Cu2S Nanowires Research Articles

Growth of CuS nanowire on copper mesh for efficient solar-driven water evaporation and wastewater purification

This study proposed a multifunctional material, CuS nanowire, grown on a copper mesh (CM), for application in wastewater purification. CuS/CM could rapidly evaporate and collect water under solar irradiation. CuS nanowires were successfully synthesized on CM through a liquid–solid reaction at room temperature, followed by sulfidation. Water evaporation experiments conducted using meshes suspended in water to determine the most efficient configuration revealed that CuS/CM was the most efficient material. Owing to the localized surface plasmon resonance induced by oxygen vacancies, CuS/CM exhibited a high water evaporation rate (4.0523 kg·m-2h−1 @ 3 sun) and energy conversion efficiency (96.1 %) in Structure A with a vertical length of 4 cm under 3 sun irradiation. To evaluate its effectiveness in wastewater treatment, CuS/CM was used to evaporate and collect methylene blue (MB)-contaminated water at rates of 1.5747 and 0.8624 kg·m-2h−1. Furthermore, CuS/CM demonstrated photocatalytic activity during MB degradation. Under xenon lamp illumination for 6 h, CuS/CM exhibited a 73 % degradation efficiency for MB, indicating its photocatalytic properties. CuS/CM effectively purify dyeing wastewater due to their fast water evaporation rate and the photocatalytic capability of CuS, making them promising for wastewater treatment and desalination applications.

Multi-scale CuS-rGO pyramidal photothermal structure for highly efficient solar-driven water evaporation and thermoelectric power generation

Integrated water evaporation and thermoelectric power generation system (IWETPGS) has been recognized to be a promising strategy for the utilization of solar energy. Herein, we developed a new type of IWETPGS with multi-scale pyramidal photothermal structures. They featured three-dimensional pyramidal structures with microscale gradient porous copper foams, as well as micro/nanoscale CuS nanowires and reduced graphene oxide (rGO) composite materials. They combined the merits of efficient multiple refraction and absorption of light, broad-spectrum absorption capabilities of rGO and high near-infrared extinction coefficient of CuS, as well as fast water transportation by gradient porous matrix. These photothermal structures induced a photothermal conversion efficiency of 97.6%. An IWETPGS integrating these structures with a thermoelectric generator (TEG) and microchannel heat sink was developed, and outstanding evaporation and output power performance were obtained simultaneously with an evaporation rate of 2.29 kg/m2h and maximum output power of 1.32 W/m2 under 1 sun illumination. Outdoor tests showed that an average daily water production of 12.1 kg/m2 and a maximum power generation of 5.55 W/m2 was obtained. This work provides a high-performance multi-scale CuS-rGO pyramidal photothermal structure to achieve freshwater and thermoelectric power co-generation, which provides potential opportunities for freshwater and electricity supply in remote areas.

Self-supported, additive-, and binder-free CuS nanowire array for high performing Na-ion capacitor

Na-ion capacitors are considered to be one of the most promising energy storage devices due to its low cost, safe, highly abundance in nature and comparable performance to lithium-ion capacitor. NICs provide high power density as well as good energy density in a single device. However, the lack of host materials to store Na-ions has challenged its commercialization. It is very important to investigate a suitable host material for the Na-ion capacitors. Metal chalcogenides shows significant electrochemical performance towards the NICs. The low capacitance value, stability in the electrolyte is the main drawbacks of the metal chalcogenides. The tailoring in the nanostructures and the component of the electrode can improve the electrochemical performance of Na-ion capacitors. Herein, a liquid-solid chemical method is developed to fabricate self-supported, binder, and additive-free CuS nanowires on porous copper foam electrode, and investigated for the first time as an anode for Na-ion capacitor. Using Cu-foam instead of Cu-foil as a substrate and current collector enhances the 5-fold capacitance (380 F g−1 at 1 A g−1) for Na-ion capacitors, which suggest the replacement of the Cu-foil as current collector. The involved conversion reaction in CuS NWs/Cu-foam is confirmed by in-situ XRD measurement. Since it is observed that the CuS NWs/Cu-foam exhibited good electrochemical and redox features with superior specific capacitance in three-electrode system, a symmetric device is assembled. The symmetric device shows 400 F g−1 of specific capacitance at 1 A g−1 with 28 Wh kg−1 of energy density and 1440 W kg−1 of power density. It is favourable that CuS nanowires are still preserving to the same morphology after 1000 charge-discharge cycles, which is confirmed by the SEM imaging.

Simultaneous etching of underlying metal oxide and sulfide thin films during Cu2S atomic layer deposition

Herein, we report the simultaneous etching of selected metal oxide and sulfide underlayers during the atomic layer deposition (ALD) of Cu2S. The unexpected etch was observed to be prompted by the infiltration of highly mobile Cu+ ions from a top ALD Cu2S layer into underlying films, followed by fragmentation of the underlayers and subsequent outward diffusion of both cations and anions from the underlayers to the Cu2S surface. A strong correlation was observed between the susceptibility to etching, etch rates and the bond dissociation energies of the underlayers. ZnS, ZnO, SnS, and SnO thin films were etched at different rates, while SnO2 exhibited high resistance to etching. Interestingly, the etch process exhibited self-limiting characteristics dependent on the Cu precursor and H2S gas dose times, thus indicating simultaneous Cu2S ALD and controlled sublayer etching reactions. Based on the findings, we proposed a possible mechanism by which the etching proceeds. We further explored, the synthesis of 3-dimensional Cu2S/ZnO and Cu2S nanowires using ALD Cu2S and the observed ZnO etching phenomenon.

A Self‐Standing High‐Performance Hydrogen Evolution Electrode with Nanostructured NiCo2O4/CuS Heterostructures

An efficient self‐standing 3D hydrogen evolution cathode has been developed by coating nickel cobaltite (NiCo2O4)/CuS nanowire heterostructures on a carbon fiber paper (CFP). The obtained CFP/NiCo2O4/CuS electrode shows exceptional hydrogen evolution reaction (HER) performance and excellent durability in acidic conditions. Remarkably, as an integrated 3D hydrogen‐evolving cathode operating in acidic electrolytes, CFP/NiCo2O4/CuS maintains its activity more than 50 h and exhibits an onset overpotential of 31.1 mV, an exchange current density of 0.246 mA cm−2, and a Tafel slope of 41 mV dec−1. Compared to other non‐Pt electrocatalysts reported to date, CFP/NiCo2O4/CuS exhibits the highest HER activity and can be used in HER to produce H2 with nearly quantitative faradaic yield in acidic aqueous media with stable activity. Furthermore, by using CFP/NiCo2O4/CuS as a self‐standing electrode in a water electrolyzer, a current density of 18 mA cm−2 can be achieved at a voltage of 1.5 V which can be driven by a single‐cell battery. This strategy provides an effective, durable, and non‐Pt electrode for water splitting and hydrogen generation.

Copper(II)-Mediated Self-Assembly of Hairpin Peptides and Templated Synthesis of CuS Nanowires.

The self-assembly of peptides and proteins under well-controlled conditions underlies important nanostructuring processes that could be harnessed in practical applications. Herein, the synthesis of a new hairpin peptide containing four histidine residues is reported and the self-assembly process mediated by metal ions is explored. The work involves the combined use of circular dichroism, NMR spectroscopy, UV/Vis spectroscopy, AFM, and TEM to follow the structural and morphological details of the metal-coordination-mediated folding and self-assembly of the peptide. The results indicate that by forming a tetragonal coordination geometry with four histidine residues, copper(II) ions selectively trigger the peptide to fold and then self-assemble into nanofibrils. Furthermore, the copper(II)-bound nanofibrils template the synthesis of CuS nanowires, which display a near-infrared laser-induced thermal effect.

One-Pot Synthesis of Copper Sulfide Nanowires/Reduced Graphene Oxide Nanocomposites with Excellent Lithium-Storage Properties as Anode Materials for Lithium-Ion Batteries.

Copper sulfide nanowires/reduced graphene oxide (CuSNWs/rGO) nanocompsites are successfully synthesized via a facile one-pot and template-free solution method in a dimethyl sulfoxide (DMSO)-ethyl glycol (EG) mixed solvent. It is noteworthy that the precursor plays a crucial role in the formation of the nanocomposites structure. SEM, TEM, XRD, IR and Raman spectroscopy are used to investigate the morphological and structural evolution of CuSNWs/rGO nanocomposites. The as-fabricated CuSNWs/rGO nanocompsites show remarkably improved Li-storage performance, excellent cycling stability as well as high-rate capability compared with pristine CuS nanowires. It obtains a reversible capacity of 620 mAh g(-1) at 0.5C (1C = 560 mA g(-1)) after 100 cycles and 320 mAh g(-1) at a high current rate of 4C even after 430 cycles. The excellent lithium storage performance is ascribed to the synergistic effect between CuS nanowires and rGO nanosheets. The as-formed CuSNWs/rGO nanocomposites can effectively accommodate large volume changes, supply a 2D conducting network and trap the polysulfides generated during the conversion reaction of CuS.

Annealing effects on the physical and optical properties of Cu2S/CIGS core/shell nanowire arrays

The effects of annealing on the physical and optical properties of Cu2S/CuIn0.7Ga0.3Se2 (Cu2S/CIGS) core/shell nanowire arrays were studied. Cu2S nanowire arrays and CIGS shell layers were prepared by a solid–gas reaction and electrodeposition, respectively. The structure and light absorption properties of Cu2S/CIGS core/shell nanowire arrays were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and diffuse reflectance spectroscopy. The melting point of Cu2S nanowire arrays increased after the electrodeposition of CIGS. The crystallinity of the CIGS shell layer increased with increasing annealing temperature from 350 to 650 °C, and most of the amorphous area of the CIGS shell layer becomes twin crystals after thermal annealing. The Cu2S/CIGS core/shell structure collapsed when the annealing temperature increased to 800 °C. The light absorption properties of the Cu2S/CIGS core/shell structure were enhanced after thermal annealing, and the band gap corresponding to CIGS was also obtained. This study indicates that the annealing temperature should be controlled between 350 and 800 °C to convert this Cu2S/CIGS core/shell structure to a CuIn0.7Ga0.3(Se, S)2 (CIGSS) one-dimensional nanostructure. This research demonstrates the potential for preparing CIGSS one-dimensional nanostructures by thermal annealing.

Detection of human immunoglobulin G by label-free electrochemical immunoassay modified with ultralong CuS nanowires.

Ultralong copper sulfide nanowires (CuSNWs) were synthesized via a simple wet chemical route. Due to the desired surface charge characteristics and attractive electrocatalytic activity toward the oxidation of ascorbic acid, such ultralong one-dimensional nanomaterials provided an interesting platform for electrochemical signal amplification. By immobilizing an anti-IgG antibody on the chitosan (CS)-CuSNWs film, a novel label-free electrochemical immunosensor was thus developed for detection of human immunoglobulin G (IgG). Various experimental parameters were studied, and the interference effects from other proteins were checked. Under the optimum conditions, the decrease of the amperometric signal presented a linear relationship in the IgG concentration range of 0.001-320 ng mL-1 with a detection limit of 0.1 pg mL-1 (S/N = 3). The practical application of the fabricated immunosensor has also been demonstrated by detecting IgG in real human serum samples. The satisfactory results hint the significant potential in clinical analysis.

Synthesis and self-assembly of partially sulfonated poly(arylene ether sulfone)s and their role in the formation of Cu2S nanowires

Partially sulfonated poly(arylene ether sulfone)s was synthesized by one-step SNAr copolymerization and self-assembled into spherical micelles in aqueous solutions, which assisted formation of Cu2S nanowires on various substrates.

Growth of Hydrophilic CuS Nanowires via DNA‐Mediated Self‐Assembly Process and Their Use in Fabricating Smart Hybrid Films for Adjustable Chemical Release

Facile growth of CuS nanowires through self-assembly and their application as building blocks for near-infrared light-responsive functional films have been demonstrated. It is found that DNA is a key factor in preparing the CuS material with defined nanostructure. An exclusive oriented self-aggregate growth mechanism is proposed for the growth of the nanowires, which might have important implications for preparing advanced, sophisticated nanostructures based on DNA nanotechnology. By employing the hydrophilic CuS nanowire as an optical absorber and thermosensitive nanogel as guest reservoir inside alginate film, a new platform for the release of functional molecules has been set up. In vitro studies have shown that the hybrid film possesses excellent biocompatibility and the release rate of chemical molecules from the film could be controlled with high spatial and temporal precision. Our novel approach and the resulting outstanding combination of properties may advance both the fields of DNA nanotechnology and light-responsive devices.

Synthesis of copper sulfide nanowire bundles in a mixed solvent as a cathode material for lithium-ion batteries

Novel copper sulfide (CuS) nanowire bundles with a diameter of about 6 nm and a length up to several micrometers are successfully synthesized by a template- and surfactant-free method in a dimethyl sulfoxide (DMSO)-ethyl glycol (EG) mixed solvent. The resulting CuS nanowire bundles are used as a cathode material in lithium-ion batteries and exhibit a large capacity and excellent cycling stability and rate capability. The unique structure of the CuS nanowire bundles is responsible for their excellent electrochemical performance.

Photocurrent and photovoltaic characteristics of copper sulfide nanowires grown by a hydrothermal method

We synthesized p-type copper sulfide (CuS) nanowires by hydrothermal method using a polymer as structure directing agent. Single nanowire devices were then fabricated and hole concentration was measured to be ~4×1018cm−3. Schottky contacts between the nanowires and metal electrodes have been distinctively imaged by a scanning photocurrent microscopic method. As the synthesized CuS nanowires were much longer than the diffusion length, the nanowires were intentionally broken down to demonstrate a photovoltaic device utilizing the Schottky contact with Cu electrodes.

Pressure-induced phase transformations in mineral chalcocite, Cu2S, under hydrostatic conditions

High-pressure room-temperature angle-dispersive powder X-ray diffraction measurements on Cu2S chalcocite were performed up to 30GPa using a diamond-anvil cell, He as pressure transmitting medium and synchrotron radiation. Two first-order phase transitions were found at 3.2 and 7.4GPa. The indexation of the powder diffraction patterns suggests three different monoclinic cells for the low-pressure chalcocite and the two high-pressure phases. Subtle changes in the X-ray diffraction patterns suggest a third pressure-induced transition above 26GPa. Structural parameters and compressibility are discussed and compared to those reported in a previous study on Cu2S nanowires.

Influence of growth conditions on hair-like CuS nanowires fabricated by electro-deposition and sulfurization

CuS nanowires were fabricated on an anodized aluminum oxide by electrodeposition and sulfurization. Cu nanowires were first synthesized and then sulfurized to form CuS nanowires. To evaluate the growth conditions including the pH value of the deposition solution, the amount of sulfur powder, and sulfurization temperature, multiple material analysis techniques were conducted. X-ray diffraction was used to characterize the crystalline structure of the nanowire and scanning electron microscopy was used to reveal the morphology of the nanowire. Furthermore, energy-dispersive X-ray spectroscopy and X-ray fluorescence were used to detect the composition of nanowires. Results indicate that an appropriate pH value in the deposition solution, a sufficient amount of sulfur powder and an appropriate sulfurization temperature during surfurization could enhance the growth of the hair-like CuS nanowires with better crystallization and fewer impurities.

CuS Nanoflakes, Microspheres, Microflowers, and Nanowires: Synthesis and Lithium Storage Properties

CuS nanostructured materials, including nanoflakes, microspheres composed of nanoflakes, microflowers, and nanowires have been selectively synthesized by a facile hydrothermal method using CuSO4 and thiourea as precursors under different conditions. The morphology of CuS particles were affected by the following synthetic parameters: temperature, time, surfactant, pH value, solvent, and concentration of the two precursors. The synthesized CuS nanomaterials were characterized by X-ray diffraction, Brunauer-Emmett-Teller N2 adsorption, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The electrochemical tests, including constant current charge-discharge and cyclic voltammetry, show the specific capacities of the different morphologies, as well as their rate capability. The nanowire electrode has near theoretical specific capacity and the best rate capability.

Formation of well-defined Cu2S dendrites on TEM grids from sulfur/CS2 under ambient conditions

The Cu2S dendrites were formed on TEM grids from elemental sulfur (S) in CS2 solution by one day's ageing under ambient conditions and became denser with ageing. The shape and structures were stable in air for at least a month. If S/ethanol solution was dropped on Cu grid, uniform Cu2S nanowires were produced one day later, which could only be obtained by one week's ageing when using S/ethanol suspension as source in our previous work. The influence of the sulfur dispersion and concentration in several kinds of solvent on the growth and structures of Cu2S was discussed based on electron microscopic observation. This simple synthesis method from elemental reactants without any additives was useful for studying formation mechanism of hierarchical nanostructures, and more importantly, it was environmentally friendly.

Room-Temperature Synthesis of High-Density CuS Nanowire Arrays by a Simple Paired Cell

High-density CuS nanoparticle nanowire (NPNW) arrays were successfully synthesized at room temperature by a simple paired cell method. The as-prepared nanowire arrays were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The results indicate that the nanowire diameter is dependent on the pore size of the used ordered porous anodic alumina (OPAA) template and larger than the corresponding pore diameter of the template due to the corrosion effect of Na2S solution on the template. The nanowire is composed of CuS nanoparticles with hexagonal structure. When the reaction time is long enough, the nanowire is solid and composed of nearly spherical CuS nanoparticles. When the reaction time is short, only middle part of the nanowire is solid and composed of nearly spherical CuS nanoparticles, however, the tops are hollow and mainly composed of flake-like nanoparticles. The formation mechanism of CuS nanoparticle nanowires was proposed to be a heterogeneous nucleation, coalescence, aggregation and filling process.

Confined conversion of CuS nanowires to CuO nanotubes by annealing-induced diffusion in nanochannels

Copper oxide (CuO) nanotubes were successfully converted from CuS nanowires embedded in anodic aluminum oxide (AAO) template by annealing-induced diffusion in a confined tube-type space. The spreading of CuO and formation of CuO layer on the nanochannel surface of AAO, and the confinement offered by AAO nanochannels play a key role in the formation of CuO nanotubes.

Gas-phase substitution synthesis of Cu1.8S and Cu2S superlattice nanowires from CdS nanowires

Single-crystalline wurtzite CdS nanowires underwent gas-phase substitution to form unique superlattice cubic Cu1.8S (digenite) and hexagonal Cu2S (chalcocite) structures, using thermal evaporation of CuCl2 at 500∼600 °C. The Cu1.8S nanowires consisted of superlattices along the 〈111〉 direction, with controlled growth direction ([110], [211], [100], [111]) and superlattice periods of 1.6 and 1.9 nm. As the temperature decreased, the growth direction evolved from [100] to the higher surface-energy [110] or [211] directions, with longer superlattice periods. The Cu2S nanowires also exhibited a superlattice along the [0001] growth direction, with a periodicity of 2.7 nm and could be irreversibly converted into superlattice Cu1.8S by electron-beam irradiation.