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Copyright of International Journal of Advances in Engineering & Pure Sciences is the property of Marmara University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Photocatalytic technology, as one of the most promising environmental remediation tools, has a wide range of applications in the field of removing antibiotic-based pollutants from wastewater. Therefore, to obtain efficient green and inexpensive photocatalysts, a p–n type Bi2MoO6/CuS composite photocatalyst modified by lignin carbon quantum dots (CQDs) was successfully prepared by solvothermal in situ co-precipitation in this study. It was used to achieve efficient photocatalytic degradation of tetracyclic hydrochloride antibiotics (TCH). The composites were systematically characterized by XRD, FTIR, XPS, SEM, TEM, EIS, nitrogen adsorption–desorption test, and UV–Vis DRS regarding crystal structure, microscopic morphology, and photoelectric properties. The results showed that the prepared samples had good crystallinity and high purity. The photocatalytic degradation experiments further demonstrated that the Bi2MoO6/CuS composites modified by CQDs exhibited excellent photocatalytic activity compared to Bi2MoO6 and CuS monomers wherein CQDs@Bi2MoO6/CuS 2 was the most effective, with a TCH removal of 96.98% and a degradation rate constant (K) of 0.04405 min−1 after 60 min of light exposure. The TCH removal could be maintained at 78.25% after four cycles. The ESR and LC–MS experiments demonstrated that h+ and ·O2− were the main active substances for photocatalytic degradation of TCH. This work provides an efficient catalyst for TCH removal and offers new ideas for applying p–n heterojunction composites in photocatalysis. [ABSTRACT FROM AUTHOR]

Chromium is a common heavy metal contaminant that is widely used in various industrial processes. CuS-Bi2WO6/CNFs composite photocatalysts with different CNFs(active carbon nanofibers) content were prepared by solvothermal method to improve the reduction of hexvalent chromium under visible light irradiation. The samples underwent characterization using XRD, SEM, TEM, XPS, UV–Vis, PL, and photocurrent techniques to analyze their crystal shape, morphology, structure, elemental composition, surface functional groups, and optical properties. Additionally, the photocatalytic reduction activity of Cr(VI) was investigated. The findings demonstrated a notably enhanced photocatalytic activity in CuS-Bi2WO6/CNFs composites compared to CuS, Bi2WO6, and CuS-Bi2WO6 individually. In the presence of visible light, 1% CuS-Bi2WO6/CNFs showed excellent photocatalytic activity for Cr(VI) reduction, with a reduction rate of 98% within 3 h. Furthermore, after four cycles, the 1% CuS-Bi2WO6/CNFs composite demonstrated consistent stability and recyclability. Additionally, an active group capture experiment revealed the involvement of hydroxyl radicals (•OH), photogenerated holes (h+), and superoxide radicals (•O2−) in the reduction of Cr(VI) by CuS-Bi2WO6/CNFs, with •O2− emerging as the primary active species in the system. Based on these findings, we investigated the photocatalytic reaction mechanism. This study underscores the feasibility of preparing CuS-Bi2WO6/CNFs through a straightforward and manageable solvothermal approach, affirming the promising potential of CuS-Bi2WO6/CNFs composites in hexavalent chromium treatment. [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]

Semiconductor-based photocatalysis represents a promising technology for removing antibiotic given its cost effectiveness and environmental compatibility. However, finding suitable photocatalysts and semiconductors for practical applications can be challenging. This work aims to investigate the photocatalytic performance of as-synthesized photocatalysts under broad-spectrum from visible (Vis) to near-infrared (NIR) sunlight. In this work, a step-scheme (S-scheme) heterojunction photocatalyst, i.e., CuS/S–C 3 N 4 , was prepared, employing a single-step hydrothermal route. The synthesized photocatalyst showed excellent crystallinity and high purity content. The CuS loading provided a better NIR light response-ability and improved photocatalytic activity for CuS/S–C 3 N 4. The 2 wt% CuS/S–C 3 N 4 produced the highest tetracycline (TC) photodegradation rate, up to about 95% efficiency under Vis + NIR light irradiation. The result also showed that the 2 wt% CuS/S–C 3 N 4 sample had a first-order kinetic constant (k) that was 6.2-fold higher than the pure S–C 3 N 4 sample under Vis + NIR light irradiation. However, too much CuS content led to the presence of inactive sites on S–C 3 N 4 , which hampered the light absorption ability, thus leading to inadequate photocatalytic activity. In addition, the 2 wt% CuS/S–C 3 N 4 sample also showed high photocatalytic stability and insignificant change of the composite structure before and after the experiments. In short, we can enhance the CuS/S–C 3 N 4 photocatalytic activity by increasing the light response range and the separation efficiency of light-induced electrons and holes. Consequently, we have developed a novel strategy and experimental basis for S-scheme heterojunction to be fully utilized under broad-spectrum sunlight. [ABSTRACT FROM AUTHOR]

Bis(thiomorpholinyldithicarbamate)Cu(II) complex was prepared and characterized by single crystal X-ray crystallography. The molecular structure revealed a mononuclear copper(II) ion bonded to two thiomorpholinyl dithiocarbamate anion to form a distorted square planar geometry. The compound was thermolyzed at 130°C to prepare CuS nanoparticle confirmed as pure hexagonal covellite crystalline phase by powder X-ray diffraction (pXRD). HRTEM image showed CuS nanoparticle with particle sizes in the range 23.3–48.8 nm. The lattice fringes confirm polycrystalline nanoparticles with an interplanar distance of 0.24 nm that corresponds with the lattice plane (101) of hexagonal CuS. SAED patterns confirmed the crystallinity by showing two separate diffraction rings ascribed to (101) and (102) lattice planes of hexagonal CuS phase. The CuS nanoparticles exhibited excellent photocatalytic activity for methylene blue (MB) and methyl orange (MO) dyes degradation. [ABSTRACT FROM AUTHOR]

• CuS-AgVO 3 /Ag-TNR materials were fabricated via an ultra-sonication method. • AgVO 3 /Ag provides good stability, high conductivity and electron-storing capacity. • CuS acts as co-catalyst and suppress the charge carrier recombination. • CuS-AgVO 3 /Ag-TNR shows higher photocatalytic H 2 yield (756 µmol/g). • 1 wt% CuS-AgVO 3 /Ag-TNR heteronanostructure is stable for up to 15 h. Recently, the frenetic development of stable quaternary material with a wide range of solar energy absorption and separation of charge carrier has emerged as a favorable material for the solar-to-hydrogen conversion. In this work, quaternary CuS-AgVO 3 /Ag-TNR heteronanostructures (HNSs) synthesized by an ultra-sonication method for stabilized solar light photocatalytic hydrogen production in glycerol-water mixture. Among the prepared photocatalysts, the 1 wt% CuS-AgVO 3 /Ag-TNR HNS produced the highest H 2 activity (756 µmol/g), approximately 84 times greater than the TNR due to higher charge separation, excellent conductivity, plasmonic resonance effect, and electron-storing capacity. Interestingly, the accelerated charge transfer pathway through the Schottky junction between the AgVO 3 and Ag to the conduction band of the TNR and thereafter to the electron acceptor of CuS for the reduction of H+ ions to H 2. Additionally, a possible photocatalytic mechanism of CuS-AgVO 3 /Ag-TNR HNS for improved H 2 production was proposed based on the results obtained by various characterization techniques. Therefore, present research work explores the new insights to design high-performance CuS-AgVO 3 /Ag-TNR HNS material for the conversion of clean renewable H 2 energy for the futuristic transport applications. [ABSTRACT FROM AUTHOR]

• Photocatalytic activity of CuS NPs greatly improved upon immobilizing on PNIPAM. • CuS NPs with PNIPAM hydrogels enhance photothermal–photocatalytic performance. • Positive influence of the NIR-induced temperature increase is demonstrated. This study explores the synergistic effects of photothermal and photocatalytic properties by investigating CuS nanoparticles immobilized on poly(N-isopropylacrylamide) (PNIPAM) polymer. The photothermal-photocatalytic decomposition test of organic dye demonstrated a significant enhancement in photocatalytic activity upon immobilizing CuS on PNIPAM. The closer proximity of CuS nanoparticles, induced by the photothermal effect of CuS and PNIPAM shrinkage, led to improved heat generation and enhanced photocatalytic performance under simultaneous ultraviolet and infrared light irradiations. [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]

CuS/CdS(H)/CdS(C) photocatalysts were synthesized via the hydrothermal method by employing thiourea, Cd(CH 3 COO) 2 ·3H 2 O and copper 1,4-benzenedicarboxylate MOF (CuBDC). The photocatalysts were characterized by XRD, XPS, BET, TEM and UV–vis diffuse reflectance spectra. Interestingly, hexagonal CdS (CdS(H)) and cubic CdS (CdS(C)) were formed with phase junctions in one step when CuBDC was introduced in the synthesis process, in addition, CuS nanoparticles were deposited on CdS. However, only hexagonal CdS was obtained without CuBDC. It demonstrated that CuBDC was not only the precursor of CuS but also the structural modifier for CdS. With the reduction of re-combination of photo-induced electrons and holes caused by phase junctions and the enhancement of visible-light absorptions due to the loading of CuS, all CuS/CdS(H)/CdS(C) photocatalysts had higher photocurrent densities under visible-light irradiation, and consequently the higher rates of H 2 production than pure CdS(H). Typically, the catalyst with 2.89 wt% of Cu showed a highest rate of H 2 evolution at 2042 μmol/g/h. Image 1 • Cu-MOF acts as structural modifier leading to formation of CdS(H)/CdS(C) phase junction. • CdS(H)/CdS(C) with phase junction has narrower band gap than pure CdS(H). • Deposited CuS enhances the light absorption in the region between 550 nm and 800 nm. [ABSTRACT FROM AUTHOR]

Free-standing carbon nanotube films (CNTF) with entangled carbon nanotubes (CNT) were used as conductive supports for the preparation of CuS–ZnS/CNTF composite as immobilized photocatalysts for H 2 production. The surface morphology, crystalline property, surface chemistry, and optical properties of the CuS–ZnS/CNTF photocatalysts were investigated. The effects of forming CuS–ZnS heterojunction and conductive CNTF on the separation of photogenerated charges and photocatalytic hydrogen production activity of CuS–ZnS/CNTF photocatalysts were evaluated by the photocatalytic hydrogen production tests. Conductive CNT films can prevent the recombination of photogenerated electron–hole pairs. The deposition of CuS nanoparticles on the ZnS/CNTF leads to higher photocatalytic activity which can be attributed to the effective electron–hole separation. Introducing ZnS and CuS makes the photocatalyst surface more hydrophilic. The porous structure contributed to the effective contact between the sacrificing agents and the photocatalysts, leading to enhanced H 2 production activity. • Free-standing carbon nanotube film (CNTF) were used to make immobilized photocatalysts. • Introducing ZnS and CuS makes the photocatalyst surface more hydrophilic. • The improved H 2 production activity results from the enhanced charge separation. • The activity was improved by forming CuS–ZnS heterojunction on conductive CNTF. • The porous structure and the hydrophilic nature enhance the contact between the sacrificing agents and the photocatalysts. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The CuS/Bi 4 Ti 3 O 12 p-n heterojunction material were synthesized. • Flower like hierarchical structures with improved visible light absorption. • Intra-electric field and microscopic contact are vital for photocatalytic activity. • CuS/Bi 4 Ti 3 O 12 materials highly active for MCPA degradation under visible light. • The mechanistic details of MCPA degradation is illustrated. Abstract In this study, a series of CuS/Bi 4 Ti 3 O 12 p-n heterojunction materials were synthesized by a two-step process. Initially, the Aurivillius phase Bi 4 Ti 3 O 12 (BT) was synthesized by a facile combustion route using urea as a fuel. The Bi 4 Ti 3 O 12 was subsequently modified by deposition of CuS (5–20 wt%) using a hydrothermal route to prepare the heterojunction materials. The methods of synthesis and calcination temperature were important factors which influenced the morphology, particle size and phase purity of Bi 4 Ti 3 O 12 material. Phase pure BT nanoplates with planar dimension of 150–200 nm and thickness between 50 and 70 nm were obtained at a calcination temperature of 600 °C. Pure CuS prepared by hydrothermal method, contained hierarchical microspheres with diameter in the range of 1.2–1.6 μm. The heterostructure materials exhibited hierarchical flower like structure consisting of ultrathin CuS nanosheets and BT-nanoflakes. HRTEM and microstructural study revealed microscopic close interaction between the two phases. The optical and electrical measurement study suggested significant improvement in visible light absorption (400–800 nm) and charge carrier separation due to heterojunction formation. The CuS/Bi 4 Ti 3 O 12 materials showed excellent photocatalytic activity for aqueous phase degradation of 2-methyl-4-chlorophenoxyacetic acid (MCPA) herbicide under visible light (>95% degradation in 3 h). The rate constant for CuS/Bi 4 Ti 3 O 12 materials was 4.5 times higher than the pure BT material towards MCPA degradation. The OH and O 2 – radicals have been identified as the reactive species, the formation of which was confirmed by spectrometric method using terephthalic acid and nitroblue tetrazolium as molecular probes. The mechanism of MCPA degradation over the photocatalyst surface has also been elucidated using LC-ESI-MS, TOC and scavenger experiments. [ABSTRACT FROM AUTHOR]

Three-dimensional porous CuS/graphene photocatalysts had been successfully prepared by twostep solvothermal method and exhibited outstanding adsorption synergistic photodegradation for anion dyemethyl orange (MO). Due to the combination of the adsorption of graphene porous aerogel and the photocatalysis of CuS, the CuS/graphene photocatalysts could rapidly enrich the methyl orange and effectively degrade MO in suit. The degradation rate of MO went up to as high as 92.94% by the CuS/graphene composites in 55 min through the synergistic effect of adsorption photocatalytic, which was about 2.9 times more than that of bare CuS. The obviously improved photodegradation rate was attributed to the excellent adsorption performance and high charge mobility of the porous graphene substrate. Moreover, its MO removal efficiency still remained 79.47% after 3 times cyclic experiments. Meanwhile, due to its special 3D porous network structure, the CuS/graphene composites could efficiently separate from the solution without assistance of filtering. Therefore, the CuS/graphene composites with the synergy of adsorption and photocatalysis would be a promising strategy for practical dye wastewater treatment. [ABSTRACT FROM AUTHOR]

CuS-WO 3 composites were synthesized by an in situ solution method at low temperature. The crystalline phase, morphology, particle size, and the optical properties of CuS-WO 3 samples were characterized by XRD, SEM, XPS, and UV–vis diffuse reflectance spectra. CuS-WO 3 composites showed much higher activity for photocatalytic degradation of RhB as compared with WO 3 and CuS. The degradation rate constant over 1 wt% CuS-WO 3 catalyst was 4.4 times and 9.2 times higher than that of WO 3 and CuS, respectively. It is found that holes (h + ) and superoxide radical anions ( O 2 − ) are the dominant reactive species by using methanol, disodium ethylenediaminetetraacetate (EDTA) and ascorbic acid as scavengers. Band structure analysis shows that bottom of CB of WO 3 is very similar with and higher (ca. 0.01 eV) than the top of VB of CuS. The results of PL showed that the similarity renders the recombination between photogenerated holes on the VB of CuS and photogenerated electrons on the CB of WO 3 possible and easy, forming a direct Z-scheme in CuS-WO 3 . This result in that more electrons in the CB of CuS and holes in the VB of WO 3 survived, and then participated in the photocatalytic degradation of RhB, showing an increased activity. [ABSTRACT FROM AUTHOR]

A novel CuS ZnS 1−x O x /g-C 3 N 4 nanocomposites were prepared by a thermal decomposition process and a hydrothermal method. The effects of the Cu(NO 3 ) 2 dopant precursor concentration and weight ratio of g-C 3 N 4 /ZnS 1−x O x on the morphology, crystalline properties, optical property, photocurrent were investigated by using the field-emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectra (DRS), photocurrent response, and hydrogen production tests. Decorating CuS improved the absorption of the heterostructured photocatalysts. H 2 production rate was increased from 9200 to 10,900 μmol h −1 g −1 by incorporating CuS. By loading 5 wt% g-C 3 N 4 on CuS ZnS 1−x O x , the maximal hydrogen production rate of the composite catalyst reached 12,200 μmol g −1 h −1 under UV light irradiation. Introducing g-C 3 N 4 helps to separate photogenerated electron–hole pairs. After being operated for 3 cycles, the recycled CuS ZnS 1−x O x /g-C 3 N 4 photocatalyst retained 87% of its original activity. [ABSTRACT FROM AUTHOR]

In this work, novel CuS/g-C 3 N 4 composite photocatalysts were successfully prepared via a simple in-situ growth method. CuS nanoparticles, with an average diameter of ca.10 nm, were well dispersed on the surface of g-C 3 N 4 , revealing that g-C 3 N 4 nanosheets were promising support for in-situ growth of nanosize materials. The CuS/g-C 3 N 4 composites exhibited highly enhanced visible light photocatalytic H 2 evolution from water-splitting compared to pure g-C 3 N 4 . The optimum photocatalytic activity of 2 wt% CuS/g-C 3 N 4 composite photocatalytic H 2 evolution was about 13.76 times higher than pure g-C 3 N 4 . The enhanced photocatalytic activity is attributed to the interfacial charge transfer (IFCT). In this system, electrons in the valence band (VB) of g-C 3 N 4 can transfer directly to CuS clusters, causing the reduction of partial CuS to Cu 2 S, which can act as an electron sink and co-catalyst to promote the separation and transfer of photo-generated electrons. The accumulated photoinduced electrons in CuS/Cu 2 S clusters could effectively reduce H + to produce H 2 . This work provides a possibility for constructing low-cost CuS as a substitute for noble metals in the photocatalytic production of H 2 via a facile method based on g-C 3 N 4 . [ABSTRACT FROM AUTHOR]

The photocatalytic activity of Bi 4 Ti 3 O 12 is limited by the lack of active sites and rapid carrier recombination. In this work, the problems mentioned above are effectively solved by using a dual functional CuS load on the surface of Bi 4 Ti 3 O 12. The CuS can be used as electron trapping sites to play a role as a cocatalyst, and form p-n junction with the Bi 4 Ti 3 O 12 under irradiation through the properties of p-type semiconductor. The dual functionality of CuS effectively promotes carrier separation and enhances the photocatalytic degradation activity. The photocatalytic rate of Bi 4 Ti 3 O 12 with optimal loading amount of CuS is ∼1.8 and ∼2.7 times as high as that of the Bi 4 Ti 3 O 12 and the CuS, respectively. The photocatalytic mechanism of the Bi 4 Ti 3 O 12 –CuS system is investigated in detail. • CuS can be used as electron trapping sites to play a role as a cocatalyst. • CuS form p-n junction with Bi 4 Ti 3 O 12 under irradiation through the properties. • The dual functionality of CuS effectively promotes carrier separation. [ABSTRACT FROM AUTHOR]

To solve the emerging aromatic organic pollutants in aqueous environment, in this study, the efficient recyclable core-shell structured photocatalyst Fe 3 O 4 @PDA/CuS was prepared by in situ reduction method. Firstly, Fe 3 O 4 as cores were prepared to provide magnetic recovery. Through the self-polymerization of dopamine (DA), polydopamine (PDA) was coated on Fe 3 O 4 as shells to protect Fe 3 O 4 cores. Then, Cu2+ coordinated with PDA on the surface of Fe 3 O 4 @PDA and in situ reduced by Na 2 S to obtain core-shell structural Fe 3 O 4 @PDA/CuS with CuS uniformly growing on the PDA. CuS with a narrow band gap will endow Fe 3 O 4 @PDA/CuS excellent photocatalytic performance for organic dyes degradation. The decomposition rate of methylene blue (MB) reached to 92.1 % within 180 min under visible light irradiation of Fe 3 O 4 @PDA/CuS as photocatalyst without any cocatalyst. When pH= 10, the decomposition rate of MB can reach to 92.7 % in 60 min, indicated Fe 3 O 4 @PDA/CuS was more suitable for use under alkaline conditions. The capture experiment determined that·OH was the main active substance. This also explained that under alkaline conditions, numerous OH- was conducive to the formation of ·OH, thus accelerated the degradation rate. And the decomposition rate of MB by Fe 3 O 4 @PDA/CuS can still reach 83.95 % after reused three times. [Display omitted] • Fe 3 O 4 @PDA/CuS was prepared by a simple in situ reduction method. • Fe 3 O 4 @PDA/CuS was more suitable for use under alkaline conditions. • Fe 3 O 4 @PDA/CuS exhibited efficient photocatalytic activity towards organic dye without cocatalyst. • Fe 3 O 4 @PDA/CuS can be separating and recycling to avoid secondary pollution. [ABSTRACT FROM AUTHOR]

Morphologically controllable copper sulfide (CuS) nanoneedle, nanowall, and nanosheet networks on copper substrates have been fabricated by a simple, facile, and fast method based on low-temperature chemical vapor deposition through simply adjusting the reaction conditions such as the temperature and flow rate of argon gas. The compositional and structural analyses indicated that all the obtained nano-networks were single-crystalline. And their growths were possibly controlled by a solid–liquid–solid mechanism. The photocatalytic activities of the different shaped CuS nanostructures have been evaluated by their photodegradation on rhodamine B and methylene blue in aqueous phase, which revealed that in both cases the CuS nanoneedles nano-network exhibited better performance than the other two nanostructures. [ABSTRACT FROM PUBLISHER]

Abstract: High quality CuS and CuS/ZnS core/shell nanocrystals (NCs) were synthesized in a large quantity using a facile hydrothermal method at low temperatures of 60°C and evaluated in the photodegradation of Rhodamine B (RhB) under visible light irradiation. Synthesis time plays an important role in controlling the morphology, size and photocatalytic activity of both CuS and CuS/ZnS core/shell NCs which evolve from spherical shaped particles to form rods with increasing reaction time, and after 5h resemble “flower” shaped morphologies in which each “flower” is composed of many NCs. Photocatalytic activity originates from photo-generated holes in the narrow bandgap CuS, with encapsulation by large bandgap ZnS layers used to form the core/shell structure that improves the resistance of CuS towards photocorrosion. Such CuS/ZnS core/shell structures exhibit much higher photocatalytic activity than CuS or ZnS NCs alone under visible light illumination, and is attributed to higher charge separation rates for the photo-generated carriers in the core/shell structure. [Copyright &y& Elsevier]

Abstract: CuS nanostructures have been prepared by hydrothermal route using copper nitrate and thiourea as copper and sulfur precursors. Investigations were done to probe the effect of cationic surfactant viz. cetyl trimethyl ammonium bromide on the morphology of the products. Further studies have been done to know the influence of reaction time on the morphology of CuS nanostructures. Results demonstrated that the morphology of CuS was influenced by the reaction time and surfactant. X-ray diffraction pattern showed that the as-prepared CuS nanostructures were in pure hexagonal phase and UV–vis spectra reveal a strong absorption in the visible region of 400–800nm. A detailed mechanism has been elucidated for the growth of CuS nanostructures. The photocatalytic activity was evaluated by the decolorization of methylene blue (MB) dye under visible-light irradiation and results showed that 87% of the dye was degraded. Thus the as-prepared CuS catalysts are highly promising materials for photocatalytic applications towards dye degradation. [Copyright &y& Elsevier]

A robust, ternary photocatalyst, GO-FA-CuS was prepared by covalent conjugation of folic acid (FA) to graphene oxide (GO) nanosheets and subsequent deposition of CuS nanoflowers. [Display omitted] • A robust, ternary photocatalyst, GO-FA-CuS has been prepared. • GO-FA-CuS was able to explicit degradation of toxic dyes. • Photocatalytic activity of GO-FA-CuS was higher in NIR laser. • Photothermal effect is responsible for higher activity in NIR laser. • GO-FA-CuS is an stable reusable photocatalyst. A robust, ternary photocatalyst, GO-FA-CuS was prepared by covalent conjugation of folic acid (FA) to graphene oxide (GO) nanosheets and subsequent deposition of CuS nanoflowers. The photocatalytic efficiency of GO-FA-CuS was evaluated by degradation rate of industrially versatile used dyes, rhodamine B, methylene blue, methyl orange and alizarin red s by irradiating to near-infrared (NIR) laser. The complete degradation of all four dyes was attained by excellent photocatalytic activity of GO-FA-CuS. Incorporation of GO, FA and CuS in GO-FA-CuS, significantly improved their individual photocatalytic activity with several fold. In GO-FA-CuS, GO and CuS were performed as a collector of holes and captor of electrons, respectively. The blending of FA with GO and CuS, tuned the GO-FA-CuS as an efficient photocatalyst and opened a new era of FA in photocatalysis, apart from its classical application in biomedical field. The hierarchical structured, GO-FA-CuS emerged with important benefits, viz., efficient suppression of recombination of photogenerated electrons and holes, higher adsorption of dye molecules and elevated harvesting of NIR light. The photocatalytic activity of GO-FA-CuS in degradation of rhodamine B was higher under exposure to NIR laser rather than UV, visible and sunlight. The facile degradation of rhodamine B found in NIR laser was influenced by photothermal effect. GO-FA-CuS possessed the negative surface charge, because of that, its photocatalytic activity was higher in degradation of cationic dyes, rhodamine B and methylene blue compared to anionic dyes, methyl orange and alizarin red s. The GO-FA-CuS demonstrated significant stability and easy recycling ability for repeated use. [ABSTRACT FROM AUTHOR]

The separation of uranium U(VI) through photoreduction approach has attracted substantial attention. Sulfide-based materials have revealed excellent performance for reducing U(VI) and there is no record of CuS based materials. Herein, we synthesized CuS/TNTAs heterostructured nanocomposites (CUTN) with varied CuS contents via successive ionic layer adsorption and reaction (SILAR) method. After SILAR deposition for 10 times, CUTN-10 showed the best photocatalytic performance, and 92.6 ​% of U(VI) can be removed within 180 ​min. The CuS could provide sufficient photoelectrons and TNTAs can transport these photoelectrons to the adsorbed U(VI) on its surface, the reduced uranium sediment was proved to be (UO 2) O 2 ·2H 2 O. More important, the combination of TNTAs could effective inhibit photocorrosion of CuS and the leaching of Cu2+ was relatively low. We also unconsciously found that CUTN-10 can photoreduce U(VI) without any sacrificial agent which caused by the oxidation of S2−. This work expands the application of sulfide-based materials and provides basic data for bracing the expansion of sulfide-based materials in the field of U(VI) photoreduction. The CUTN-10 exhibited excellent photocatalytic reduction activity for U(VI) in the air atmosphere. The light absorption region could be expanded, and the recombination of charges could be effectively suppressed by combining with CuS. In addition, methanol and S2− consumed holes to separate photogenerated electron-hole pairs, the reduction products were confirmed as (UO 2) O 2 ·2H 2 O species, which activated by both photoinduced electrons and •O 2 − radicals. [Display omitted] ● CUN-10 exhibited excellent photocatalytic reduction activity for U(VI). ● TNTAs can effectively inhibit the photocorrosion of CuS. ● CUN-10 could photoreduce U(VI) without adding sacrificial agent. ● The photo-reduced sediments were confirmed to (UO 2) O 2 ·2H 2 O species. [ABSTRACT FROM AUTHOR]

• A novel CuS-based photocatalytic composite paper is prepared. • The load of reduced graphene oxide on fibers relies on hyperbranched polyamide-amine. • Hyperbranched polyamide-amine grafted on fibers induces uniform growth of CuS. • Reduced graphene oxide inhibits the recombination of photogenerated carriers in CuS. • The composite paper exhibited high photocatalytic activity and good reusability. The use of semiconductor-based photocatalysts to degrade organic dyes in water is receiving more and more attention. However, there are still some problems in practical applications, such as high photogenerated carrier recombination rate, difficulty in recovery, and poor reusability. In this study, reduced graphene oxide (rGO)/copper sulfide (CuS) was loaded onto a dialdehyde cellulose fiber (DACF) with the help of hyperbranched polyamide-amine (HPAMAM) to construct a photocatalytic composite paper (DACF/HPAMAM/rGO/CuS paper). Based on the results, HPAMAM was bonded to DACF and rGO via C N and amide bond, and it could act as a nanoreactor to induce uniform and stable growth of CuS. The photocatalytic activity of the as-prepared DACF/HPAMAM/rGO/CuS paper in the degradation of rhodamine B was about 2.7 times that of the composite paper without HPAMAM and rGO (DACF/CuS paper). Such a high performance could be attributed to the improved charge separation efficiency and the stable composite structure of rGO/CuS in the composite paper. DACF/HPAMAM/rGO/CuS paper was also able to demonstrate excellent stability and reusability, which makes it a promising photocatalyst. This work provides a novel strategy for preparing highly efficient and stable photocatalytic composite paper for degradation of organic dyes. [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]

• High H 2 production activity of dendritic PbS and PbS@CuS was reported for the first time. • Interfacial charge transfer of PbS@CuS were monitored by in-situ X-ray absorption. • Cu L3-edge NEXAFS spectra revealed the transfer of photogenerated electrons from CuS to PbS. • Amounts of CuS are optimized to achieve a max H 2 production rate of 1736 μmol h−1 g−1. Dendritic PbS@CuS core-shell photocatalysts were synthesized with a two-step method: a dendritic PbS core was formed with an ionic liquid/surfactant-assisted hydrothermal method; a CuS shell was grown with an ion-exchange method. Highly active production of H 2 with these dendritic PbS@CuS photocatalysts is reported for the first time. The surface chemistry, morphology, and properties of the crystal lattice of these core-shell nanomaterials were investigated. The effects of the content of the copper (II) nitrate precursor in the nanomaterials on the charge separation, optical properties, and activity for the production of H 2 were investigated. The interfacial charge-transfer behaviors of the composite nanomaterials were studied with Cu L 3 -edge near-edge X-ray-absorption fine-structure (NEXAFS) spectra in situ. A mechanism is proposed based on the results of NEXAFS spectra monitored in situ before and after exposure to solar light. The photoelectron was transferred from CuS to PbS. The proportions of the CuS shells in these dendritic PbS@CuS photocatalysts were optimized to achieve a maximum activity 1736 μmol h−1 g−1 of hydrogen production. [ABSTRACT FROM AUTHOR]

• A simple chemical transformation route for hierarchical CuS microspheres is demonstrated. • The spheres have a unique morphology composed of hierarchical nanosheets. • The change in the morphologies and phase is systematically investigated. • The nucleation and growth mechanism is proposed. • The CuS microspheres show a remarkable 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 TiO 2 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. [ABSTRACT FROM AUTHOR]

• Facile solvothermal route for synthesis of 3D hierarchical CuS architectures consisting of 1D nanotubes. • Green-friendly methodology to tune the Cu(MAA) 2 precursor morphology from hollow micro flower to hexagon stars. • Visible light active photocatalysts with remarkable performance towards the degradation of RhB. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]