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CuS nanoparticles (NPs) were synthesized by wet chemical co-precipitation and Solgel method and used to promote photocatalytic degradation of 2-Chlorophenol (2-CP) from aqueous media. The Tauc plot and diffused reflectance spectroscopy (DRS-UV) was studied to determine the 2.1 eV band gap of CuS NPs. The high degree of crystallinity was observed by X-ray diffraction (XRD) analysis. The exothermic nature of CuS NPs was pragmatic at 380oC using thermal gravimetric analysis (TGA) technique. The photo-catalytic activity of CuS NPs towards 2-CPdegradation was influenced with visible light intensity from 20 to 100 W. The strong photocatalytic elimination of 2-CP from an aqueous solution was caused by the increased charge transmission. [ABSTRACT FROM AUTHOR]

Most of the copper sulfide synthetic approaches developed until now are still facing issues in their procedure, such as long synthesis duration, high energetic consumption, and high implementation costs. This publication reports a facile and sustainable approach for synthesizing copper sulfides on a large scale. In particular, an industrial by-product of sulfur waste was used as a sulfurizing agent for copper sulfide synthesis in a water medium. The reaction was performed in the hydrothermal environment by following a novel proposed mechanism of copper sulfide formation. The investigation of morphological and optical properties revealed that the target products obtained by using waste possess the resembling properties as the ones synthesized from the most conventional sulfurizing agent. Since the determined band gap of synthesis products varied from 1.72 to 1.81 eV, the photocatalytic properties, triggered under visible light irradiation, were also investigated by degrading the methylene blue as a model pollutant. Importantly, the degradation efficiency of the copper sulfide synthesized from sulfur waste was equivalent to a sample obtained from a reference sulfurizing agent since the value for both samples was 96% in 180 min. This very simple synthetic approach opens up a new way for large-scale sustainable production of visible-light-driven photocatalysts for water purification from organic pollutants. [ABSTRACT FROM AUTHOR]

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The thin films Fe doped copper sulphide Cu1−xFexS (CFS) (x = 0.01, 0.03, 0.05, and 0.07) were elaborated by spray pyrolysis deposition technique. The characterization by XRD and SEM of the thin films shows a Covellite CuS single phase without formation of other phases. The structure is a simple hexagonal with unit cell dimension, a = b = 3.79 Å and c = 16.34 Å. The Analysis of the UV–Vis spectra reveals that the energy band gap has been decreased from 2.47 to 1.98 eV with the increase of Fe concentration. The absorption coefficients of CFS films have increased from 1.155 × 105 to 1.712 × 105 cm−1. It has demonstrated that a right band gap with a right band edge alignment at a pH value for Fe-doped CFS can boost the material application as a photocatalyst for the visible light. According to this study, CFS (0.07) thin films for a pH = 3 solutions is a promising material for photocatalysis application for water splitting to hydrogen-oxygen production. Nevertheless, we demonstrate that the formation of straddling gap heterostructure for CuS and CFS for a pH solution between 7 and 8 induces the production of oxygen and hydrogen. [ABSTRACT FROM AUTHOR]

The material of CuS/polyvinyl alcohol-chitosan (CuS/PVACS) was prepared with a novel synthesis analysis. The crystallinity, morphological characteristics, and photocatalytic performance of the nano-materials were investigated by X-ray diffraction, field emission scanning electron microscopy X-ray photoelectron, and UV–vis spectrophotometry. The band gap values (Eg) was found as 2.50, and 2.04 eV for CuS, and CuS/PVACS nano-catalyst, respectively. The photo-degradation amount of the malachite green solutions which were degraded by CuS/PVACS in the UV-irradiation in 60 min was above 96.51%. The antibacterial properties of the CuS/PVACS has been evaluated versus (G+/G-) bacteria. The results of antibacterial performance indicated that CuS/PVACS nanocomposites have bacteriostatic behavior versus Escherichia coli , Pseudomonas syringae , Staphylococcus aureus and Streptococcus pneumoniae. [ABSTRACT FROM AUTHOR]

The stable and efficient CuS photocatalyst was elaborated by the facile hydrothermal route at 140 °C for various durations, from copper chloride (CuCl 2) and thiourea (SC(NH 2) 2) aqueous solutions. Characterization techniques such as X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) coupled with energy-dispersive of X-ray system (EDX) analysis, showed the formation of pure CuS nanomaterial. Electrochemical impedance spectroscopy (EIS) revealed that synthesized CuS exhibited a quick charge transfer at high frequencies and a diffusion or transport of ions from the electrolyte to the electrode surface at medium and low frequencies. Hall effect measurement indicated that all prepared CuS are a p-type semiconductors with a hole concentration on the order of 1020 cm−3. A decrease in the hole concentration with increasing heat treatment duration was observed and related to the healing of Cu vacancies. Transmittance and absorbance measurements showed that all samples interacted with light, exhibiting a prominent peak around 600 nm. Tauc method revealed an increase of the optical band gap values from 1.56 to 1.75 eV with the increment of heat treatment duration. Photocatalytic activity of CuS prepared at 140 °C for 16 h was determined by measuring the degradation rate of methylene blue (MB) dye under UV light in the absence and presence of hydrogen peroxide (H 2 O 2). The results demonstrate CuS as a stable and efficient photocatalyst and underscore its potential for application in wastewater purification processes. [Display omitted] • Hydrothermal synthesis of CuS nanomaterials. • Electrical and optical properties of CuS. • Growth mechanism of CuS by hydrothermal route. • Photocatalytic Activity of CuS. [ABSTRACT FROM AUTHOR]

This work is focused on a systematic study of homogeneous growth of copper sulfide (CuS) thin films deposited under similar chemical deposition conditions and considering the variations of the number of dips during the chemical bath deposition process. The aim of this work is to investigate the influence on the structural, optical and electrical properties of CuS films when varying the deposition parameters aforementioned. The films were deposited at 27 °C during 45, 60, 75 and 90 minutes per dip. The CuS thin films presented an amorphous structure. The Raman spectra showed one band at 475 cm-1 (Eg) which corresponds to the CuS vibration. These notable characteristics are preserved in the samples obtained from all dips. The energy band gap values are in the range from 1.65 to 2.6 eV, the former value corresponding to the three dip process. The conductivity of CuS films increased as the grain size increased. These characteristics in CuS films make them suitable candidate for various semiconductor device applications, obtained by a rapid and low- cost technique. [ABSTRACT FROM AUTHOR]

In this work, copper sulphide (CuS) thin films were deposited on glass substrates by chemical bath deposition method under different pH, deposition temperature, stirring speed and deposition time. The effects of process parameters, such as pH from 1.8 to 2.2, deposition temperature from 30 to 50 °C, stirring speed from 50 to 250 rpm and deposition time from 8 to 40 h on the band gap, were optimized by central composite design (CCD) of response surface methodology (RSM). Five-level-four-factor CCD was employed to evaluate the effects of the deposition parameters on the band gap of CuS thin films. A quadratic model was established as a functional relationship between four independent variables and the band gap. Analysis of variance revealed that the proposed model was adequate. The optimum pH, deposition temperature, stirring speed and deposition time were found to be 2.10, 44.33 °C, 200 rpm, and 32 h, respectively. Under these conditions, the experimental band gap of CuS was observed as 2.74 eV, which was well in close agreement with predicted value (2.71 eV) by the model. [ABSTRACT FROM AUTHOR]

Nanonail shaped ZnS-CuS-Bi three component nanoparticles are synthesized via a simple one-pot colloidal synthesis route by thermal decomposition of metal-thiolate precursors. A thiol serves as the sulfur source and a phase directing capping agent promotes selective anisotropic growth of the nanocrystals in a noncoordinating solvent. After the nucleation and growth of a CuS rod, reactive Cu ions serve as catalytic seeds for the nucleation and growth of ZnS and Bi at the CuS nanorod tips. Thereby the obtained ZnS-CuS-Bi nanocrystals form a chain of two semiconductors of decreasing band gap and a metallic Bi nanoparticle. The three components absorb light in different spectral regions enabling efficient light harvesting. Furthermore, the band edge alignment of ZnS and CuS promote photogenerated electron funneling towards the Bi catalyst particle, which promotes charge carrier separation, effectively channeling the catalytic activity. The photocatalytic performance is assessed at the example of the photodegradation of the organic dye Rhodamine B, and shows excellent performance rendering these nanonails as inexpensive, non-toxic and efficient photocatalyst to remedy environmental pollution. [Display omitted] • One-pot synthesis of 1D heterostructures. • Bi based novel photocatalyst. • Charge carrier dynamic pointing towards a funneling effect. • Photocatalytic dye degradation for waste water treatment and environmental preservation. [ABSTRACT FROM AUTHOR]

In this study, the novel Bi 2 WO 6 /CuS/g-C 3 N 4 ternary heterojunctions with highly efficient visible-light photocatalytic performance were synthesized, which were then applying in the degradation of ciprofloxacin (CIP) in wastewater. The characterization data demonstrated that the heterojunction interfaces were formed between Bi 2 WO 6 , CuS and g-C 3 N 4 , which effectively narrowed the band gap. Moreover, coupling CuS with g-C 3 N 4 inhibited the recombination of photogenerated e − and h+ pairs and accelerated the interfacial charge transfer; as a result, Bi 2 WO 6 /CuS/g-C 3 N 4 possessed enhanced visible-light photocatalytic performance. Importantly, it has been confirmed that the photogenerated e −, h + and O 2 −were main active species generated by Bi 2 WO 6 /CuS/g-C 3 N 4 for photodegradation, which realized simultaneous redox reactions for the effective degradation of CIP (74.94 %, 75 min) and RhB (99.66 %, 90 min). Besides, the great chemical stability enabled Bi 2 WO 6 /CuS/g-C 3 N 4 to maintain nearly the same photodegradation efficiency for CIP degradation after four repeated cycles. Taken together, this study provided not only a feasible method for synthesizing the novel Bi 2 WO 6 /CuS/g-C 3 N 4 ternary heterojunctions with highly efficient visible-light photocatalytic performance, but also a way for purifying CIP in wastewater. [ABSTRACT FROM AUTHOR]

In this paper, copper base sulfide nanoparticles (Cu 2 S, CuS, CuO/Cu 2 O/Cu 2 S, Cu 2 S/CuS, CuS/S) were synthesized in polyethylene glycol (PEG)-400 by a one-step method and by tuning the molar ratios of Cu:S (1:0.1–1:3) with copper acetate and sublimed sulfur as sources. The interaction of elemental sulfur with copper ion in PEG was analyzed in detail to elucidate the formation mechanism. With the change of the molar ratio of copper to sulfur, the products exhibit a variety of composition, morphology and size. When the molar ratio of copper to sulfur is 1:1, the product is CuS nanoflakes with particle size of 200–300 nm and thickness of 30 nm. The CuS nanoflakes with a smaller band gap value of 2.01eV can photodegrade 96% (48 mg/g) of rhodamine B (RhB) in 5 min in the presence of H 2 O 2. This route is simple, environmentally friendly and it offers a more promising way to prepare different morphologies and compositions of Copper Base Sulfide Nanoparticles (CBSN). Image 1 • Copper Base Sulfide Nanoparticles were synthesized by a simple and green method. • The ratios of precursors determine the composition and morphology of the products. • The products exhibit good photocatalytic activity under visible irradiation. • The interaction of sulfur with copper ion in PEG was analyzed in detail. [ABSTRACT FROM AUTHOR]

Solar hydrogen generation through photo-electrochemical (PEC) water splitting is potential technology but equally challenging to address the growing energy demand as well as the concerns related to the use of fossil fuels, and several strategies have been devised to address these concerns. Herein, we report a nanohybrids of copper sulfides supported on nickel-incorporated graphitic carbon nitride (Ni/g-C 3 N 4 @CuS) sheets for enhanced activity towards PEC water oxidation. The TEM images confirm the presence of intimate contact between nickel doped graphitic carbon nitride and CuS, forming an interface which is favorable for an effective separation of charge-carriers. The electrochemical properties of the prepared samples are investigated through linear sweep voltammetry, electrochemical impedance spectroscopy, Mott-Schottky analysis, and chopped photo-current measurements. The Ni/g-C 3 N 4 @CuS nanohybrids depicts almost three-fold enhancement in current density under light illumination reaching to 15.5 mA cm−2 at an over potential of ca. 600 mV than in the dark and almost fifteen-fold enhancement as compared to its parent materials, CuS and g-C 3 N 4. The enhanced activity towards PEC water splitting is assigned to the larger extent of band bending as illustrated by larger space charge region width, formation of p-n junction between CuS and g-C 3 N 4 , lowering of effective band gap of the resulting hetero-structures, and facile charge transfer kinetics due to Ni-incorporation into the g-C 3 N 4 matrix. Image, graphical abstract [ABSTRACT FROM AUTHOR]

CuS nanoflowers were loaded on anatase TiO2/polyvinylidene fluoride (PVDF) fibers by hydrothermal treated electrospun tetrabutyl orthotitanate (TBOT)/PVDF fibers at low temperature. The results indicated that the amount of copper source and sulfur source determined the crystallization and morphology of the resultant products. It was found that the composite of CuS narrowed the band gap energy of TiO2 and enhanced the separation efficiency of the photogenerated electron-hole pairs of TiO2. The photocatalytic reaction rate of CuS/TiO2/PVDF fibers to rhodamine B was 3 times higher than that of TiO2/PVDF fibers under visible light irradiation. Besides, owing to the preparation process was carried out at low temperature, the flexibility of CuS/TiO2/PVDF fibers was ensured. In addition, the self-cleaning performance of the dye droplets on the resultant product surface was demonstrated under visible light. Meanwhile, the resultant product can automatically remove dust on the surface of the material under the rolling condition of droplets due to its hydrophobicity. Therefore, the as-prepared CuS/TiO2/PVDF fibers can not only degrade the contaminated compounds, but also depress the maintenance cost owing to its self-cleaning performance, which means a very practical application prospect. [ABSTRACT FROM AUTHOR]