Hierarchical CuS Research Articles

Superior performance of hierarchical 3D microflower CuS grown on carbon cloth as binder free electrode for supercapacitor applications

Copper sulfide (CuS) was grown on the carbon cloth (CC) utilizing the traditional hydrothermal method. The role of different reaction time of 5 h, 10 h, and 15 h (C15) were investigated with fixed reaction time of 150 °C. XRD confirmed the growth of pure CuS on CC. Macroscopic changes in morphology were observed with increasing the reaction time and C15 showed ∼3.08 μm diameter of CuS microflowers with ∼ 34.68 nm thickness of nanosheets embedded in the microflowers. C15 showed a lowest bandgap of 1.8 eV with high copper content of 34 % and the copper content increases fast electron movement and maintains structural stability. The supercapacitor behavior was investigated in 1 M Mg(NO3)2 aqueous electrolyte and C15 demonstrated the highest specific capacitance of 83.70 F/g at 5 mV/s. An aqueous symmetric electrode made with C15 displays 149 F/g specific capacitance and 87.2 % retention at 1 A/g for 1000 cycles.

High-performance asymmetric supercapacitor based on hierarchical hydrothermally grown CuS nanostructures

In this work, various hierarchical CuS were fabricated via an efficient one-step hydrothermal process with different surfactants (polyvinyl pyrrolidine (CS-P), Citric acid (CS-C), Oleic acid (CS-O)) and examined as electrode materials for supercapacitors. XRD, FESEM, HRTEM and BET analysis reveal the fabrication of a hexagonal crystal structure with porous microspheres of CuS-PVP having a BJH pore diameter of 16.241 nm. Among these, the CS-P electrode exhibits a superior specific capacitance of 414.28F/g at 1 A/g of current density in the KOH electrolyte. Additionally, an asymmetric supercapacitor built with CS-P as positive and Activated carbon as negative electrodes exhibited a specific energy of 27.95 Wh/kg at 624.96 W/kg of specific power at 2 A/g and demonstrated outstanding cycling stability with 80.6 % persistence of capacitance for 2500 GCD cycles at 10 A/g. Additionally, an ASC device created for use in real life and tested by charging it for 30 s managed to reach a 3-minute 50-second self-discharging duration. Hence, these favourable electrochemical findings indicate that the hydrothermally grown hierarchical CuS-PVP electrode is a bright potential material in energy storage applications.

Constructing hierarchical CuS hollow spheres as efficient anode for aqueous zinc-ion batteries

In recent years, aqueous zinc-ion batteries (ZIBs) have emerged as a prominent research topic due to their inherent safety attributes, relatively low cost, and comparatively higher energy density. However, the challenges associated with the zinc metal anode in the form of dendrite formation, hydrogen evolution, and severe side reactions have proven to be particularly vexing. Thus, it is imperative to investigate novel intercalation-type anode materials for ZIBs that exhibit exceptional structural properties and appropriate redox potentials based on conversion mechanisms. In this work, through adding polyvinylpyrrolidone (PVP) surfactant to precursors and tailoring reaction time, hierarchical CuS hollow spheres are successfully constructed by a facile one-step hydrothermal process. When applied as an anode in ZIBs, the hollow hierarchical CuS with large surface area can effectively reduce the transport distance of electrons and Zn2+ and alleviate volume expansion during the insertion/extraction of Zn2+. The hierarchical CuS hollow spheres prepared over 8 h (CuS-8) exhibit a specific capacity of 126 mAh/g and long-term cycle life (1500 cycles) at a current density of 3 A/g. In addition, CuS-8//MnO2@CNTs full-cell shows a capacity retention of 117 mAh/g after 300 cycles at 1 A/g current density, which proves the advantage of hierarchical CuS hollow spheres in serving as an efficient and durable anode material for ZIBs.

Fatty Amine-Mediated Synthesis of Hierarchical Copper Sulfide Nanoflowers for Efficient NIR-II Photothermal Conversion and Antibacterial Performance.

Non-noble metal photothermal materials have recently attracted increasing attention as unique alternatives to noble metal-based ones due to advantages like earth abundance, cost-effectiveness, and large-scale application capability. In this study, hierarchical copper sulfide (CuS) nanostructures with tunable flower-like morphologies and dimensional sizes are prepared via a fatty amine-mediated one-pot polyol synthesis. In particular, the addition of fatty amines induces a significant decrease in the overall particle size and lamellar thickness, and their morphologies and sizes could be tuned using different types of fatty amines. The dense stacking of nanosheets with limited sizes in the form of such a unique hierarchical architecture facilitates the interactions of the electromagnetic fields between adjacent nanoplates and enables the creation of abundant hot-spot regions, thus, benefiting the enhanced second near-infrared (NIR-II) light absorptions. The optimized CuS nanoflowers exhibit a photothermal conversion efficiency of 37.6%, realizing a temperature increase of nearly 50 °C within 10 min under 1064 nm laser irradiations at a power density of 1 W cm-2. They also exhibit broad-spectrum antibacterial activity, rendering them promising candidates for combating a spectrum of bacterial infections. The present study offers a feasible strategy to generate nanosheet-based hierarchical CuS nanostructures and validates their promising use in photothermal conversion, which could find important use in NIR-II photothermal therapy.

CuS–CdS@TiO2 multi-heterostructure-based photoelectrode for highly efficient photoelectrochemical water splitting

A three-dimensional hierarchical CuS–CdS@TiO2 multi-heterostructure has been fabricated as a highly promising photoanode for PEC water splitting. The CdS@TiO2 structure was synthesized by a two-step hydrothermal method, therein TiO2 nanorods (TiO2 NRs) were used as the template to grow the CdS branches (CdS BRs). Then the surface of the heterostructure was sequentially coated with a p-type CuS semiconductor via a simple SILAR method. The optimized CuS–CdS@TiO2 photoelectrode exhibits a remarkably high photocurrent density of 12.6 mA cm−2 at 1.23 V vs RHE under standard AM 1.5 light illumination. The enhancement in the PEC performance could attribute to the wide range of solar spectrum absorption in CdS BRs, which can generate more photo charge carriers. Meanwhile, the high conductivity of TiO2 NRs serves as an efficient pathway to transfer photogenerated electrons from the CdS BRs to the FTO substrate. In addition, the p-n junction formed between CuS and CdS@TiO2 heterostructure could improve the separation of electron-hole on the surface of the photoanode. This study demonstrates an efficient pathway to improve the photoelectrochemical performance of TiO2-based photoanodes.

Engineering multifunctional carbon black interface over Mn0.5Cd0.5S nanoparticles/CuS nanotubes heterojunction for boosting photocatalytic hydrogen generation activity

Developing exceptionally robust and cost-effective cocatalysts to suppress charge recombination and reduce the reaction energy barrier remains an enormous challenge for producing high-valued and storable hydrogen fuel from photocatalytic water splitting. Herein, novel Mn0.5Cd0.5S nanoparticles modified with multifunctional carbon black (CB) nanowires and CuS nanotubes as dual cocatalysts were fabricated via sonochemical loading, and subsequent in-situ deposition routes. In this ternary hierarchical architecture, both CB nanowires and CuS nanotubes can serve as normal electron cocatalysts to markedly promote the hydrogen generation performance by lowering the thermodynamic overpotential for hydrogen evolution. Moreover, due to the high electrical conductivity, the multifunctional CB material can also function as a bridge to effectively capture and transmit the photoexcited electrons from Mn0.5Cd0.5S to CuS with outstanding electrocatalytic hydrogen evolution activity, thus maximizing the carrier separation and H2-evolution reaction kinetics. Interestingly, the cooperative effects between CB and CuS dual cocatalysts are also helpful for improving the oxidation capacity of photoexcited holes by lowering the valence band position of Mn0.5Cd0.5S, which further accelerates the electron-hole separation. As a result, the constructed Mn0.5Cd0.5S/CB/CuS hierarchical multiheterojunction catalyst shows the superior hydrogen generation efficiency of 819.9 μmol h−1 and excellent stability under simulated solar light irradiation.

A 3D Opened Hollow Photothermal Evaporator for Highly Efficient Solar Steam Generation

Herein, using hierarchical porous CuS–cellulose composite as photothermal materials, a 3D opened hollow photothermal evaporator is designed and fabricated to target high solar evaporation rates. Such a unique structure not only imparts the solar evaporator with an efficient water evaporation by minimizing energy loss, introducing cold evaporation surfaces for drawing additional energy from the bulk water and surrounding air, but also fully activates evaporation on both inner and outer evaporation surfaces, thus delivering superior evaporation rates compared to the enclosed evaporators. Moreover, under convective flow, this special structure effectively promotes the escape of vapor inside the evaporator to avoid the vapor accumulation, further enhancing the evaporation on inner evaporation surfaces, thus improving the evaporation rate up to11.911 kg m−2 h−1 under a convective flow rate of 4.0 m s−1 and 1.0 sun irradiation. The operability of the as‐prepared solar evaporator under natural environmental conditions is examined by outdoor evaporation tests. The obtained solar evaporator is demonstrated to be applicable for generating clean water from model seawater and dye wastewater. An impetus for promoting practical application of solar steam generation in seawater desalination and wastewater purification is provided.

Purposely synthesis of hierarchical CuS nanoflowers composed of ultrathin nanoflakes with exposed (0 0 1) facets using a solvent-template ionic liquid and their application in supercapacitors

Two hierarchical CuS nanostructures assembled by nanoflakes with exposed (001) facets are purposely synthesized using ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) as solvent-template. [Bmim]Cl can act as efficient template for the formation of flake-like building blocks by adsorbing on the (001) facet of CuS. More importantly, the viscosity of [Bmim]Cl can be altered by changing the temperature; thereby, the self-assemble process of the building blocks can be controlled and accordingly the shapes of the products are “tailored”. The structural properties of the as-formed compact CuS nanoflowers (C-CuS) and loose CuS nanoflowers (L-CuS) are tested by XRD, SEM, TEM, HRTEM, and XPS, and the growth mechanisms are discussed in depth. When used as the electrode materials for supercapacitors, C-CuS exhibit higher specific capacitance and better rate capability than L-CuS. The improved capacitive performance of C-CuS may be due to the structural synergistic effect of ultrathin building units and dense hierarchical nanostructure.

Hierarchical nanosheet-assembled copper sulfide microspheres as the cathode materials for rechargeable magnesium batteries

Rechargeable magnesium battery is an inexpensive, high-safety energy storage technology suitable for large-scale applications. However, its development is still hindered by lacking high-performance cathode materials. Herein, we present a simple one-step template-free hydrothermal method to synthesize hierarchical CuS microspheres self-assembled from nanosheets as the cathode materials for rechargeable magnesium battery. Owing to the special structure configuration, the as-synthesized CuS microspheres can exhibit a high specific capacity of 252 mAh g–1 at 100 mA g–1, and a reversible specific capacity of 171.2 mAh g–1 at 500 mA g–1. Additionally, the CuS microspheres also show good rate capability with 91.7 mAh g–1 specific capacity at high current density of 1000 mA g–1 and a long-term cycling stability over 500 cycles. These electrochemical results indicate that the fabrication of the CuS microspheres with hierarchical structure can provide an efficient route to develop high-performance copper sulfide cathode materials for emerging rechargeable magnesium batteries.

Synthesis of flower and biconcave shape CuS: Enhancement of super-capacitance properties via Ni–CuS nanocomposite formation

Copper sulphide nanocrystals (NCs) and their derivatives are rapidly gaining attention of researchers due to wide variety of exciting physical properties. These properties can be further tuned by varying morphology and incorporation of suitable elements. Here, we report a simple and facile method for the synthesis of hierarchical flower shape CuS containing 30–40 nm thick nanosheets and Ni–CuS nanocomposite with varying molar ratio of Ni to CuS. It is observed that the formation of hierarchical flower shape of CuS is significantly depend on the type of sulfur source and metal to sulfur precursor ratio. The incorporation of uniformly decorated nickel particles on CuS micro flowers increased electrochemically active sites leading to better ion diffusion kinetics. Further, the specific capacitance value of Ni–CuS (molar ratio of 0.6:1) reflected significant enhancement, more than three times (464.03 F/g at 2 A/g), than the pure CuS (132.89 F/g at 2 A/g) submicron flowers with excellent cyclic stability.

Surface-enhanced Raman scattering by hierarchical CuS microflowers: Charge transfer and electromagnetic enhancement

The research of surface enhanced Raman scattering (SERS) based on semiconductor substrate expends the application field of SERS technology. However, the relatively low enhancement sensitivity of semiconductor materials is still a problem to be solved urgently. Herein, high-performance enhancement of Raman scattering is achieved through hierarchical CuS microflowers. Simultaneously based on electromagnetic near-filed effect and charge transfer effect between the reporter molecule and CuS material system, the enhancement factor can reach 105 and the detection limitation is as low as 10−8 M for MG and 10−7 M for CV and R6G molecules. The enhancement sensitivity is proved to be related to the number and spacing of petals of the CuS flowers, and illumination of the incident wavelength. A finite integration method is conducted to estimate the electromagnetic field around the CuS microflower system. The ground-state properties of the system are calculated by DFT method. The energy level schematic diagram of the probe molecules on CuS system is employed to investigate the charge transfer process between the reporter molecule and CuS microflower system. Due to the unique properties of semiconductors, such as surface functionalization, stable material properties and degradability, CuS microflower can be served as a high-performance SERS platform to expend the application field of SERS, and is a valuable tool for the research of semiconductor surfaces.

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

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

Hierarchical CuS doped with vanadium nanosheets with micro skein overall morphology as a high performance amperometric glucose sensor

In this paper, an easy one-step hydrothermal method was reported to preparation of unique hierarchical porous CuS doped with vanadium (V-CuS) nanosheets with micro skein overall morphology. The fabricated V-CuS micro skein was casted on the surface of glassy carbon (GC) electrode and was used as an efficient electrocatalyst for glucose in alkaline solutions. As a amperometric glucose sensor, this proposed sensor offers a high sensitivity of 1800 μA mM−1 cm−2, with a wide linear range from of 2 μM to 5 mM, and a low detection limit of 0.4 µM (S/N = 3). The non-enzymatic V-CuS/GC electrode-based sensor showed acceptable selectivity and satisfactory stability. Moreover, the designed sensor showed accurate results for the determination of glucose in blood serum samples.

One-pot preparation of robust, ultraviolet-proof superhydrophobic cotton fabrics for self-cleaning and oil/water separation

Robust superhydrophobic cotton fabrics with ultraviolet (UV)-proof performance were prepared via a simple one-pot method with composite coating of hierarchical CuS microflower nanoparticles and silicone elastomer polydimethylsiloxane (PDMS). The facile preparation of CuS microflower nanoparticles was conducted via relatively low-temperature reaction. The surface morphology, chemical composition, thermal degradation behavior, and crystal structure of the products were evaluated. The simultaneous roughening due to hierarchical rough morphology of CuS microflower nanoparticles and PDMS hydrophobization resulted in the coated fabric with microscale fibers exhibiting superhydrophobic property and its water contact angle was 159.3° ± 0.6°. The superhydrophobic textile also displayed outstanding UV-proof performance with a large ultraviolet protection factor of 535.36 due to ultraviolet-absorption, light scattering and frequent light reflection of hierarchical CuS nanoparticles. The superhydrophobic textile showed excellent stain resistance and self-cleaning property and also was able to separate oil and water with high efficiency and good separation reusability caused by the contrasting wettability of the coated textile for water droplets and oil droplets. The as-prepared superhydrophobic fabric displayed excellent robustness against 2000 cycles rubbing, water jetting and long-time UV illumination and satisfactory chemical stability. This superhydrophobic coating showed no negative impact on the mechanical strength of cotton fabric. The facile approach in favor of large-scale preparation showed promising potential for wide application of flexible superhydrophobic cotton textiles with ultraviolet-blocking performance.

Facile synthesis of hierarchical CuS microspheres with high visible-light-driven photocatalytic activity

To date, a large volume of research has focused on the synthesis of microsphere photocatalysts with a hierarchical structure due to their high recovery efficiency and large specific surface area resulting in high photocatalytic activity. Nonetheless, the development of a facile approach to designing and controlling the morphology of microspheres has remained a challenge. In this study, well-controlled hierarchical CuS microspheres were synthesized via the simple chemical transformation of CuO templates prepared by an ultrasonic spray pyrolysis process which is an efficient form of solution aerosol thermolysis. The transformation rate was controlled by the ratio of CuO template and sulfur precursor, which enabled the implementation of a clear hierarchical structure. Time-series sulfurization experiments indicate that how the hierarchical shape evolved. The hierarchical CuS microsphere synthesized under optimal synthetic conditions shows excellent photocatalytic activity, Rhodamine B, methylene blue and methyl orange dye molecules were readily decomposed by the CuS microsphere, each having photocatalytic performance of 11.1, 8.3 and 32.0 times greater than commercial TiO2 nanoparticles. Furthermore, the degradation rate after fiver cycles is still above 95 %, indicating that the CuS microsphere was not deactivated and that stability and reusability were excellent.

Synthesis of 3D hierarchical CuS architectures consisting of 1D nanotubes for efficient photocatalysts

3D hierarchical CuS architectures consisting of 1D nanotubes have been synthesized by the combination of the self-assembly method and a simple solvothermal process. The hierarchical structures not only provide a large number of active sites on the surfaces, but also integrate the advantages of 1D nanotubes for molecular or ionic transport and 3D for mechanical stability. The hierarchical CuS architectures can be a Fenton-like catalyst with excellent catalytic performance. The degradation rate constant k of 3D hierarchical CuS is 8.37 × 10−2 min−1 at the concentration of rhodamine B (RhB) of 50 mg/mL under visible light irradiation.

Hierarchical Copper Sulfide Porous Nanocages for Rechargeable Multivalent-Ion Batteries.

Copper sulfide (CuS) has been identified as a promising positive electrode material for some multivalent-ion batteries (such as the magnesium-ion battery) because of its high theoretical capacity, environmental friendliness, and wide availability. However, the clumsy multivalent-ion with high polarity inclines toward sluggish ion insertion/de-insertion, leading to inadequate electrochemical performance. In this work, the hierarchical CuS porous nanocages are successfully fabricated via a facile one-step room-temperature liquid-phase process and evaluated as positive electrode materials for rechargeable magnesium batteries. Owing to the structural advantages, a high reversible magnesium storage capacity of 228 mA h g-1 is attained, which is superior to the previously reported results under similar conditions. Besides, the application of CuS as positive electrode materials for calcium-ion, zinc-ion, iron-ion, and aluminum-ion batteries is investigated. The hierarchical CuS porous nanocages display promising electrochemical performance in those multivalent-ion battery systems. Our work proves the superiority of the nanostructure design in improving the electrochemical performance of positive electrode materials for multivalent-ion batteries.

3D hierarchical CuS microflowers constructed on copper powders-filled nickel foam as advanced binder-free electrodes

A novel strategy, consisting of sonication-assisted filling step followed by a chemical-bath surface sulfidization process, was designed to fabricate 3D hierarchical CuS microflowers constructed on copper powders-filled nickel foam (Cu@CuS–NF) as advanced binder-free electrodes for high-performance supercapacitors. Scanning electron microscope, powder X-ray diffraction and X-ray photoelectron spectroscopy techniques were employed to confirm the microstructure and composition. Electrochemical measurements demonstrated that the Cu@CuS–NF electrode has highly improved capacitance with an ultra-high area capacitance of 11.4 F cm−2 at a high current density of 90 mA cm−2. Also, the Cu@CuS–NF electrode has superior cycling stability with more than 100% retention of the initial area capacitance after 3000 cycles at 180 mA cm−2. The excellent electrochemical performance can be mostly attributed to a combination of the ultra-large loading area and very good electroconductive network formed from copper powders filling inside nickel foam. Our work opens a new door to engineering ultra-high-performance nickel-foam-based electrodes for electrochemical devices including water splitting and energy storage/conversion.

Synthesis of microflower-like vacancy defective copper sulfide/reduced graphene oxide composites for highly efficient lithium-ion batteries

Copper sulfide (CuS) is considered a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity and good electrical conductivity. However, the inferior cycle performance and low coulombic efficiency of CuS caused by structure detoriation and degradation and the ‘shuttling effect’ of polysulfide intermediates are restricting its practical application. In this work, we report a facile method to generate S vacancies (Vs) in CuS nanoflowers by thermal annealing in Ar. The obtained CuS was composited with reduced graphene oxide (rGO) to prepare an anode for LIBs. The existence of vacancy defects in CuS leads to electron delocalization and excitation, which is responsible for the conductivity improvement and fast charge transport kinetics. Meanwhile, the graphene coating layer ensures fast pathways for Li+ ion diffusion and provides strong physical adsorption of the polysulfides. Furthermore, hierarchical CuS spheres composed of ultrathin nanosheets provide large void spaces to accommodate the volume expansion of CuS. The synthesized composite exhibited a high initial discharge capacity of 882 mAh g−1 and demonstrated stable cyclability along with around 99% coulombic efficiency over 100 cycles. The results of this work reveal that Vs-CuS/rGO composites are promising anodes to enhance the performance of next-generation lithium-ion batteries.

Enhanced performance of hierarchical CuS clusters applying TRGO as conductive carrier for supercapacitors

A facile hydrothermal-assisted process without surfactant was developed to prepare hierarchical CuS clusters and novel CuS–thermal reduced graphene oxide (TRGO) composites as advanced electrodes. The preparation of TRGO was simple and efficient without protective atmosphere and reagent, and the CuS–TRGO composites were characterized by distributed CuS microspheres coated with TRGO carrier uniformly to improve the pseudocapacitance properties. Electrochemical performance of the electrode of CuS–TRGO composites was elucidated by utilizing cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy methods respectively. The electrode exhibited ultrahigh specific capacitance up to 1222.5 F g−1 at 1 A g−1, good rate capability as well as excellent cycling stability with 92.11% capacitance retention after 3000 charge–discharge cycles at 5 A g−1, which implied that the as-prepared CuS–TRGO could be a favorable and suitable electrode material as supercapacitors in energy storage.