Preparation by Solvothermal Synthesis, Growth Mechanism, and Photocatalytic Performance of CuS Nanopowders

Chitosan/copper sulfide nanoparticles (CS/CuSNPs) hybrid fibers with improved mechanical and photo-thermal conversion properties via tuning CuSNPs' morphological structures

Conventional textiles are inadequate for maintaining warmth in extremely cold conditions. Therefore, the development of photo-thermal fibers for personal thermal management textiles has emerged as an urgent need. Herein, novel chitosan/copper sulfide nanoparticles (CS/CuSNPs) hybrid fibers with photo-thermal function were fabricated successfully. Significantly, our study demonstrated that the tensile and photo-thermal conversation properties of the CS/CuSNPs hybrid fibers could be effectively regulated by altering the CuSNPs` morphological structures. Compared with other CuSNPs (tube-like, sphere-like, and flower-like), the plate-like CuSNPs with smooth surfaces and uniform nanometer size played a significant role by scattering incident light in the fibers as a secondary light source for CuSNPs absorbance. Thus, under IR light irradiation at a power density of 1.0 W/cm2, the surface temperature of CS/0.1 wt% plate-like CuSNPs hybrid fibers sharply increased by 27.6 °C, which was more than 4 times of the pure CS fibers. And the breaking strength and initial modulus of CS/0.1 wt% plate-like CuSNPs hybrid fibers increased by more than 18.37 and 6.88 % compared with the nascent CS fibers. This study develops a novel and effective strategy to tune the photo-thermal and tensile properties of CS hybrid fibers without incorporating more content or additives.

The Facile Synthesis of Hollow CuS Microspheres Assembled from Nanosheets for Li-Ion Storage and Photocatalytic Applications

Herein, well-defined hollow CuS microspheres assembled from nanosheets were successfully synthesized through a facile solvothermal method. Hollow CuS microspheres have an average diameter of 1.5 μm; moreover, the primary CuS nanosheets have an ultrathin thickness of about 10 nm and are bound by {0001} polar facets. When used as anodes for lithium-ion batteries (LIBs), hollow CuS microspheres exhibit excellent electrochemical properties, including a large discharge capacity (610.1 mAh g^-1 at 0.5 C), an excellent rate capability (207.6 and 143.4 mAh g^-1 at 1 and 5 C), and a superior cyclic stability (196.3 mAh g^-1 at 1 C after 500 cycles). When used as photocatalysts for Rhodamine B (RhB), hollow CuS microspheres can degrade more than 99% of the initial RhB within 21 min. These excellent Li-ion storage properties and photocatalytical performances are attributed to their unique hierarchical hollow structure.

Photo-Sono Interfacial Engineering Exciting the Intrinsic Property of Herbal Nanomedicine for Rapid Broad-Spectrum Bacteria Killing

Large doses and long duration are often required for herbal medicines to kill bacteria effectively. Herein, a photoacoustic interfacial engineering strategy was utilized to endow curcumin (Cur, a kind of herbal medicine) with rapid and highly effective bacteria-killing efficacy, in which Cur was combined with CuS to form a hybrid material of CuS/Cur with tight contact through in situ nucleation and growth on the petaloid CuS surface. Due to the different work functions of CuS and Cur, the interfacial electrons were redistributed, i.e., a large number of electrons gathered on the side of CuS. In contrast, the holes gathered on the side of Cur after contact. An internal electric field was formed to drive the excited electrons to transfer from CuS to Cur, thus enhancing the separation of electron-hole pairs. Besides exerting the drug nature of Cur itself, the CuS/Cur hybrid also had photo-sono responsive ability, which endowed the hybrid with photothermal, photodynamic, and sonodynamic effects. Therefore, this Cur-based hybrid killed 99.56% of Staphylococcus aureus and 99.48% of Escherichia coli under 808 nm near-infrared light irradiation and ultrasound successively for 15 min, which was ascribed to the synergy of ROS, hyperthermia, and released Cu²⁺ together with the drug properties of Cur. This work provides a strategy to enhance the therapeutic effects of herbal medicines against pathogenic bacterial infections by exciting the intrinsic properties of herbal medicines as materials through a photo-sono interfacial engineering strategy.

Gadolinium-doped hollow silica nanospheres loaded with curcumin for magnetic resonance imaging-guided synergistic cancer sonodynamic-chemotherapy

Curcumin is a kind of anti-cancer chemotherapeutic drug and has been demonstrated to be able to produce reactive oxygen species (ROS) under the stimuli of ultrasound (US). Herein, gadolinium-doped hollow mesoporous silica nanospheres (Gd-HMSNs) loaded with curcumin (Cur) and conjugated with carboxymethyl dextran (CMD) have been facilely fabricated and applied for magnetic resonance imaging (MRI)-guided synergistic cancer sonodynamic-chemotherapy. The as-prepared multifunctional theranostic nanoplatform (Cur@Gd-HMSNs-CMD) shows high drug loading capacity, satisfactory biocompatibility, pH-responsive degradation, and US-triggered drug release. Due to the release of Gd³⁺ ions or oligomers during degradation, the nanoplatform Cur@Gd-HMSNs-CMD could serve as an effective contrast agent for T₁-weighted MRI to guide cancer treatment. More significantly, in vivo experiments show that the Cur@Gd-HMSNs-CMD can efficiently inhibit the tumor growth by a high inhibition rate of ~85.6% under US irradiation, mainly resulting from the synergistic effect of sonodynamic-chemotherapy. This innovative "two-in-one" theranostic nanoplatform using a single drug provides a new strategy for developing "all-in-one" nanomaterials for combined cancer treatment.

Amperometric determination of hydrazine using a CuS-ordered mesoporous carbon electrode

An electrocatalytic sensor for hydrazine using copper sulfide-ordered mesoporous carbon (CuS-OMC) is described. A facile solvothermal synthetic strategy was adopted for CuS-OMC and the ordered mesoporous carbon was obtained through nanocasting method. The synthesized CuS-OMC was characterized using microscopic and spectrochemical techniques. CuS-OMC was immobilized on GCE and evaluated for its electrochemical sensing of hydrazine using cyclic voltammetry and amperometry. CuS-OMC modified GCE exhibited better hydrazine sensing at an optimized pH 7.4 in terms of oxidation potential and current compared with that of GCE, CuS, and OMC. The observed sensing performance of CuS-OMC was attributed to the presence of Cu (I/II) in CuS dispersed in OMC which acts as an electrocatalytic center for the sensing of hydrazine. Amperometry under optimized experimental condition with an applied potential of 270 mV was employed to obtain a linear calibration plot in the range 0.25 to 40 μM (R² = 0.9908) with a detection limit of 0.10 μM with a sensitivity of 0.915 (± 0.02) μA cm^-2 μM^-1. Real sample analyses were carried out by spiking of hydrazine in different water samples and the recoveries were in the range of 97 ± 2.1% (n = 3). Graphical abstract.

An Efficient Strategy for the Fabrication of CuS as a Highly Excellent and Recyclable Photocatalyst for the Degradation of Organic Dyes

An effective and practical in situ sulfuration approach has been developed in this work, for the fabrication of CuS with a 3D hierarchical network structure under mild preparation conditions. The prepared CuS consists of a primary structure of the multi-structure interchange copper foam precursor, and a secondary structure of nanoplates. The structural characteristics, morphologies, and photocatalytic performances of the prepared photocatalyst were investigated systematically. To evaluate the photocatalytic performance of the prepared CuS samples, we investigated the degradation of MB (methylene blue), RhB (Rhodamine B), and MB/RhB dye solutions over the samples under the irradiation of simulated solar light. Specifically, the degradation of RhB rapidly reached ≈100.0% after simulated solar light irradiation for 25 min, which is higher than those of P25 (83.0%) and bulk CuS (54.8%). For the mixed systems of MB/RhB, both the degradations of MB and RhB reached up to ≈99.0% after simulated solar light irradiation for 25 min. The superior photocatalytic performances of the prepared samples are attributed to the synergistic effects of high optical absorption, large specific surface area, and abundant active sites. The prepared catalysts can retain the photocatalytic activities during the entire reaction process without significant loss after four catalytic cycles, which reveals that the CuS with a stable 3D hierarchical network structure has a promising prospect as an ideal recyclable catalyst.

RN, Rajamathi JT, Rajamathi M. Microwave-Assisted Synthesis of Porous Aggregates of CuS Nanoparticles for Sunlight Photocatalysis

Solvated two-dimensional nanosheets of copper hydroxy dodecylsulfate in 1-butanol react with thiourea under microwave irradiation to yield surfactant-free porous aggregates of CuS nanoparticles. These aggregates exhibit excellent photocatalytic activity toward degradation of methylene blue, methyl orange, and 4-chlorophenol in natural sunlight. While the high surface area (14.74 m² g^-1) and porosity increase the active reaction centers for adsorption and degradation of organic molecules, quantum confinement results in a low recombination of photogenerated electrons and holes. Chemical and photogenerated hydroxyl radicals cause the oxidation of the dyes and 4-chlorophenol.

Rose-like CuS microflowers and their enhanced visible-light photocatalytic performance

Surfactant-free rose-like copper sulfide (CuS) microflowers were prepared by a simple one-pot solvothermal method in N,N-dimethylformamide (DMF).

Diversified copper sulfide (Cu2-xS) micro-/nanostructures: a comprehensive review on synthesis, modifications and applications

As a significant metal chalcogenide, copper sulfide (Cu_2-xS, 0 < x < 1), with a unique semiconducting and nontoxic nature, has received significant attention over the past few decades. Extensive investigations have been employed to the various Cu_2-xS micro-/nanostructures owing to their excellent optoelectronic behavior, potential thermoelectric properties, and promising biomedical applications. As a result, micro-/nanostructured Cu_2-xS with well-controlled morphologies, sizes, crystalline phases, and compositions have been rationally synthesized and applied in the fields of photocatalysis, energy conversion, in vitro biosensing, and in vivo imaging and therapy. However, a comprehensive review on diversified Cu_2-xS micro-/nanostructures is still lacking; therefore, there is an imperative need to thoroughly highlight the new advances made in function-directed Cu_2-xS-based nanocomposites. In this review, we have summarized the important progress made in the diversified Cu_2-xS micro-/nanostructures, including that in the synthetic strategies for the preparation of 0D, 1D, 2D, and 3D micro-/nanostructures (including polyhedral, hierarchical, hollow architectures, and superlattices) and in the development of modified Cu_2-xS-based composites for enhanced performance, as well as their various applications. Furthermore, the present issues and promising research directions are briefly discussed.

Synthesis and Thermoelectric Properties of Copper Sulfides via Solution Phase Methods and Spark Plasma Sintering

Large-scale Cu2S tetradecahedrons microcrystals and sheet-like Cu2S nanocrystals were synthesized by employing a hydrothermal synthesis (HS) method and wet chemistry method (WCM), respectively. The morphology of α-Cu2S powders prepared by the HS method is a tetradecahedron with the size of 1–7 μm. The morphology of β-Cu2S is a hexagonal sheet-like structure with a thickness of 5–20 nm. The results indicate that the morphologies and phase structures of Cu2S are highly dependent on the reaction temperature and time, even though the precursors are the exact same. The polycrystalline copper sulfides bulk materials were obtained by densifying the as-prepared powders using the spark plasma sintering (SPS) technique. The electrical and thermal transport properties of all bulk samples were measured from 323 K to 773 K. The pure Cu2S bulk samples sintered by using the powders prepared via HS reached the highest thermoelectric figure of merit (ZT) value of 0.38 at 573 K. The main phase of the bulk sample sintered by using the powder prepared via WCM changed from β-Cu2S to Cu1.8S after sintering due to the instability of β-Cu2S during the sintering process. The Cu1.8S bulk sample with a Cu1.96S impurity achieved the highest ZT value of 0.62 at 773 K.

Compound Copper Chalcogenide Nanocrystals

This review captures the synthesis, assembly, properties, and applications of copper chalcogenide NCs, which have achieved significant research interest in the last decade due to their compositional and structural versatility. The outstanding functional properties of these materials stems from the relationship between their band structure and defect concentration, including charge carrier concentration and electronic conductivity character, which consequently affects their optoelectronic, optical, and plasmonic properties. This, combined with several metastable crystal phases and stoichiometries and the low energy of formation of defects, makes the reproducible synthesis of these materials, with tunable parameters, remarkable. Further to this, the review captures the progress of the hierarchical assembly of these NCs, which bridges the link between their discrete and collective properties. Their ubiquitous application set has cross-cut energy conversion (photovoltaics, photocatalysis, thermoelectrics), energy storage (lithium-ion batteries, hydrogen generation), emissive materials (plasmonics, LEDs, biolabelling), sensors (electrochemical, biochemical), biomedical devices (magnetic resonance imaging, X-ray computer tomography), and medical therapies (photochemothermal therapies, immunotherapy, radiotherapy, and drug delivery). The confluence of advances in the synthesis, assembly, and application of these NCs in the past decade has the potential to significantly impact society, both economically and environmentally.

Controllable synthesis of Bi2S3/CuS heterostructures by an in situ ion-exchange solvothermal process and their enhanced photocatalytic performance

A novel Bi₂S₃/CuS hybrid photocatalyst with a 3D hierarchical configuration was synthesized through an in situ solution-based cation exchange reaction that leads to obvious enhancements in charge separation and photocatalytic performance.

Formation of nanoneedle Cu(0)/CuS nanohybrid thin film by the disproportionation of a copper(i) complex at an oil–water interface and its application for dye degradation

A toluene–water planar interface has been used as an ideal template for the self-assembly of a nanoneedle Cu(0)/CuS nanohybrid thin film and Cu(0)/CuS nanoneedles as efficient catalysts for dye degradation.

Facile room-temperature synthesis of carboxylated graphene oxide-copper sulfide nanocomposite with high photodegradation and disinfection activities under solar light irradiation

Carboxylic acid functionalized graphene oxide-copper (II) sulfide nanoparticle composite (GO-COOH-CuS) was prepared from carboxylated graphene oxide and copper precursor in dimethyl sulfoxide (DMSO) by a facile synthesis process at room temperature. The high-effective combination, the interaction between GO-COOH sheets and CuS nanoparticles, and the enhanced visible light absorption were confirmed by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS) and Photoluminescence (PL) spectra. The as-synthesized GO-COOH-CuS nanocomposite exhibited excellent photocatalytic degradation performance of phenol and rhodamine B, high antibacterial activity toward E. coli and B. subtilis, and good recovery and reusability. The influence of CuS content, the synergistic reaction between CuS and GO-COOH, and the charge-transfer mechanism were systematically investigated. The facile and low-energy synthesis process combined with the excellent degradation and antibacterial performance signify that the GO-COOH-CuS has a great potential for water treatment application.

Nanostructured copper sulfides: synthesis, properties and applications

Copper sulfides are the most extensively studied materials due to their non-toxicity, semiconducting nature and tunable properties. In view of this, present review article discusses various synthetic strategies for the fabrication of nanostructured copper sulfides of different morphologies and properties comprehensively followed by their applications in various fields.

A controlled solvothermal synthesis of CuS hierarchical structures and their natural-light-induced photocatalytic properties

A solvothermal synthesis of CuS hierarchical structures for the photodegradation of methylene blue (MB).

Monodisperse CuS nanodisks: low-temperature solvothermal synthesis and enhanced photocatalytic activity

Controllable synthesis of uniformly disk-shaped CuS nanostructures with a narrow size distribution was realized by a low-temperature (150 °C) solvothermal process using polyvinyl pyrrolidone (PVP) as the surfactant.