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Galena is frequently found in association with other sulphide minerals such as sphalerite and pyrite. The pyrometallurgical methods, is commonly used for zinc recovery and requires high temperatures, resulting in heavy metal pollution and SO2, making it unsuitable for the environment. In this study, the use of H2SO4 without an oxidant for direct leaching of sphalerite concentrate was investigated. The sphalerite concentrate (200 mesh) was roasted for 3 hours at 700°Cto reduce the sulphur content in the sample. Following that, leaching was performed using a sulfuric acid solution with a concentration range of 1-6mol/L for 1-5 hours. The zinc levels in the leached solution were determined using XRF (X-RayFluorescence) and SEM (Scanning Electron Microscopy). Before the leaching process, the particles of zinc sulphide concentrate have a clear surface and are roughly the same shape and size. The micrographs of the leaching residues show a progressive increase in the roughness of the solid as well as an increase in the amount of elemental sulphur covering theparticle surfaces after the leaching process. The presence of sulfuric acid is clearly important in the leaching process, as zinc extraction rate increased with increasing sulfuric acid concentration, but only up to 3 mol/L. The highest zinc extraction, 99.17%, was obtained at 2 mol/L H2SO4 after 3 hours. [ABSTRACT FROM AUTHOR]

We have developed the use of the green approach as technique in the presence of plant-assisted zinc sulphide nanoparticles derived from the euphorbiaceous family. A catalyst is described as an ecologically safe and effective method for producing benzimidazole derivatives. Aromatic aldehyde condensed with the Orthophenyl diamine was followed by a Cyclisation process, which resulted in process of the synthesis of the matching benzimidazole up to 93-95 percent yields. This approach might be used to make benzothiazole and benzoxazoles derivatives as well. [ABSTRACT FROM AUTHOR]

CdSe-based hybrid CdSe/ZnS quantum dots were synthesized. Their optical properties have been characterized using the absorption and luminescence spectroscopy methods. When ZnS shell was grown on the surface shell of CdSe nanoparticles, the photoluminescence stability and shelf life of the quantum dots increased significantly. The energy of the outer shell has increased. Absorption and luminescence spectra shifted to a shorter wavelength range. The size of the nucleus decreased from 3.7 nm to 2.8 nm. The surface was stabilized with oleic acid as an active ligand. After stabilization with the surfactant, the average total hydrodynamic size of the nanoparticles increased. The optical properties of composites of CdSe/ZnS and Cu:CdS/ZnS hybrid quantum dots (QDs) with optically active polymers poly(N-vinylcarbazole) and poly(9,9-di-n-octylfluorenyl-2,7-diyl). The components were mixed in a matrix of an optically transparent PMMA polymer, the mass fraction of which in the composite was 90%. [ABSTRACT FROM AUTHOR]

Over the last two centuries, new approaches to the synthesis of heterocycles have had a profound effect on organic and inorganic chemistry. Nanocatalysts play a significant role in the various filled of science. We present a unique and environmentally friendly method for the one-pot biosynthesis of zinc sulfide nanoparticlesin this research. XRD, FT-IR, EDX, TEM, and investigations described very stable and hexagonal phase ZnS. Nanoparticles are made from leaves extracted from BurmanniaCoelestis tender pods. The current approach for producing ZnS NPs is both efficient and cost-effective. The powder XRD pattern revealed that ZnS NPs formed a hexagonal tight packing configuration with an average crystallite size of 35.6 nm. Simple-shaped ZnS NPs with an average diameter of 60-80 nm are visible in the TEM image. The as-prepared ZnSNPs are good sonocatalysts for the degradation of organic dyes and the production of 2-benzimidazole derivatives. [ABSTRACT FROM AUTHOR]

A preliminary extended x-ray absorption fine structure (EXAFS) investigation of the Zn K-edge in Mn2+-doped ZnS nanoparticles (sphalerite structure) was performed to understand the influence of the doping on the average Zn local environment. Zinc sulfide nanoparticles were synthesized by the chemical co-precipitation method and then doped with Mn at three concentrations 0.5, 0.7 and 0.9 mol. EXAFS data were collected from the synthesized samples at the Zn K-edge to extract information related to the coordination number, bond distance and Debye-Waller factor. EXAFS results of undoped and doped ZnS nanoparticles revealed that doping with Mn did not influence the first neighbor Zn-S bond length and only slightly affected the Zn-Zn bond of the second shell. A decrease in the Debye-Waller factor with an increase in the Mn doping concentration was observed. The results suggest that the Mn cations might substitute Zn in the ZnS lattice during the doping process. [ABSTRACT FROM AUTHOR]

Diamond simulators with specified spectral-kinetic characteristics, modeled by luminophores based on zinc and cadmium chalcogenides, have been developed. It is shown that the luminophores FK-110, R-530, FK-1, FK-2, E-515-115, FL-530 have values of spectral and kinetic characteristics that lie in the region of positive diagnostics (detection) at the used separator settings when using dynamic mode. The use of simulators with specified spectral-kinetic characteristics provides experimental verification and selection of modes for preparing diamonds for the X-ray luminescent separation process. Studies carried out on the «Polyus-M» separator using composite and plastic simulators in dynamic mode showed that the spectral-kinetic characteristics closest to natural diamonds are zinc and cadmium sulfides activated by copper and silver ions. The use of simulators using E-515-115 and FK-110 provides a stable reproduction of the spectral and kinetic characteristics of various types of natural diamonds and allows you to select additional recovery modes in existing X-ray luminescent separation of diamond-containing material. [ABSTRACT FROM AUTHOR]

Nonlinear self-compression of few-cycle multi-mJ pulses at 4.9 µm in ZnS is presented. 80 fs input pulses are compressed to 37 fs with 2.1 mJ energy at a 1 kHz repetition rate. © 2024 The Author(s) [ABSTRACT FROM AUTHOR]

Chemical spray pyrolysis (CSP) was employed to create nanostructured Zinc Sulfide (ZnS) thin films with varying doping levels at 340oC substrate temperature. The impact of sulfur (Ag) concentration on the structural, topographical, and optical properties of ZnS thin films were examined For pure ZnS and ZnS: Ag films, the energy gap was reduced from 3.48 eV to 3.38 eV and it was discovered to have a red change in it as a result of Ag doping. AFM reveals that after Ag doping, the average surface roughness of these films decreases from 6.87nm to 3.19nm. The structural properties show that pure and ZnS:Ag have a cubic shape with an average crystallite size of 10.65–12.05 nm. [ABSTRACT FROM AUTHOR]

An affordable solid state reaction technique was used to make pure and Ni doped ZnS nanoparticles. FTIR, UV–Vis, XRD and SEM were used to characterise the products' functional, Structural and morphological properties. The polycrystalline nature of the nanoparticles with cubic crystal structure was confirmed by X-ray diffraction. FTIR spectroscopy was used to analyse the functional group linked with a molecule's vibration. The photocatalytic activity results showed that Ni doping increased ZnS's photocatalytic activity. As a result, Ni-ZnS could be employed as a photocatalyst to degrade the environmental contaminant Methyl red dye. Among nanocomposites, ZnS have the highest photoactivity. To optimise the photodegradation process of dyes, the influence of sample pH and ZnS dosage were changed. With a concentration of 50 mg/l, Efficient degradation was obtained for Methyl red. In samples with a pH of 6-10, the ZnS indicates the stability. [ABSTRACT FROM AUTHOR]

This work focused mainly on the synthesis and characterization of zinc sulfide nanocrystals using chemical co-precipitation approach. Zinc sulfide nanoparticles with quasi-spherical shape have been fabricated by controlling the concentration of the starting materials, reaction time and PH of the solution. The formation of zinc sulfide nanocrystals was confirmed through TEM, FE-SEM, XRD and EDS techniques. The band gap energy was measured from the UV-Visible spectrum and was found to be 3.8 eV, the observation of red shift with respect to the bulk ZnS is attributed to the effect of quantum confinement. The influences of ZnS nanoparticles concentration and the contact time on cationic dye adsorption, were investigated. The adsorption behavior of ZnS nanoparticles was demonstrated and it was found that ZnS particles have the ability to adsorb methylene blue dye (MB) from aqueous solution. It was found that with increasing amount of ZnS in the dye solution, the removing for MB increased. Moreover, enhancing in the time of shaking causing growing in the absorption of MB on the ZnS. [ABSTRACT FROM AUTHOR]

Convenient and environmental friendly Synthesis of ZnS nanocomposites were carried out by hydrothermal method in Hydrogen Evolution Reaction. Zinc acetate (Zn(CH3COO)2•2H2O) and Sodium Sulphide Nano hydrate (Na2S•9H2O) is used as material. Cobalt (II) Sulfide can be employed as a catalytic material for HER. ZnS is characterized by X-ray Powder Diffraction,HR Scanning Electron Microscopy, Fourier-transform Infrared Spectroscopy and Ultra visible Spectroscopy. The formation of ZnS is can easy charge transfer. The result layout that ZnS - 5% exhibits the best performance of Hydrogen Evolution and it easily release the hydrogen gas separately. [ABSTRACT FROM AUTHOR]

The work gives the results of mathematical modeling of processes that lie in the basis of the operation of electroluminescent light sources (ELLS) based on powdered zinc sulfide electroluminophores excited by alternating voltage. The propagation of light fluxes in phosphor-dielectric layers is considered depending on their thickness and the volumetric ratio of phosphor — binder, and the absence of an extremum depending on the brightness of the layer thickness is substantiated. It is shown that in case of flexible ELLS based on wire-electrodes, the electric field near the wires turns out to be significantly inhomogeneous, which leads to uneven illumination and unequal rate of phosphor degradation in different regions of the light-emitting layer. It is shown that a change in the design of ELLS together with the use of a rotating electric field to excite the glow, makes it possible to significantly increase the brightness and service life of such emitters. The results of the calculations are confirmed by the data of the experiments. [ABSTRACT FROM AUTHOR]

Pure ZnS and Co-doped ZnS thin films were grown using Chemical Spray Pyrolysis (CSP)Technique, and the concentration of the Co doping level (1% and 3%). The hexagonal crystal structure was present in all of the films as shown by X-ray diffraction (XRD) structure of all films. Atomic Force Microscopy (AFM) revealed that film surface was homogeneous. Optical properties of undoped ZnS and the optical bandgap energy (Eg) of Co doped indicated a reduction with Co doping level (1% and 3%). The root of ferromagnetic order at low temperatures (5 K and 100 K) could be traced back to point defects like, zinc interstitials, sulfide vacancies, and zinc vacancies as well as the grain-boundary impact. [ABSTRACT FROM AUTHOR]

Zinc sulfide (ZnS) nanostructure thin films were deposited on bare soda-lime glass substrates utilizing the technique of chemical bath deposition (CBD) at 65±2˚C then annealed at various temperatures in the air. The effect of post-annealing on growth, structure, morphology, and optical properties was investigated by using X-ray diffraction, Field Emission Scanning Electron Microscope (FESEM), and UV-Visible spectrophotometer respectively. XRD analyses confirm the wurtzite hexagonal structure of the ZnS films. Raising the annealing temperature results in a clear change in the morphology of the prepared ZnS thin films. The flower-Like structure for the as-deposited thin film at 65˚C changed to the sheet-like structure at 200˚C then to a cluster and compact aggregation of particles at 400˚C. The transmission of the films reduced from 43% to about only 10% in the range of 300-1200 nm when the annealing temperature increased. Accordingly, the energy bandgap (Eg) reduced from 3.96eV to 3.68eV for the as-deposited and annealed films at 400oC respectively. Controlling the quality of the prepared ZnS thin films will have a wide potential optoelectronic application. [ABSTRACT FROM AUTHOR]

Zinc sulphide was produced on glass substrates using a nebulizer spray pyrolysis process at various deposition temperatures in this study. The temperature for zinc sulphide thin films was set to 250°C. To further understand the structural and morphological behaviour of the produced samples, X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy were used to characterize them. UV-VIS and Four Probe Technique were used to test the materials' optical and electrical properties. [ABSTRACT FROM AUTHOR]

Nanotechnology is one of the important technologies in recent years, which leads to great improvements in many areas of application, whether in the fields of electronics, medicine, physics and chemistry. Thin films of zinc sulfide nanoparticles were deposited onto glass substrates by thermal evaporation from crystals of ZnS NPs. The change in the morphological and structural properties of the membranes deposited in different substrates (100-200 and 300 ° C) was investigated by XRD, SEM, and AFM. The results obtained from XRD showed that the membranes are structured in a cubic zinc mixture with (111) preferential orientation. The size of the nanoparticles ranges from (8-22) nm through the study of FESEM. Also, by examining EDX, the main elements of the compound and the atomic and weight ratios were identified. AFM showed that the surface roughness increases with increasing temperature. The strong cubic structure taken as thin layers allowed us to conclude that ZnS NPs can be used as solar cells. [ABSTRACT FROM AUTHOR]

ZnS nanoparticles were synthesized by co-precipitation method using different capping agents used EDTA (ethylenediaminetetraacetic acid) and PVP (polyvinylpyrrolidone). Field emission Scan Electron Microscope (FE-SEM) with Energy-Dispersive X-ray spectroscopy (EDX), X-Ray Diffraction (XRD), Atomic Force Microscope (AFM), Fourier Transform Tnfrared spectra were used to examine the structural properties and the elemental of the synthesized nanoparticles. UV-optical spectroscopy was used for determination of the optical band gap and the obtained values between 3.4-3.2eV have been found. Average Crystallite Size of nanoparticles measured between 3.7-3.6 nm from XRD pattern. The particle size of nanoparticles were also determined by the capping agent's quality. [ABSTRACT FROM AUTHOR]

The combination of semiconductor quantum dots and liquid-crystalline polymers makes it possible to prepare effective optoelectronic materials with adjustable properties. In this work the density functional theory was applied for the quantum-chemical study of the structure and lowest singlet and triplet excited states of some liquid-crystalline polymers. Intermolecular energy transfer pathways between excited levels of polymers and semiconductor CdS/ZnS core/shell quantum dots were identified. The periodic plane-wave density functional theory study of interactions of monomers with the surface of CdS/ZnS revealed the influence of polymers functional groups on the binding energy with the highest value for nitrile groups. Polymers exhibited compressive stress during their coordination on the surface and formed donor-acceptor bonds with surface atoms of zinc. Differences in geometrical parameters of monolayers in the quantum dots core and shell indicated a deviation of the surface structure from the core and bulk material. It has been shown that liquid-crystalline polymers can act as surface agents for core/shell quantum dots and stabilize their physicochemical properties, surface structure, size and shape. [ABSTRACT FROM AUTHOR]

The degradation of organic dyes using semiconductor nanoparticles (NPS) has been a hot topic of research in the research field for decades. Materials bandgap, crystallinity, stability, high surface to volume ratio, etc., are the factors affecting the dye degradation mechanism. A high surface area will create more active sites, which will increase the reaction speed during the degradation process. In this work, co-metal substituted ZnS (Znx(MnCo)0.5(1-x)S), and CoFe - ZnS composites were used as catalysts for the photodegradation process since the ZnS is a wide bandgap semiconductor material with the most negligible toxicity and high surface to volume ratio. Here authors studied structural and optical characterization of the synthesized material followed by dye degradation analysis using a UV-Vis spectrophotometer. Mainly Methylene blue, Rhodamine-B, and Sunset yellow dyes were used for the study, and the same was irradiated in visible light with the help of an as-prepared catalyst. Finally, the degradation rate of all three dyes was determined and compared. [ABSTRACT FROM AUTHOR]

Zinc sulfide pressure leaching in sulfuric acid is associated with elemental sulfur formation, which melts at temperatures higher 113 oC and covers sulfide minerals surface. Addition of surfactants to leaching pulp decreases minerals wetting by molten sulfur. This paper represents results of zinc sulfide concentrate pressure leaching in presence of sodium dodecyl sulfate (SDS). The leaching experiments indicated that SDS inhibits zinc sulfide dissolution in the first 20–80 minutes at low SDS concentrations (0.2, 0.4 g L−1) and temperatures (120, 130 oC). In spite of this delay total zinc extraction was the same as without SDS addition. At CSDS=0.6 g L−1 zinc extraction was 12 % greater than in absence of the surfactant. In presence of SDS the leaching mechanism changed from diffusion to chemical mode. [ABSTRACT FROM AUTHOR]

In this paper, we report, synthesis of Zinc Sulphide (ZnS) Quantum Dots and its properties which were assessed through various characterization methods. Sol-Gel method using Zinc Nitrate and Sodium Sulphide was used to synthesizeZnS Quantum Dots. X-ray diffraction (XRD was used to assess the optical properties of ZnS Quantum Dots and UV-VIS spectroscopy confirmed the formation of cubic Zinc-Blende structure of ZnS which hada particle size of 1.74 nm. The bandgap of ZnS nanoparticles was determined using UV-VIS optical spectroscopy study, and it presented as a blue shift with respect to the bulk value indicating a strong quantum confinement effect. The antimicrobial activity was studied against Pseudomonas aeruginosa, and the results showed that the prepared nanoparticle exhibits good bactericidal activity. [ABSTRACT FROM AUTHOR]

Recently, transition metal sulphides, in particular ZnS have been intensively studied because of its unique Catalytic functions. These studies have revealed that ZnS nanocrystal are good photo catalysts due to rapid generation of electron –hole pair by photo-excitation. By adding surfactant in synthesis of ZnS, it has been observed that there is phase transition occurs from cubic to wurtzite. In the present work, ZnS is prepared by hydrothermal process using Ethylene diamine as surfactant.Prepared sample were characterized by X-ray diffractions (XRD), XPS, UV/VIS spectra were recorded for evaluation of photo physical properties. The photo activity of prepared ZnS with surfactant was accessed by photo catalytic decomposition of industrial waste under UV irradiation. Under the same condition photocatalytic activity of ZnS without surfactant was also examined. The ZnS with surfactant shows higher catalytic activity compare to ZnS without surfactant. [ABSTRACT FROM AUTHOR]

The synthesis of Fe3O4@ZnS core-shell has been successfully carried out using sonochemical methods. This research was conducted to investigate the crystal structure, functional groups, morphology, and antibacterial activity of Fe3O4@ZnS core-shell by varying the concentration of the ZnS precursor. The XRD characterization results showed that the addition of the ZnS composition resulted in a diffraction peak, representing the inverse cubic spinel (Fe3O4), and cubic sphalerite (ZnS) phases. Based on XRD data analysis, the average particle size of Fe3O4 was 7 - 21 nm, while the ZnS was 3 - 6 nm. The results of FTIR characterization indicated the presence of Fe-O functional groups in the wavenumbers range of 520.24 - 647.36 cm−1 for tetrahedra and 415.83 cm-1 for octahedral, linear to the cubic structure of Fe3O4. In addition, a ZnS functional group appeared at wave number of 959.09 - 1120.25 cm−1 and zinc acetate at wave number of 1548.51 - 1575.79 cm-1. The particle size distribution resulting from SEM characterization for Fe3O4 and Fe3O4@ZnS core-shell with variations of ZnS precursor concentrations of 1x and 2x were 88.36, 105.27, and 156.55 nm, respectively. The antibacterial inhibition of Fe3O4@ZnS core-shell was quite effective in preventing bacterial growth. The diameter of the antibacterial inhibitory capacity of Fe3O4@ZnS core-shell ranged from 3.6 - 7 mm. Thus, Fe3O4@ZnS core-shell is very potential to be applied as an antibacterial agent. [ABSTRACT FROM AUTHOR]

Fine metallic fragments in the millimeter and submillimeter size ranges may result from high-velocity impact with an obstacle or from explosive dispersal of particles. The size, velocity, and spatial distribution of the fine fast-flying particles are difficult to determine with available diagnostic systems. A novel particle impact detector based on a high-sensitivity tribolumi- nescent (TL) screen that is described in this paper can, in principle, fill this niche. The light-generating impact screen utilizes a TL manganese-doped zinc sulfide (ZnS:Mn) powder. The polycrystalline bulk TL material is synthesized in-house using the self-propagating high-temperature synthesis (SHS) reaction between sulfur and zinc. The multilayered sensor screen is comprised of aluminum foil, a layer of coarse polycrystalline particles, and transparent plastic backing. The sensor is optically coupled to a photomultiplier via a fiber optic taper. The operation of the system is demonstrated by impacting the screen with particles in the 0.1–0.6 mm size range accelerated by a helium-driven light-gas gun to speeds in the 0.3–0.8 kms−1 range. The sensor is shown to resolve particle impacts even in dense flows, allowing correlation of the signal amplitude with particle kinetic energy, and can resolve the bow shock as a precursor signature prior to particle impact. [ABSTRACT FROM AUTHOR]

Ternary transition metal sulfides are propitious electrode materials caused by low electronegativity, high conductivity and higher electrochemical activity in comparison to transition metal oxides and single metal sulfides. In this work, Zinc Cobalt Sulfide (ZCS)nanosheets have been successfully prepared through a simple, cost-effective hydrothermal method and characterized by X- Ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM) with Energy Dispersive X- Ray Analysis (EDX), Transmission Electron Microscope (TEM), and X-Ray Photoelectron Spectroscopy (XPS). The supercapacitor performance of ZCS nanomaterial electrodes was done by electrochemical measurements and ZCS nanosheets revealed a clear enhancement in specific capacity and cycling stability. Electrochemical impedance spectroscopy showed a much lower charge transfer resistance of the samples. These results proved that the ZCS nanosheets may be utilized as capable electrode materials for next generation energy storage devices. [ABSTRACT FROM AUTHOR]

In the present work, ZnS/Graphene nanocomposite is prepared by solution mixing and sonication method. The thin films are prepared with homemade chemical spray pyrolysis system (CSP) by the colloidal spray coating method. ZnS/graphene nanocomposite thin film fabricated at the substrate temperature of 350°C. Uniform, adherent, highly crystalline, and transparent thin film obtained. The films characterised by UV-Visible spectroscopy, Photoluminescence, X-Ray diffraction (XRD), Energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). The absorption spectrum of composite shows the blue shift in the absorption peak as compared to intrinsic ZnS thin film. The bandgap increased from 4.1eV (intrinsic ZnS at substrate temperature 350°C) to 4.9eV (ZnS/graphene composite at substrate temperature 350°C). The XRD and EDS analysis confirm the composite formation and purity of the samples. The SEM images show the uniformity of thin films with granules agglomerated structures. [ABSTRACT FROM AUTHOR]

In this work, the impact of various concentrations of dopant ion on the structural and optical properties of manganese doped ZnS Quantum Dots (MnZnS QDs) in presence of a capping agent has been investigated. MnZnS QDs with various concentration of manganese were prepared by chemical precipitation method using thiourea as the capping agent. The prepared Quantum Dots were characterized by various techniques like X-ray diffraction spectroscopy (XRD), UV-vis. spectroscopy, FT-IR spectroscopy, Diffuse reflectance spectroscopy (DRS) and Fluorescence spectroscopy (PL). The results revealed that the size and optical properties of MnZnS QDs varied by dopant ion concentration. FT-IR and PL results confirmed the incorporation of manganese into ZnS crystal structure, and XRD results showed that MnZnS nanoparticles crystallized in a zinc blende structure.PL intensity of thiourea capped MnZnS QDs (TH- MnZnS QDs) were compared, and TH-MnZnS QD-3 (Mn- 1mmol) was found to have the highest PL intensity. The band gap values decrease with increase in concentration of dopant. [ABSTRACT FROM AUTHOR]

In the present work, studies have been carried out on the structural and morphological properties of kesterite Copper Zinc Tin Sulphide (CZTS) thin films deposited on Molybdenum (Mo) foils. The effect of oxygen content in CZTS processed at various sulphurization temperatures i.e. 550 °C to 700 °C is studied. Structural properties of these samples are evaluated by using X-ray diffraction (XRD), crystalline quality decreases with the increase of oxygen level (∼ 52 % atomic weight percentage) at 550 °C and 700 °C sulphurization temperatures. Phase formation of CZTS and existence of secondary phases are further confirmed by Raman spectroscopy. Formation of nanorods with higher oxygen level at 550 °C and 700 °C are observed. The atomic percentages of Zn/Sn, S/metal, Cu/(Zn+Sn) are also dependent on sulphurization temperatures and the oxygen atomic weight percentages. [ABSTRACT FROM AUTHOR]

In the present work, we have synthesized the high quality Zinc Sulphide thin films using a facile, inexpensive and versatile chromatography sprayer (CS) for the first time. CS is an atomizer made of borosilicate glass which produces pulverized mist spray of colloidal solution. It is used as spray nozzle of our home made spray pyrolysis system. In CS, solution and nozzle are one system and connected by glass capillary. Zinc Sulphide nanoparticles are synthesized by hydrothermal method using low cost precursors under optimized synthetic conditions. The thin films are prepared using our homemade spray coating system under optimized spray rate by colloidal spray coating method. Effect of substrate temperature on X-ray diffraction (XRD) spectra, Surface Electron Microscopy (SEM) images, UV-Visible absorption and photoluminescence of ZnS thin films is studied. Colloidal spray coating of ZnS is found to form uniform, adherent and transparent ZnS films. The XRD analysis shows the polycrystalline and cubic nature of film material and confirms purity of material while having no secondary phase. The colloidal spray coated films are highly transparent due to suppression of coffee ring effect as compared to conventional precursor coating solution. [ABSTRACT FROM AUTHOR]

Deposition parameters play a vital role in deposition of various thin films. Present paper concentrating concentration of precursor, Volume of the precursor, spray rate, nozzle to substrate distance and carrier gas pressure to synthesize the lead sulphide thin films which will be preliminary study for the synthesis of lead zinc sulphide thin films. [ABSTRACT FROM AUTHOR]

In the recent years, rare-earth free (REF) nanoscale phosphors have become a crucial basis in conventional lighting and display applications due to their low cost and availability. To explore the performance of such REF phosphors beyond its conventional applications in this work we have synthesised highly luminescent cubic phase zinc sulphide (ZnS) nanosphere via a facile, rapid and energy efficient microwave synthesis route and effectively applied for several exotic applications. Under 350 nm UV excitation, the synthesized nanophosphor exhibits intense green emission around 550 nm. The homogeneous spherical structure of the nanophosphor, with an average particle size of 20 nm, increases emission efficiency and leads to durable green emission. The obtained nanophosphor offers new opportunities for visualizing latent fingerprints (LFPs) on different surfaces via powder dusting technique. We further successfully demonstrate a high-performance security ink using this REF nanophosphorto prevent counterfeiting. [ABSTRACT FROM AUTHOR]

We have carried out structural and elastic propertiesof Gallium Phosphide (GaP) semiconducting compound. For this Purpose, we used effective inter-ionic potential method, which consist of the long-range Coulomb and van der Waals (vdW) interactions and the short-range repulsive interaction of up to second-neighbor ions within the Hafemeister and Flygare approach. First, we used the Slater-Kirkwood variational method to estimate the vdW coefficients. The estimated value of the phase transition pressure (Pt) is 26GPa for B3(ZnS) type phase structure to B1(NaCl) type phase structure, which is agreeing with the experimental and theoretical reported data. We have also predicted the elastic properties of GaP compound within the effective inter-ionic potential approach. [ABSTRACT FROM AUTHOR]

In the present work ZnS-CdS core-shell-type composite nanostructures was prepared by hydrothermal method. The prepared samples were characterized by X-ray diffraction (XRD) for structural confirmation. Microstructural study by scanning electron microscopy (SEM) exhibit nanoscale dimensions of as-synthesized composite. UV/VIS spectra were recorded for evaluation of photophysical properties. The composite was explored as photocatalysts to study dye degradation using methylene blue in aqueous slurry under irradiation of 663 nm wavelength and congo red under irradiation of 493 nm wavelength. Under the same conditions the photocatalytic activity of the individual phases ZnS and CdS were also examined, just for sake of comparison. The ZnS-CdS composite is found to be enhancing the rate of photo degradation of toxic dyes in presence of visible light as compared to ZnS and CdS individual phases. Thus ZnS based metal sulphide/oxide semiconductor nanocomposites are potential material for Photo-degradation of toxic dyes, and act as good photocatalyst . [ABSTRACT FROM AUTHOR]

undoped and Mn-doped zinc sulfide thin films were prepared on glass substrate by spray pyrolysis technique (SPT). XRD, AFM and UV–visible spectra measurements were done to explore the effect of doping on structural and optical properties of ZnS films. X-ray diffraction illustrates polycrystalline nature of the films increases via increasing Mn doping. Crystallite size evaluated by Scherrer’s formula shows increasing with increasing doping. Average diameter for undoped ZnS is 84·78 nm and it increases to 96·93 nm for 3%Mn-doped ZnS. As Mn doping concentration increases optical band gap of films decreases [ABSTRACT FROM AUTHOR]

In the world practice, lead-zinc karst deposits occupy one of the leading positions in terms of reserves and rich ore mining. In terms of metal content, they excel all other commercial-genetic types. Karst deposits are a new commercial-genetic type for Kazakhstan. One of the promising regions for discovery of the karst deposits is the Great Karatau, known for such objects (Achisai, Karasai, Kantegi, Araltau and oth.). The area of the Achisai ore cluster is composed of thick carbonate strata of limestones and dolomites of various ages, with water-resistant horizons of marls, siltstones, and mudstones. Lead-zinc mineralization is confined exclusively to limestones and dolomites, relatively chemically pure, with a small amount of impurities of terrigenous material. The paper considers the local search attributes of lead and zinc karst mineralisation: lead and zinc sulphide mineralisation, mineralised karst, limonized rocks with mineralisation, lithological and chemical composition of rocks, metasomatic changes, geophysical and geochemical search criteria, atmo-chemical criteria, geomorphological features, tectonic breccias, and calcite veins. The above criteria can be used for large-scale forecasting and prospecting, and will allow identifying the most favourable sites to localise the mineralisation. The whole set of direct and indirect signs should be used in forecasting and prospecting works. Each of them, taken separately, cannot serve as a reliable and unambiguous search criterion of karst mineralisation. [ABSTRACT FROM AUTHOR]

6LiF:ZnS(Ag) micro-particle neutron detectors are a promising technology to further improve neutron detection capabilities for a variety of applications. Specifically, we have been investigating 6LiF micro-particles coated with ZnS(Ag) to increase the neutron detection efficiency, light production, and light collection efficiency when compared to the existing powder-based technology (EJ-426 from Eljen Technology). Extensive radiation and light transport simulations with single micro-particles have been performed to find the optimal 6LiF diameter and ZnS(Ag) coating thickness. Full-scale multi-particle simulations also have been performed to determine the optimal pitch (particle-to-particle distance) and detector thickness. Randomizations of 6LiF radius, ZnS(Ag) coating thickness, position of particles, as well as shape of particles and partial coating have been performed to account for possible manufacturing imperfections. EJ-426 sheets have been modeled for reference purposes by defining spherical grains of 6LiF and ZnS(Ag) and compared against experiments. The simulation results show that the coated micro-particles should dramatically increase the neutron detection efficiency, light production, and light collection efficiency when compared to the existing EJ-426 technology. [ABSTRACT FROM AUTHOR]

Biohydrometallurgical technologies are widely used for the extraction of non-ferrous and precious metals from sulfide ores and concentrates including gold-bearing refractory concentrates. Biohydrometallurgical treatment of gold-bearing sulfide concentrates is based on the oxidation of sulfide minerals by acidophilic microorganisms oxidizing ferrous iron and sulfur. This makes it possible to increase gold extraction by subsequent cyanidation as biooxidation results in disruption of crystal lattice of sulfide minerals and gold finely dispersed in these minerals becomes available for dissolving by cyanide. In the present study, the possibility of processing of gold-bearing pyrite-arsenopyrite concentrate containing of 56% of pyrite, 14% of arsenopyrite, and 45.5 g/t of gold by tank biooxidation was studied. Biooxidation in continuous mode was performed at 40°C in laboratory scale reactors using association of acidophilic microorganisms. Residence time was 6 days. Pulp densities (solid to liquid ratio, S : L) were 1.5 : 10 and 1: 10. At pulp density of 1.5 : 10, biooxidation was not stable, probably due to high sulfide minerals content in the concentrate, while oxidation at a pulp density of 1 : 10 was stable, which was indicated by liquid phase parameters (pH, Eh, ferric and ferrous iron concentrations). Thus, biooxidation to obtain solid residue, which was used for further gold extraction was performed at a pulp density of 1 : 10. Biooxidation made it possible to oxidize 63% of pyrite and 95% of arsenopyrite. Gold recovery by cyanidation increased from 57% (from unoxidized concentrate) to 83% (from solid residue of biooxidation). Liquid phase of the pulp containing high concentration of Fe3+ ions (up to 22 g/L) was used for oxidative leaching of substandard copper-zinc concentrates. Three samples of copper-zinc concentrates containing 17 and 2.9%, 16 and 5.3%, and 6.2 and 7.3% of Cu and Zn were studied. Leaching of these concentrate performed at 80°C, pulp density of 1 : 10 for 3 h made it possible partially leach both copper and zinc. Copper content in the solid residues increased or did not change significantly, while zinc content decreased in comparison with the concentrates, as copper sulfide minerals of the concentrates (chalcopyrite and tennantite) are more refractory to oxidative leaching than zinc sulfide (sphalerite). Copper and zinc content in the residues was 17 and 1.45%, 16.7 and 2.9%, and 6.15 and 3.95%. Decrease in zinc content in substandard concentrates, which cannot be successfully conditioned by flotation, using alternative approach including hydrometallurgical methods is promising for the production of high-grade copper concentrates. Thus, in the present study, it was demonstrated that biooxidation of sulfide gold-bearing concentrates may be used not only to increase gold extraction rate, but also to obtain solutions with high Fe3+ content, which can be used for oxidative leaching of other mineral raw materials. [ABSTRACT FROM AUTHOR]

We have presented the numerical results of calculations obtained with the help of a model of the ZnS combustion synthesis in a wet inert gas environment. The model was a modification of the model of the ZnS combustion synthesis on argon developed earlier. The results let us numerically and with the high accuracy estimate separately the heat transfers by both convection, conduction and thermal radiation during the combustion under the conditions stated in the heading. As a result, we are not only able to compare the heat transfers by the convection, conduction and thermal radiation, but also investigate in details the reason of much smaller heat transfer by radiation with respect to convection in the combustion system considered. On one hand, our results agree with data on relative values of heat transfer by convection, conduction and radiation, and on the other hand, they allow us to specify accurately the reason of a smallness of heat transfer by radiation more precisely and reasonably. We have concluded that this is a hot thin cloud of water vapors that is formed in a close vicinity of the igniter, absorbs radiation and prevents the other part of green mixture both from ignition by radiation and the subsequent propagation of the combustion on the basis of radiation heat transfer. In the presented paper a modification of the previous research results was carried out which allows taking into account the influence of water vapor on the radiation heat transfer process during the synthesis of zinc sulfide. At sufficiently high concentration of vapors the model explains the abnormally low values of effective gas permeability coefficients calculated without taking into account the indicated effect. [ABSTRACT FROM AUTHOR]

If humans desire to leave the safety of Earth and explore the universe, cost effective and low mass health monitoring sensors will be essential to monitor the ionizing radiation to ensure the safety of the astronauts. A luminescent material-based sensor could provide a reliable in-situ radiation monitor. Research to date includes irradiating a variety of phosphors with 3 MeV protons and 20 keV electrons. Results have shown that radiation has adverse effects on the luminescence emitted by producing quenching centers. This paper investigates the effects of radiation on large-grained zinc sulfide doped with manganese (ZnS:Mn) as well as two different forms of tetrakis: europium dibenzoylmethide triethylammonium (EuD4TEA) and magnesium dibenzoylmethide triethylammonium (MgD4TEA). In addition, two different binders, i.e., poly (phenyl methyl) siloxane and poly (methyl methacrylate), are also used. This research can be used to help determine if luminescent materials can be used as a sensor to detect ionizing radiation in extreme environments like space. [ABSTRACT FROM AUTHOR]

CuS-ZnS nanocomposite films were synthesized through the interaction of H2S gas with nanostructured Cu-Zn films deposited through vacuum evaporation technique at a relatively high pressure of an inert gas. The film samples were synthesized for four different atom% of Zn. XPS analysis showed that both Cu and Zn existed in the +2 oxidation state in the samples. XRD patterns showed that in the samples, CuS and ZnS existed as separate phases and hence the samples were copper sulphide-zinc sulphide nanocomposite films. Also, HRTEM image and SAED pattern of the sample containing the highest atom% of Zn confirmed the co-existence of both CuS and ZnS phases in the sample. The grain size of CuS which was the major phase in the CuS-ZnS nanocomposite films decreased with increase in the atom% of Zn. Red shift of the Raman modes of CuS phase in the samples was an indication of substitutional doping of Zn into the CuS lattice. Analysis of optical absorption and reflection spectra of the samples indicated the possible application of the films as window layer in solar cells. [ABSTRACT FROM AUTHOR]

The work is devoted to the search for new materials for the detection and monitoring of ammonia as one of the toxic components of the chemical and petrochemical industry. A large-scale work was carried out, based on versatile sensitivity studies of solid solutions semiconductor surface obtained from binary compounds of cadmium telluride and zinc sulphide to ammonia. A correlation between the data obtained was revealed and a sample with a more active surface to the gas adsorbate was proposed as a material for the ammonia sensor. [ABSTRACT FROM AUTHOR]

Optimized thickness of Zinc sulfide thin films are prepared using nebulizer spray pyrolysis technique. The Zinc sulfide thin films were coated onto glass substrate at 450°C by changing volume of concentration as 5ml, 8ml and 10ml X-ray diffraction measurements results shown the films structural properties influence the thickness of film. The films showed band gap ranging from 3.72 to 3.15 eV depending on volume of solution with corresponding thickness. The refractive index from 2.17 to 2.3 is calculated using Tripathy and Herve-Vandamme (HV) Relation for corresponding band gaps. In this experimental work point out that the effect of structural property on the optical properties such as transmission, reflectivity and absorption. Optimized thickness of the ZnS thin film coating is desirable as a anti reflection coating in the solar cell. [ABSTRACT FROM AUTHOR]

Recently, transition metal sulphides, in particular ZnS have been intensively studied because of its unique Catalytic functions. These studies have revealed that ZnSnanocrystal are good photo catalysts due to rapid generation of electron–hole pair by photo-excitation. By adding surfactant in synthesis of ZnS, it has been observed that there is phase transition occurs from cubic to wurtzite. In the present work, ZnS is prepared by hydrothermal process using Ethylene diamine as surfactant. Prepared sample were characterized by X-ray diffractions (XRD), FTIR, UV/VIS spectra were recorded for evaluation of photo physical properties. The photo activity of prepared ZnS with surfactant was accessed by photo catalytic decomposition of industrial waste under UV irradiation. Under the same condition photocatalytic activity of ZnS without surfactant was also examined. The ZnS with surfactant shows higher catalytic activity compare to ZnS without surfactant. [ABSTRACT FROM AUTHOR]

Structural and elastic properties of WN has been investigated using theoretical model calculations. The long range Coulomb, van der Waals (vdW) interaction and the short range repulsive interaction up to second-neighbor ions within the Hafemeister and Flygare approach with modified ionic charge are properly incorporated in effective interionic potential (EIOP) model. We first deduced vdW coefficients with the help of Slater-Kirkwood variational method. A structural phase transition from ambient ZnS (B3)-type structure to NaCl (B1)-type was identified in pressure volume curve in WN compound. The estimated value of transition pressure is 2GPa in WN compound. Further, the variation of second order elastic constants (C11, C12 and C44) were followed the systematic decreasing trends with pressure. [ABSTRACT FROM AUTHOR]

Cadmium zinc sulphide (Cd1-xZnxS), a typical ternary II-VI semiconductor material, has considerable interest owing to their use in the fabrication of heterojunction solar cells and other optoelectronic devices. This work presents the influence of different solvent ratios of Cd and Zn on optical, structural and morphological properties of the prepared Cd1- xZnxS thin films by a simple cost effective chemical Bath Deposition (CBD) technique on glass substrate. Nanocrystalline thin films of Cd1-xZnxS were prepared in an alkaline medium with the molarity of 0.25M at 343K for 90 minutes with varying Cd and Zn solvent ratios. The as deposited films were characterized by UV- Visible spectra, XRD and SEM. The direct optical band gap energies of the as deposited films for different solvent ratios were found in the range of 3.2-4.1 eV. An increase in transmittance and band gap value was found with the increasing Zn concentration into CdS thin films. The XRD studies showed the both hexagonal and cubic phase structure of Cd1-xZnxS thin films and the estimated grain size was 6.63nm. SEM micrographs reveal nearly uniform and homogeneous Cd1-xZnxS films without any pin holes. [ABSTRACT FROM AUTHOR]

This paper presents the effect of ZnS on frictional behaviour of composite friction brake containing graphite as the lubricant. The composite brake specimen containing different composition of lubricant that were 15% graphite (15G), 12% graphite + 3% ZnS (12G3Z), and 9% graphite + 6% ZnS (9G6Z) were manufactured and investigated. Friction testing was performed on the composite specimens using a pin on disc tribometer. The friction testing was conducted by pressing specimen against the surface of the rotating disc. The friction force was measured and recorded by load cell and data acquisition system during testing process for 120 seconds. Parameters of the friction testing were contact pressure and sliding speed was varied. Each variation was tested on two specimens and each specimen was tested three times. The result showed that the coefficient of friction decreased with the increasing sliding speed and increased with the increasing contact pressure. The addition of ZnS into composite friction brake containing graphite could increase the coefficient of friction. The addition of ZnS also increased the specific wear rate and the disc temperature. The critical role of solid lubricants in composites friction brake and related discussions was also studied. [ABSTRACT FROM AUTHOR]

We present the formation of ZnS quantum dots in ethylene-vinyl acetate (EVA) matrix using the thermolysis process of zinc pyrrolidinedithiocarbamate (ZnPDTC). The annealing time and precursor concentration showed no significant effect on the radius of the quantum dots, but there is a significant difference seen on the annealing temperature at 220°C. Quantum confinement effect in semiconductor quantum dots of ZnS has been studied using the Brus Equation. Results showed that ground state confinement energy is inversely proportional to the size (radius) and exhibited a strong quantum confinement. The absorption peak of the obtained quantum dots showed in the range of 310-330 nm, a blue shift compared to that of the ZnS crystal structure. Growth kinetics follows the linear relationship of the third power of the particle size versus the time and a diffusion-limited Ostwald ripening mechanism was involved. [ABSTRACT FROM AUTHOR]

This paper reports on room temperature photoluminescence (PL) studies on copper zinc sulfide (CuZnS) films that are deposited through chemical bath deposition (CBD) technique. The PL emission is a broad emission in greenish red region of the spectra. PL spectroscopy is employed as a non-destructive tool to identify copper rich and copper deficient areas of the film. The emissions attributing to copper related and zinc related defects are well distinguished in copper rich and zinc rich films. PL also serves as a contactless method to determine the uniformity of the films. Structural and morphological analysis of the film gives further confirmation of the results obtained from PL analysis. [ABSTRACT FROM AUTHOR]

The synthesis of undoped ZnS and Cu doped ZnS have been carried out by wet chemical method at room temperature. The as-prepared ZnS and ZnS:Cu nanoparticles are characterized using X-ray diffraction, UV-Vis spectrophotometer and photoluminescence spectroscopy. The size of the synthesized nanoparticles is found to be in 2.5 nm range. The band-gap is found to be higher indicating blue shift compared with that of the bulk ZnS which is attributed to quantum size effect. Room temperature photoluminescence spectrum of the undoped sample exhibits a blue emission peaked at 430 nm whereas Cu doped sample exhibits the blue emission of ZnS and a green emission peaked at 520 nm under the same UV excitation. [ABSTRACT FROM AUTHOR]

Cadmium Zinc Sulphide (Cd: Zn)S thin films were prepared by chemical bath deposition method for different molar concentrations of Cd under the same conditions of temperature, pH and deposition time. Structural, optical and morphological properties of the films were investigated. All the films showed nanocrystallinity with hexagonal structure and the average grain size was found to decrease with increase in Cd concentration. Tunable band gap has been observed with controllable concentration of Cd atoms in to ZnS lattice. The photoluminescence spectra showed broad and asymmetric emission due to the combination of near band edge emission and emission from intrinsic point defects. [ABSTRACT FROM AUTHOR]