS nanosheets provides a larger electrode/electrolyte contact area in the sodiation–desodiation process. The first discharge capacity of the CuS nanosheets could reach 398.6 mA h g−1 which is 71.18% of the theoretical capacity (560 mA h g−1). These results indicate that incompact structures have an advantage in storing sodium ions compared with compact structures. [ABSTRACT FROM AUTHOR]

Copper sulfide (Cu2−xS) is a kind of cation deficient transition metal sulfide, which has attracted great interest due to its unique properties that arise from degenerate vacancy-doping, particularly its tunable localized surface plasmon resonance (LSPR) properties. In this work, a range of vacancy-doped Cu2−xS nanocrystals (NCs) (Cu1.2S, Cu1.4S, Cu1.75S, and Cu1.94S NCs) with a size of around 10 nm was prepared with tunable LSPR through a hot injection method. The doping level was manipulated effectively by varying the injection volume of sulfur powder–oleic acid (S–OA) to finely tune the LSPR wavelength. Cu2−xS NCs with four different doping levels were investigated as photocatalysts for degradation of dyes. The Cu1.94S NCs with the highest LSPR energy exhibited the best photocatalytic activity due to the highest free carrier density, presumably influenced by Cu vacancies and the volume of the S–OA solution. Theoretical calculations of the free carrier density of Cu2−xS NCs are consistent with the order of the photocatalytic activity. The results demonstrate that the correlation of the photocatalytic activity with the corresponding concentration of free holes and the LSPR wavelength is of interest, which will provide inspiration for the design of non-noble metal catalysts by regulating the free hole concentration in degenerate p-doped Cu2−xS caused by cation vacancies. [ABSTRACT FROM AUTHOR]

Herein, aluminum-doped copper sulfide (Al-CuS) nanocrystals were prepared by the hydrothermal method. Al3+ was successfully doped into CuS, and the Al-CuS nanocrystals presented a single phase of the covellite structure similar to pure CuS. The optical band gap energy (Eg) of Al-CuS was in the range of 1.74–2.00 eV. Subsequently, to clearly understand the optical properties of the Al-CuS nanocrystals, the Al-CuS nanocrystals were distributed among polyvinyl alcohol (PVA) to fabricate a film with low near-infrared (NIR) light transmittance (800–2500 nm) and high visible-light transmittance (400–800 nm); herein, we demonstrated that the doping of aluminum (Al) into copper sulfide (CuS) nanocrystals enhanced the solar spectral selectivity of these crystals. [ABSTRACT FROM AUTHOR]

Near-infrared plasmonic binary copper-based chalcogenides have found promising applications in photovoltaics and photothermal therapy. Here, we report a facile synthetic protocol for aqueous soluble covellite (CuS) nanocrystals (NCs) at room temperature. In contrast to previously reported routes, the present method involves the reaction of Cu precursors (e.g. CuCl2, Cu(NO3)2, Cu(Ac)2) with sulphur precursors (e.g. Na2S and (NH4)2S) under ambient conditions in the presence of various ligands, requiring neither high temperature and high pressure nor an inert atmosphere. The as-synthesized CuS NCs, without any further ligand exchange, can be readily dispersed in water and exhibit well-defined near-infrared (NIR) plasmon absorbance. The scalability and reproducibility of the present procedure allow for the gram-scale production of CuS NCs in a one-pot reaction, which is elaborated by upscaling the amounts of precursors and solvents/ligands. In particular, when excited with an 806 nm laser (1.2 W cm−2), the aqueous soluble covellite NCs produce significant photothermal heating with a photothermal transduction efficiency of 20.3%, comparable to previously reported binary copper chalcogenides. Combined with good photothermal transduction properties, photostability and synthesis scalability, the present work provides a general and cost-effective synthetic protocol for not only Cu2−xS but also other copper chalcogenides for promising photothermal applications. [ABSTRACT FROM AUTHOR]

Nanostructured materials of various shape and dimension have aroused intensive interests, among which copper(i) sulfide (Cu2S) nanomaterials are of particular prominence. In this work, various nanostructured Cu2S have been facilely prepared via solventless thermolysis, with well-controlled shape and dimension determined by and inherited from the layered structures of the azobenzene-containing single-source copper thiolate mesogenic precursors. The precursors with longer alkyl tails exhibit highly ordered layered liquid crystalline mesophases and retain persistent order up to temperatures beyond the clearing points. Under non-vacuum inert atmosphere or with further elevated temperature, large undulations of the constrained lamellar space result in significantly enhanced diffusion, migration and mass transfer, thus leading to the morphologies changing from one-dimensional (1D) ultrathin nanowires into thickened nanorods then to discrete 2D nanodisks. Based on a variety of modern techniques, especially in situ variable-temperature small angle X-ray scattering (SAXS), an extended universal “layered-precursor to lamellar-nanomaterial” (LPLM) mechanism has been proposed to account for the structural evolution of Cu2S nanomaterials. Our findings provide a novel pathway with clearer mechanism for well-controlled preparation of metal chalcogenides of various dimension and shape. In particular, the ultrathin Cu2S nanowires are anticipated to serve as fascinating semiconducting materials for various promising device applications. [ABSTRACT FROM AUTHOR]

A major factor limiting the performance of nanostructured CuInS2 photovoltaic devices is the current density, pointing to poor charge carrier transport in CuInS2 nanoparticle films. In a typical CuInS2 core/shell structure synthesis, ZnS is typically chosen as a shell material for CuInS2 core passivation, which leads to a significant enhancement of the photoluminescence quantum yield from the CuInS2 nanoparticles. While typically a marker for excellent photovoltaic performance, in this case the increased photoluminescence likely signals increased charge carrier confinement and reduced transport through any thin films fabricated from the nanoparticles. Here we show that replacing the typical divalent Zn cation surface termination with a monovalent Ag cation leads to small improvements in charge carrier transport through nanostructured films. This surface termination intentionally introduces lower energy electronic states directly at the surface of the CuInS2 nanoparticles, reducing charge carrier confinement and thus increasing charge carrier mobility between nanoparticles. The study assessed appropriate Ag molar ratios to be used in synthesis, with an 8% Ag : Cu ratio found to be optimal. The passivation offered by Ag surface termination appears comparable to that from Zn with strong photoluminescence observed in both cases. Slight improvements in the performance of all-solid-state nanoparticle CuInS2 photovoltaic devices are obtained, with current densities in the Ag surface terminated case being increased by just under 10%. These findings outline a potential strategy for the synthesis of type II core–shell CuInS2 quantum dot thin film devices with improved charge transport. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) hierarchical copper sulfide (CuS) microflowers have been successfully constructed by a facile ionic liquid (1-butyl-3-methylimidazolium chloride, [BMIm]Cl)-assisted solvothermal method at a low temperature (65 °C). Covellite CuS assembled into nanoflakes with a thickness of 8–10 nm and a lateral dimension of about 700 nm was obtained by the decomposition of intermediate complex Cu3(TAA)3Cl3 (thioacetamide, TAA) blocks. The ionic liquid (IL) could serve as a solvent, ligand, and structure-directing agent, which played an important role in the morphologies of Cu3(TAA)3Cl3 and CuS. It is found that CuCl could be interacted with [BMIm]Cl, leading to the formation of [BMIm]CuCl2. Furthermore, the CuS crystal growth along the ＜001＞ direction was inhibited by the absorption of alkylimidazolium rings ([BMIm]+) on the (001) facets of CuS. The morphology and size of CuS were controllable by changing the concentration of [BMIm]Cl. Moreover, 3D hierarchical CuS microflowers used as the photocatalyst showed enhanced visible-light photocatalytic activity for the degradation of methylene blue (MB), due to their large specific surface area, mesoporous structure, and advantageous optical properties. This synthetic method could be expanded to prepare other metal chalcogenides, owing to its simple and safe operation, mild reaction conditions, and low cost. [ABSTRACT FROM AUTHOR]

In this study, hollow three-dimensional CuS hierarchical microspheres were prepared via a facile galvanic replacement reaction. The hollow flower-like CuS microspheres were characterized by XRD, Raman, XPS, SEM and TEM techniques, which revealed that numerous nanoflakes were self-assembled to construct hollow flowers. Based on time-dependent experiments, a plausible formation mechanism (galvanic replacement reaction) was proposed. Paraffin-based composites, containing 50 wt% hollow CuS, exhibited outstanding microwave absorption capabilities, which were attributed to the suitable impedance match and dielectric loss. The minimal reflection loss was −17.5 dB and the effective bandwidth was 3.0 GHz with thin absorber thickness of 1.1 mm. In addition, we put forward a novel solution to evaluate the microwave absorption efficiency. The high efficiency microwave absorption properties originate from the electric/dielectric polarization and unique hollow flower-like structure. The hollow structures can adjust the dielectric properties to obtain good impedance matching. Moreover, the two-dimensional flakes and hollow flowers can induce more multiple reflection and scattering, which consumes more microwave energy. This study has led to a novel useful method for the design of hollow structures used as high efficiency microwave absorbers. [ABSTRACT FROM AUTHOR]

In this work, copper sulfide (CuxS) thin films were deposited by photochemical deposition (PCD). Although deposition of CuxS thin films via PCD undergoes both heterogeneous and homogeneous reactions, we were able to determine the process conditions that will promote the heterogeneous surface reaction on the surface of the substrate. COMSOL numerical simulations and MATLAB were used to estimate the final CuS film thickness and the process kinetics based on experimental results under multiple operating conditions. Successful kinetic modeling and parameter estimations were performed by adjusting the parameters of mass transport equations that controlled the proposed reaction mechanism of CuS. Therefore, this model can be used as a tool for kinetic parameter estimation and optimization of metal chalcogenide thin films in a PCD system. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) hierarchical copper sulfide (CuS) microflowers have been successfully constructed by a facile ionic liquid (1-butyl-3-methylimidazolium chloride, [BMIm]Cl)-assisted solvothermal method at a low temperature (65 °C). Covellite CuS assembled into nanoflakes with a thickness of 8–10 nm and a lateral dimension of about 700 nm was obtained by the decomposition of intermediate complex Cu3(TAA)3Cl3 (thioacetamide, TAA) blocks. The ionic liquid (IL) could serve as a solvent, ligand, and structure-directing agent, which played an important role in the morphologies of Cu3(TAA)3Cl3 and CuS. It is found that CuCl could be interacted with [BMIm]Cl, leading to the formation of [BMIm]CuCl2. Furthermore, the CuS crystal growth along the ＜001＞ direction was inhibited by the absorption of alkylimidazolium rings ([BMIm]+) on the (001) facets of CuS. The morphology and size of CuS were controllable by changing the concentration of [BMIm]Cl. Moreover, 3D hierarchical CuS microflowers used as the photocatalyst showed enhanced visible-light photocatalytic activity for the degradation of methylene blue (MB), due to their large specific surface area, mesoporous structure, and advantageous optical properties. This synthetic method could be expanded to prepare other metal chalcogenides, owing to its simple and safe operation, mild reaction conditions, and low cost. [ABSTRACT FROM AUTHOR]

Among different metal chalcogenides, copper sulfides have been extensively studied in the past few years due to their semiconducting and non-toxic nature, making them useful in a wide range of applications from the energy to the biomedical fields. A series of stoichiometric compositions of copper sulfides from Cu-rich, Cu2S to Cu-deficient, CuS2 exist with different crystal structures as well as phases, resulting in different unique properties. The suitable band gap values in the range of 1.2–1.5 eV and unique optoelectronic properties indicate that the material is photocatalytically active and exhibits excellent plasmonic behavior. The material is also known for promising thermoelectric properties, converting waste heat into electricity through the Seebeck effect. The nanodimensional form of copper sulfides promotes their use to a more advanced level, tuning their properties with the size of the materials. In view of this, the present review article is focused on the compositions, phases and crystal structures, and different synthetic methodologies involved in the fabrication of 0D, 1D and 2D nanostructured copper sulfides. Moreover, recent advancements on their use in various applications will also be briefly discussed. [ABSTRACT FROM AUTHOR]

This article describes a complete study of the evolution of composition (from binary to quaternary) and shape (0D–1D) during the synthesis of CZTS nanocrystals. Aliquot studies were used to track the nucleation and growth in the early stages. Distinctive stages are evident in the reaction due to the progressive incorporation of tin and zinc into the primary copper sulfide particles as a result of their differing precursor reactivity. In addition, reaction windows for shape control were devised by tuning the amine concentration, thereby allowing the formation of a diverse range of shape morphologies including nanorods and ellipsoids, as well as atypical tadpole-shaped and P-shaped nanocrystals. Polytypic nanocrystals with wurtzite and zinc blende domains were also achieved by changing the type of metal precursors used initially in the reaction. [ABSTRACT FROM AUTHOR]

Copper sulphide materials have received great attention due to their low bandgap semiconducting properties. As compared to other chalcogenides, few synthetic examples have been reported, and a simple and scalable synthetic method for preparing size- and shape-controlled copper sulphide nanoparticles is required for potential wide application of these materials. Herein, a facile one pot scalable synthetic route has been developed for preparing highly monodisperse djurleite Cu1.94S hexagonal nanoplates. The thermal decomposition of a single precursor CuSCN was found suitable for preparing a large quantity of highly monodisperse Cu1.94S hexagonal nanoplates; a multi-gram scale product could be obtained in a single step. Under the synthetic scheme developed, the width of Cu1.94S nanoplates with a thickness of ~ 10 nm could be easily tuned from 70 nm to 130 nm. Their optical properties were investigated and their photothermal effect was also studied by photothermal optical coherence reflectometry (PT OCR). Cu1.94S hexagonal nanoplates showed a considerable photothermal effect, which was found to depend on the nanoparticle concentration. [ABSTRACT FROM AUTHOR]

CuS nano/microstructures with different morphologies, such as solid microspheres with blocks (1-CuS), nanospheres (2-CuS) and microspheres of nanoflakes (3-CuS), were synthesized using alanine based coordinating ligands (1–3) as structure controlling agents in hydrothermal synthesis. Interestingly, copper coordination polymers (4 and 5) that were prepared using the same ligand (2) but differed subtly in the coordination and water molecule presence produced distinctly different nano/microstructures. Hydrogen-bonded network polymer 4 gave CuS microspheres composed of nanocrystals (4-CuS) whereas coordination network polymer without water molecules 5 yielded nanocrystalline powdered materials (5-CuS). Importantly, the synthesised CuS nano/microcrystals exhibited dye degradation (methylene blue (MB), methyl orange (MO) and Rhodamine blue (RB)) at room temperature without using any specific light source. The CuS nano/microcrystals also showed morphology dependent dye degradation properties. The most efficient dye degradation was observed for nanosphere 2-CuS whereas 1-CuS and 4-CuS exhibited comparatively slow dye degradation. Thus, the present work demonstrates the utility of simple coordinating ligands and subtle changes in the coordination network for tuning CuS morphologies which showed morphology dependent dye degradation. [ABSTRACT FROM AUTHOR]

In this work, the preparation of copper sulfide (CuxS) thin films via microreactor-assisted solution deposition (MASD), consisting of separation of the homogeneous reaction and deposition from the molecular level heterogeneous surface reaction, is demonstrated. A particle-free flux in solution was obtained by adjusting the key process parameters, namely concentration of reactants, reaction temperature, and residence time, resulting in a high-quality film and a high deposition rate (40–100 times higher than that of films deposited by chemical bath deposition). Moreover, the growth of CuxS thin films was monitored using an in situ quartz crystal microbalance. We found that the growth rate significantly depends on the heterogeneous temperature and residence time, while limited influence of homogeneous temperature was observed. Furthermore, conformal and dense CuxS thin films were deposited on a highly textured Si surface that demonstrates enhanced photon absorption. [ABSTRACT FROM AUTHOR]

Copper sulphide is a material with low toxicity and high application potential. Colloidal synthesis allows its incorporation into hybrid nanostructures, which not only combine the properties of different materials within one nanocrystal, but also exhibit new features due to the interaction of the building blocks connected on the nanometer scale. Starting with copper sulphide seeds, such hybrid nanocrystals composed of copper sulphide and semiconductors like CuInS2, CuInxGa1-xS2, Cu2ZnSnS4, ZnS, CdS, and PbS have been synthesized. In some of these reactions themain focus lies on the formation of new hybrid nanocrystals; in others copper sulphide plays the role of a catalyst, and copper sulphide containing hybrid nanoparticles are only intermediates in the synthesis and shape control of other semiconductor materials. Both possibilities and the underlying growth mechanisms are discussed in this article. [ABSTRACT FROM AUTHOR]

A facile ligand exchange operation is found to be effective for the assembly and disassembly of MxS (M = Cu, Ag) nanocrystals in solution. The Cu1.94S nanoplates are taken as an example for tuning the physical properties of the nanocrystal colloid through reversible self-assembly. By establishing and disintegrating self-assembly of the Cu1.94S nanoplates, the localized surface plasmon resonance wavelength of the colloid can be switched between 1600 nm and 1850 nm, while the optical band gap can be tuned between 1.6 eV and 2.1 eV. The reported result is of significance for the potential applications of nanocrystals in fields such as photovoltaics and photodetection. [ABSTRACT FROM AUTHOR]

Well controlled nanosheets-based hierarchical microspheres (NSHMS) of pure covellite phase CuS were synthesized using a facile PVP assisted solvothermal process. The reaction conditions were optimized using various amounts of PVP to develop unique hierarchical structured hollow microspheres. CuS hollow structures have a bandgap of ~1.97 eV. These mesoporous structures exhibit excellent photocatalytic activity in degradation of organic dyes (Methylene Blue) under natural light in comparison to other structures of copper sulphide. These photocatalysts show extraordinary reusability with over 96.5% degradation of organic dye after 6th cycle. A "bottom-up" assembly was successfully developed to synthesize hollow microspheres with unique and well defined architectures at large scale, which offer a good opportunity to understand the fundamental significance of unusual and complex hierarchical structures for their potential applications. [ABSTRACT FROM AUTHOR]

Hierarchically structured hollow microspheres composed of copper sulfide (CuS) nanoplatelets have been successfully fabricated via a one-pot and green sonochemical process for the first time, using copper acetate and thiourea aqueous solution as precursors without surfactant or template. Large-scaled hollow architectures with outer diameters in the range of 1-1.2 μm are assembled by pure hexagonal single crystalline CuS nanoplatelets, being of about 20 nm in thickness with stacking faults in the crystal lattice. The UV-Vis diffuse reflectance spectra (DRS) analysis suggests that the band gap energy of the as-obtained CuS sample was estimated to be 1.27 eV, showing a significant red-shift compared with the bulk value. Hollow CuS structures possess the high surface area and double pore size distributions as measured from the N2 adsorption isotherms. Moreover, the possible growth mechanism for CuS hollow spheres is proposed on the basis of the temporal evolution controlled experiments. More importantly, this hierarchically structured CuS catalyst show highly efficient Fenton-like catalytic activity in degrading highly concentrated dyecontaining solution (50 mg . mL-1) with the help of hydrogen peroxide (H2O2), suggesting a promising application in wastewater purification. [ABSTRACT FROM AUTHOR]

Novel flower-like Cu2S structures with strong photoluminescence emission in the near-infrared region have been synthesized viaa simple, low-cost, and environmentally friendly chemical reaction from an oleic acid solution containing Cu(NO3)2·3H2O and S. Field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) reveal the flower-like nanostructures are monodispersed in large quantities. The formation of the flower-like structures can be tuned by adjusting the molar ratio of the two reaction reagents, concentration of precursors, reaction temperature, or reaction time. The possible growth mechanism of the formation of flower-like Cu2S structures was proposed. [ABSTRACT FROM AUTHOR]

CuS nanosheet thin films with large areas were synthesized in situon copper substrates through a facile, one-step treatment of copper foil and sulfur powder in the presence of N,N-dimethylformamide (DMF) at low temperature (60 °C or less). Compared with the previous reported solvothermal approach, the current low temperature route is simpler, low cost and low energy consumption. The effects of the reaction temperature on the synthesis and the optical property of CuS nanosheet films were investigated. The resulting CuS nanosheet films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and UV–vis spectrometer. In this study, we also demonstrated this method to prepare copper sulfide nanosheet films on ground-glass and indium tin oxide glass (ITO) substrates. We found that perfect nanosheet crystals could be obtained in all cases. The growth mechanism of CuS nanosheet-based films was proposed. The current method may open up a new way to prepare thin films of metal sulfide at low temperatures. [ABSTRACT FROM AUTHOR]

Novel polyhedral 26-facet CuS microcages decorated with amazingly unique crystalline structures as building blocks were successfully synthesized viaa facile sacrificial Cu2O templates solution route. Each of the polyhedral 26-facet CuS microcages has a composition of three pairs of square mesostructural shells, four pairs of nanotwinned triangular shells, and six pairs of rectangular single crystalline shells. Structural and morphological evolutions were investigated by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. The selective synthesis of the three different types of building blocks can be attributed to the intrinsic difference of the crystallographic structures of {110}, {100} and {111} facets of Cu2O crystals, which is of great significance in the “bottom-up” assembly of unusual hollow ordering superstructures. [ABSTRACT FROM AUTHOR]

We demonstrated a new strategy for the preparation of the cubic phase Cu1.8S rattle-type structure viaa dynamic isomers engaged solution route. The isomerization of thiourea into ammonium thiocyanate under solvothermal condition results in the formation of Cu1.8S and CuSCN in initial products. The transformation of CuSCN into Cu1.8S causes detachment between the core and shell. Studies show that the homogeneity and size of the rattle-type structure can be controlled by varying the concentration of precursor and PVP. These novel Cu1.8S rattle-type structures exhibit photoconductivity and may have potential applications in semiconductor optoelectronic devices. [ABSTRACT FROM AUTHOR]

Porous flowerlike Cu2S microspheres were synthesized through a solvothermal method employing CuCl and thiourea as Cu and S sources, respectively, and PVP as a surfactant. The as-prepared products have regular spherical shapes and uniform sizes around 1.8 µm, which are composed of 30–50 nm thick nanosheets with a lot of pores less than 5 nm. Time-dependent experiments showed that there were three main stages in the formation procedure. During morphology evolution, initial irregular aggregations could be transformed to long rods and then transformed further to final microspheres. A possible growth mechanism based on Ostwald ripening was proposed. The photovoltaic property test has also been conducted and these Cu2S microspheres have a higher photocurrent density than that of Cu2S nanoparticles. [ABSTRACT FROM AUTHOR]

Polygonal rings and microwires of covellite-type CuS were grown on micropillar arrays using chemical bath deposition and characterized by SEM, TEM, and XRD. A growth mechanism involving heterogeneous nucleation of CuS spheres at the micropillar tips, followed by their self-assembly into wires, is proposed. [ABSTRACT FROM AUTHOR]

This manuscript describes the selective modification of ZnO multipods with a series of wide bandgap and narrow bandgap semiconductors (ZnS, ZnSe, Bi2S3, and Cu2S). ZnO multipods are firstly synthesized viathe aqueous phase reaction of Zn2+ions with KOH at a temperature lower than 70 °C, which is simple, facile and free of organic capping agents. Through the reaction of the chalcogen source (Na2S2O3or Na2SeSO3) with the multipods supported by zinc or copper sheet, heterostructured ZnO/ZnS, ZnO/ZnSe, ZnO/Bi2S3and ZnO/Cu2S multipods are formed. The particles of ZnS and ZnSe are selectively deposited on the tips of the multipods but Cu2S and Bi2S3are randomly distributed on the entire surfaces of the multipods. The difference among the deposition sites of ZnS, ZnSe, Cu2S, and Bi2S3is related to the different structural affinity of these semiconductors to ZnO multipods. The heterostructures have integrated the optical absorption properties of ZnO multipods and the deposited semiconductors, and as a result, the optical absorption range of ZnO multipods is expanded (335∼1000 nm). The photoelectrochemical properties of the heterostructures are also different from that of bare ZnO multipods. The photocurrent densities yielded by bare ZnO multipods, heterostructured ZnO/ZnS, ZnO/ZnSe, and ZnO/Bi2S3multipods are 0.08 mA cm−2, 0.10 mA cm−2, 0.30 mA cm−2, and 0.03 mA cm−2, respectively. As for ZnO/Cu2S multipods, the photocurrent is unexpectedly smaller than the dark current. [ABSTRACT FROM AUTHOR]

Ball-flower shaped CuS structures have been synthesized by using mixed copper chloride and thiourea in a simple hydrothermal process employing poly(vinylpyrrolidone) (PVP) as the surfactant. The morphological investigations by field emission scanning electron microscope (FE-SEM) reveal that the ball-flower shaped nanostructures are monodispersed in large quantities. The ball-flower shaped morphologies are strongly dependent on the different ratios of copper chloride to thiourea, the reaction temperature and reaction time. The possible growth mechanism of the formation of ball-flower shaped CuS products is discussed in detail. In addition, the photocatalytic activity of ball-flower shaped CuS architectures has been tested by the degradation of rhodamine B (RhB) under UV light irradiation, showing that the as-prepared ball-flower shaped CuS structures exhibit high photocatalytic activity for the degradation of RhB. [ABSTRACT FROM AUTHOR]