Pure Zinc Sulfide Research Articles

Tailoring the Electrochemical Properties of ZnS Electrodes via Cobalt Doping for Improved Supercapacitor Application

AbstractFor practical uses, there has been a lot of interest in simple, inexpensive, and efficient synthesis of materials for supercapacitor applications. Pure and cobalt-doped zinc sulfide (Co-doped ZnS) powder samples were synthesized in this study using a straightforward co-precipitation process, and their electrochemical performance was examined. It was observed that, at a scan rate of 10 mV s−1, pure ZnS has a specific capacitance of only 460.7 F g−1; however, the Co-doping in ZnS increases it to 947.8 F g−1 for the 5% Co-doped sample, Co (0.05): ZnS. The results suggest that Co-doping in ZnS increases the kinetics and rate of redox processes. The increase in electrochemical active sites brought about by integrating Co into ZnS increases the surface area and results in the sample's capacity for storage. The encouraging findings increase the likelihood of elemental doping with other transition metal elements to increase the energy storage capability of earth-abundant ZnS samples.

Supremacy of l-glutamic acid on cerium doped ZnS nanoparticles for enhanced structural, morphological, optical properties and their applications in antimicrobial activity with efficient detection of latent fingerprints

The pure Zinc Sulphide (ZnS) and l-Glutamic acid capped Cerium doped Zinc Sulphide nanoparticles of different concentrations (0, 5, 10 & 15 mol %) was developed via a simple chemical co-precipitation strategy. l-Glutamic acid is the a minimum hazardous, non-essential amino acid group, and its capped properties are optimal for semiconducting nanoparticles that include ZnS. It also has a considerable effect on enhancing the structural, optical, and photoluminescent properties of Ce-doped ZnS nanoparticles. The produced nanoparticles were examined using X-ray diffraction (XRD), dynamic light scattering (DLS), Field emission scanning electron microscope (FESEM), Fourier transform Infrared spectroscopy (FT-IR), Photoluminescence (PL), and UV–Vis spectrometer. The XRD pattern revealed that all of the generated nanostructures have a cubic form with diffraction planes (111), (220), and (311), and the dimensions of the crystallite ranging from 1.685 nm to 2.144 nm. Its morphological view of nanoparticles was investigated utilizing FESEM. DLS testing demonstrated that the particle sizes were less than 30 nm. The functional groups of nanoparticles have been identified using FTIR investigations. PL investigations suggested the existence of substantial emission bands. The ultraviolet–visible scrutiny exhibited an optical band gap that spans 3.12–3.77 eV. The antimicrobial activity analysis was examined by the gram-positive and gram-negative bacteria in pure ZnS, l-glutamic acid-capped ZnS, and glutamic-capped 15 mol% Ce-doped ZnS, with their inhibitory zones also verified. Finally, it was ascertained that this type of nanoparticles was highly effective to reveal the fingerprints detection purposes in forensic applications.

Electrochemical Investigation of ZnS/NiO Nanocomposite based Symmetric Supercapattery

AbstractSupercapattery is an ideal energy storage device combining the features of supercapacitors and batteries, offers a high‐energy density as well as high‐power density with extended operational lifespan. In this work, zinc sulfide (ZnS) and zinc sulfide/nickel oxide (ZnS/NiO) nanocomposite was synthesized via chemical coprecipitation method and characterized using state‐of‐the‐art analytical tools. The ZnS/NiO electrode exhibited remarkable electrochemical performance as an electrode material than pure ZnS. The ZnS/NiO nanocomposite exhibited high crystallinity, and spherical nanoparticles with an average grain size of 20–40 nm having a homogeneous dispersion. The ZnS/NiO electrode exhibited an ultrahigh specific capacity of 1803.87 Cg−1 at a relatively low scan rate of 10 mVs−1 in a 1 M KOH solution from cyclic voltammetry and 393 Cg−1 at 16 Ag−1 from charge discharge measurements, and it showed exceptional cycling stability (98 % capacity retention after 1000 cycles). Furthermore, the ZnS/NiO symmetric supercapattery device exhibited 44.43 Fg−1 specific capacitance, 5.52 Wh kg−1 energy density, and 1600 Wkg−1 power density at current density of 0.8 Ag−1 in 1 M KOH solution from galvanostatic charge discharge. After 3000 cycles, the ZnS/NiO nanomaterial demonstrated promising cyclic stability of 95 %. The ZnS/NiO supercapattery nanocomposite might be considered as a potential hybrid electrode material for the future development of electrochemical energy storage devices.

Effect of Copper Inclusion in Zinc sulfide Thin Films for Photocatalytic Applications

Transparent and well-adhered pure zinc sulfide (ZnS) and different concentrations of copper-doped zinc sulfide thin films were obtained on glass substrates by the Chemical bath deposition process. Zinc acetate, copper acetate and thiourea were employed as sources of Zn2+, Cu2+ and S2- ions, respectively; ammonia and hydrazine hydrate served as complexing agents for the preparation of pure zinc sulfide and different concentrations of copper-doped zinc sulfide thin films. By adjusting the ammonia concentration, the prepared solution pH was maintained at 11. The prepared samples were deposited at the rates of 60 and 90 minutes each, with the bath temperature being held at 80 °C. The structural, morphological and optical properties of the prepared films were characterized by XRD, FE-SEM and EDX, and the results were reported. The XRD patterns revealed that all thin films possess a polycrystalline cubic zinc blended structure and that the prepared pure and copper-doped ZnS thin films have good crystallinity; the crystallite sizes were less than 20 nm. From the FE-SEM spectra, it is understood that the pure and Cu-doped ZnS thin films were uniformly coated with spherical morphology. The surface morphology, optical characteristics and deposition mechanism were all obviously impacted by the ammonia concentration. Additionally, under UV light irradiation, the effect of the photocatalytic property of the prepared thin films with methylene blue dye was studied and the corresponding dye degradation graphs were reported.

Hydrothermally grown pure and Er-doped ZnS nanocrystals based flexible piezoelectric nanogenerator for energy harvesting and sensing applications

Pure zinc sulphide (ZnS) and Er-doped ZnS nanocrystals were grown by hydrothermal method at low temperature. Powder XRD analysis reveals the formation of wurtzite hexagonal phase structure for both pure and Er-doped ZnS samples. Morphology of 2D nanocrystals for both pure and doped ZnS nanocrystals was confirmed by FESEM technique. Presence of Er element in Er-doped ZnS was confirmed by energy-dispersive X-ray spectroscopy. Further, both pure and Er-doped nanocrystals have been used as piezoelectric fillers in polydimethylsiloxane (PDMS) for the fabrication of flexible piezoelectric nanogenerators. The Er-doped ZnS based nanogenerator showed almost 9 times (∼ 36 V) higher open circuit voltage as compared to pure ZnS based nanogenerator (∼ 4 V). Then, Er-doped ZnS nanocrystals based device was used to harvest the mechanical energy under the human walking and running conditions. Also, this device generated significant electrical signal under the human elbow bending. The output performances of Er-doped ZnS based device indicates that it can be a potential candidate for mechanical energy harvesting under various human body motions as well as for wearable piezoelectric sensor applications.

Plectranthus barbatus Leaf Extract-Mediated Synthesis of ZnS and Mg-Doped ZnS NPs: Structural, Optical, Morphological, and Antibacterial Studies

In the current study, the researchers have explored the influence of doped Mg ions on the optical, morphological, and structural properties of zinc sulfide (ZnS) nanoparticles (NPs). The green technique was employed to prepare pure and 2% and 5% Mg-doped ZnS NPs using the Plectranthus barbatus leaf extract as a capping agent. XRD, SEM, FTIR, and UV-visible were used in the investigation process. The XRD results showed that all the synthesized materials have a cubic structure with space group F-43m. The Dav was nearly in the range of 2.02–2.20 nm. The SEM images illustrated that NPs were agglomerated. The UV-visible results showed that the optical bandgap increased as Mg2+ ions increased, which was in the range of 3.81–4.42 eV. The absorption shoulder of the prepared NPs is blue-shifted with increasing dopant concentration. The FTIR spectrum gives characteristic peaks for Zn-S bonds and asserts NPs’ formation. The antibacterial check against E. coli and S. aureus bacterial strains revealed that pure and Mg-doped ZnS NPs have higher activity for both bacterial strains. The results have shown that the prepared materials can be used for antibacterial activities and optoelectronic applications.

The effects of saline water on the recovery of lead and zinc sulfide during froth flotation

In this study, we investigated the effects of water salinity on the flotation performance of pure lead and zinc sulfide mineral samples as well as a Pb/Zn complex sulfide ore by means of micro-flotation and batch flotation experiments. Our results showed higher PbS and ZnS recoveries in more concentrated NaCl salt solutions. The results for the experiments using seawater demonstrated that in the presence of additional ions, such as Ca2+ and Mg2+, the recovery of PbS and ZnS was significantly reduced.As part of this investigation, we developed and implemented a surface complexation model for ZnS based on the presence of two differently charged surface sites. Zeta potential measurements of ZnS particles were used to optimise the parameters of our model. It was found that the surface potentials calculated using this model were in good agreement with the experimental zeta potentials, validating the model for predicting the zeta potential behaviour of ZnS particles over a broad range of pH and NaCl concentrations.Additionally, total interaction free energies were determined as a function of separation distance, representing particle–particle and particle-bubble interactions of our study in different NaCl concentrations. The theoretical analyses showed that asymmetric Pb/Zn particle–particle interactions were repulsive at lower NaCl concentrations, before becoming purely attractive at higher NaCl concentrations. For the case of the symmetric particle–particle interactions, attraction controlled all interactions, regardless of NaCl concentration. The calculated PbS-bubble interactions were repulsive in lower NaCl concentrations but became increasingly attractive in higher NaCl concentrations. Strong repulsions controlled all ZnS-bubble interactions, and these interactions remained repulsive with increasing NaCl concentration. The theoretical projections presented in this study were in good agreement with the measured saline water flotation phenomena.

Effect of metal ion on optical, photoluminescence, morphological, and photocatalytic properties of ZnS nanoparticles.

The semiconducting materials of pure zinc sulfide (ZnS), 2.5 wt%, 5.0 wt%, 7.5 wt%, and 10 wt% of Ag-doped ZnS nanoparticles were prepared using the sol-gel technique. The prepared nanoparticles were analyzed by powder X-ray diffraction (PXRD), Fourier transformed infrared (FTIR), UV-visible absorption, diffuse reflectance photoluminescence (PL), high-resolution transmission electron microscope (HRTEM), and field emission scanning electron microscope (FESEM) to study the properties of pure ZnS and Ag-doped ZnS nanoparticles (NPs). The Ag-doped ZnS nanoparticles have a polycrystalline nature, which is confirmed by PXRD analysis. The functional groups were identified by the FTIR technique. The bandgap values decrease with increasing Ag concentration compared to pure ZnS NPs. The crystal size lies between 12 and 41nm for pure ZnS and Ag-doped ZnS NPs. The presence of Zn, S, and Ag elements was confirmed by EDS analysis. Using methylene blue (MB), the photocatalytic activity of pure ZnS and Ag-doped ZnS NPs was performed. The highest degradation efficiency was observed for 7.5 wt% Ag-doped ZnS NPs.

Synthesis of copper-doped indium zinc sulfide nanosheets for high efficiency photocatalytic hydrogen production

The excessive use of fossil energy has caused a series of environmental problems. Hydrogen is a green energy substitute for fossil energy, and photocatalytic hydrogen production is an effective means of hydrogen production. Indium zinc sulfide catalyst has great application prospect in the field of photocatalysis due to its advantages of high stability and visible light absorption. Based on this, Cu doped indium zinc sulfide nanosheets were prepared in this paper. Compared with pure indium zinc sulfide nanosheets, copper doped indium zinc sulfide nanosheets have better photocatalytic hydrogen production performance. The design and synthesis of photocatalytic hydrogen-producing catalyst has important guiding significance.

Photocatalytic Degradation of Acidic and Basic Dye by ZnS and Tin-Doped ZnS Nanocatalysts

Zinc sulphide (ZnS) nanomaterials were hydrothermally prepared and doped with 2% Tin (Sn). UV–Visible, X-ray Diffraction (XRD), Energy-Dispersive X-ray (EDX), Scanning Electron Microscopy (SEM), Fourier transform Infrared (FTIR) spectroscopy and Thermogravimetric analysis (TGA) were used to characterize the produced NPs. With successful doping, the band gap of ZnS nanomaterials decreased from 3.50 to 3.10 eV. Cubic crystal structure of ZnS and Sn-ZnS nanomaterials was shown by XRD with the average particle size of 16.30 and 18.62 nm, respectively. ZnS nanomaterials were found to have spherical shape, and no change in shape was noticed with Sn-doping. Using TGA analysis, 22.8% and 21.5% weight loss was observed in Zinc sulphide and Tin-doped ZnS nanocatalyst, respectively, at heating range of 40–600 °C revealing their stability to temperature. The synthesized nanoparticles were also used for the photodegradation of Coomassie Brilliant Blue G-250 (CBB G-250) and Basic Blue-3 (BB-3) dyes in aqueous solution. For photodegradation reaction using bare ZnS and Sn-doped ZnS nanomaterials, activation energies of 8.6 kJ/mol and 32.1 kJ/mol were calculated for ZnS and Sn-ZnS NPs, respectively. First-order reaction kinetics was followed by the photodegradation of both the dyes using these NPs. About 84% and 93% degradation was observed for CBB G-250 dye using bare and Sn-doped ZnS NPs at 240 min time interval while using the same nanoparticles for the degradation of BB-3 dye the degradation reached 83% and 95% at 360 min time, respectively. Low concentration (10 ppm) of dyes, maximum dosage (0.03 g) of the catalysts and increasing temperature up to 70 °C favoured the photocatalytic degradation. Per cent degradation of both the dyes was found higher at low pH(3.5). Both bare Zinc sulphide and Sn-doped Zinc sulphide nanomaterials could be recycled for the given dyes detoxification as shown by the recyclability of the used catalysts, but the performance of Sn-ZnS was higher as compared to pure ZnS. Results of antibacterial studies revealed that the synthesized NPs were more active against E. coli in all concentration as compared to others.

Physical properties of Mg doped ZnS thin films via spray pyrolysis

Chemical spray pyrolysis (CSP) was utilized to create pure Zinc Sulfide (ZnS) and magnesium (Mg) doped thin films on a clean glass substrate at a temperature equal to 400°C. X-ray diffraction test revealed a cubic wurtzite crystal structure with average crystallite sizes of 10.99 and 12.27 nm for ZnS and ZnS: Mg, respectively. XRD analysis of the doped films revealed a polycrystalline structure with a predominant peak along the (220) plane and additional peaks along the (111), (200), and (222) planes. The grain size raised from 10.99 to 12.27 nm as a result of the XRD patterns. The increase in Mg content from 0% to 3%, affect the bandgap that fell from 3.52 to 3.42 eV. As the Mg content increased, the transmittance and refractive index of the films was lowered.

Preparation and analysis of Ag2Se1-xTex thin film structure on the physical properties at various temperatures by thermal evaporation

Chemical spray pyrolysis (CSP) was utilized to create pure Zinc Sulfide (ZnS) and magnesium (Mg) doped thin films on a clean glass substrate at a temperature equal to 400°C. X-ray diffraction test revealed a cubic wurtzite crystal structure with average crystallite sizes of 10.99 and 12.27 nm for ZnS and ZnS: Mg, respectively. XRD analysis of the doped films revealed a polycrystalline structure with a predominant peak along the (220) plane and additional peaks along the (111), (200), and (222) planes. The grain size raised from 10.99 to 12.27 nm as a result of the XRD patterns. The increase in Mg content from 0% to 3%, affect the bandgap that fell from 3.52 to 3.42 eV. As the Mg content increased, the transmittance and refractive index of the films was lowered.

Green synthesis of carbon-supported ultrafine ZnS nanoparticles for superior lithium-ion batteries.

Zinc sulfide (ZnS) is a promising anode material for lithium-ion batteries (LIBs) because of its high theoretical capacity, abundance, cost-effectiveness, and environmental friendliness. Herein, a hydrangea-like ZnS-carbon composite (ZnS-NC) is synthesized through the hydrothermal method and subsequent pyrolysis of a supramolecular precursor guanosine. The resulting composite comprises ultrafine ZnS nanoparticles firmly stabilized on a nitrogen-doped carbon matrix, featuring mesoporous channels and high surface areas. When utilized as an anode material for LIBs, the initial discharge specific capacity of the ZnS-NC electrode reaches an impressive value of 944 mA h g-1 at 1.0 A g-1, and even after 450 cycles, it maintains a reversible capacity of 597 mA h g-1. Compared with pure ZnS, the ZnS-NC composite exhibits significantly improved rate performance and cycling stability. This enhancement in Li-storage performance can be attributed to a synergistic effect within the ZnS-NC composite, which arises from the large exposed active site area, efficient ion/electron transfer, and strong interaction between the ZnS nanoparticles and the carbon framework. Overall, this work presents an eco-friendly approach for developing metal sulfide-carbon composites with exceptional potential for energy storage applications.

Optical characteristics of Al-doped ZnS thin film using pulsed laser deposition technique: the effect of aluminum concentration

"An efficient pulsed laser deposition (PLD) method was used to create un-doped and aluminum (Al) doped zinc sulfide (ZnS) nanomaterial. The effect of Al concentration on optical properties was investigated using two different techniques; namely, Ultra-violate visible light (UV-Vis) and Photoluminescence (PL) spectroscopies. Specifically, the optical analysis revealed a decrease in the optical bandgap values from 3.5 to 3.28 eV upon the addition of 8% of Al as dopant. While, the PL spectra of all samples showed a broad emission band in the 300-500 nm range. ZnS emission bands with Gaussian fitting are located at 396 and 459 nm. Despite from the pure ZnS peaks, three additional peaks at 345, 369, and 386 nm are observed for Al doped ZnS nanomaterial. Additionally, increasing the Al content up to 6% resulted in enhanced photoluminescence, but above this level, photoluminescence quenching was observed."

Enhanced photodegradation of methylene blue from aqueous solution using Al-doped ZnS nanoparticles.

The post-transition semiconducting material of pure zinc sulfide (ZnS) and various concentrations of aluminum (Al) (2.5 wt%, 5.0% wt, 7.5 wt%, and 10% calcined at 200 °C) doped ZnS nanoparticles (NPs) were synthesized by sol-gel procedure. The crystal-like nature and phase structure of the product were examined by powder XRD analysis. This analysis shows that the pure ZnS nanoparticle does not form any secondary phase. The functional group of synthesized materials was analyzed by FTIR examination. The energy gap of the materials is calculated using electro-optic analysis and the Kubelka-Munk equation varies from 3.04 nm to 3.63 nm. The photoluminescence studies show the wide emissions (blue to green) for pure ZnS and Al-doped ZnS nanomaterials. The SEM images show the spherical structure and the agglomerated nanostructures. The presence of Zn, S, and Al are confirmed by EDAX spectra. From HR-TEM studies, pure ZnS and Al-doped ZnS nanoparticles exhibit uniform particle sizes. The rate of degradation was observed using MB dye. MB dye has maximum wavelength (λmax) of 664 nm. The dye degradation efficiency was improved as the dye ratio increased. Photocatalytic activities studies show the intensity of photocatalytic activities decreased for the maximum time interval. Doping of Al in ZnS boosts the photocatalytic activity. Hence, Al-doped ZnS appears to be better decomposing MB dye when exposed to visible light.

Tin Decorated Zinc Sulphide Nanoparticles for Photocatalytic Degradation of Bromophenol Blue Dye and Their Therapeutic Applications: A Kinetic and Thermodynamic Approach

Zinc sulphide (ZnS) and Tin doped Zinc sulphide (Sn-ZnS) nanoparticles (NPs) were synthesized by co precipitation method. The synthesized NPs were characterized using UV–vis spectroscopy, X-ray diffraction (XRD), Energy dispersive X-ray analysis (EDX), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Thermo gravimetric analysis (TGA) and Photoluminescence (PL) spectroscopy. With the addition of 3% tin the band gap of ZnS reduced from 3.50 eV to 3.10 eV which confirmed successful doping. XRD study showed cubic crystal structure of the synthesized material while SEM study confirmed that Sn-ZnO NPs have spherical surface morphology. TGA study revealed that the synthesized NPs are much stable to temperature and only 22.8% and 21.5% weight loss occurs in ZnS and Sn-ZnS nanocatalys respectivelyt. The photoluminescence (PL) intensity showed that with Sn doping peak in Sn-ZnS shifted to longer wavelength required lesser energy for excitation. The degradation of Bromophenol blue over both the catalysts followed first order kinetics. The activation energy calculated for the photodegradation reaction was 53.2kj mol−1 and 67.55kj mol−1 using pure ZnS and Sn-ZnS NPs respectively. About 86% and 96% dye degradation was observed in 300 min time duration. High percent degradation was found at low dye concentration (10ppm) and at optimal dosage (0.03 g) of the catalyst. The rate of dye degradation was found to increases with increase in temperature (upto 70 °C) and pH(9.5) of the medium. The recyclability study showed that both pure ZnS and Sn-ZnS NPs could be reused for the degradation of the given dye. Sn-ZnS NPs showed good antibacterial and antioxidant activities as compared to bare ZnS. Both the nanoparticles are found to be non biocompatible.

Structural, optical and antimicrobial activity of Ferric doped zinc sulphide (ZnS) nanoparticles

The current study focuses on the preparation of pure and Ferric doped zinc sulphide (ZnS) using a wet chemical process. The formation of cubic ZnS was verified by X-ray diffraction (XRD) analysis of all prepared samples. The average crystallite particle size of pure and Fe (3%) and Fe (5%) doped ZnS is 33.95 nm, 23.50 nm, and 15.18 nm, respectively. With increasing Fe ion doping concentration, the optical band gap of doped ZnS nanoparticles decreases. Fourier transform infrared spectra confirmed the existence of chemical bonding. The antimicrobial tests were tested against standard bacterial strains.

Graphene‐doped ZnS nanoparticles synthesized via hydrothermal route for enhanced electrocatalytic performance

AbstractEnergy and ecological issues increase high stress on the growth of a sustainable energy system. Better electrocatalysts is an imperative way to achieve this goal. This manuscript highlights the electronic energy state and surface area engineering of zinc sulfide (ZnS) in the nanoscale regime. These properties make ZnS, an appropriate electrocatalyst for various energy applications. It was attained by controlling the concentration of graphene into ZnS nanoparticles. Graphene‐doped ZnS nanoparticles were synthesized by simple hydrothermal route. Graphene hugely affects the structural, surface, optical, and electrochemical properties of ZnS nanoparticles. Here, 10% doping of graphene into ZnS nanoparticles double its surface area, and consequently, all other properties get varied. This sample shows the highest specific surface area of 143.05 m2/g and the highest pore diameter value of 6.02 nm. Electrocatalytic performance for synthesized samples has been verified using electrochemical impedance spectra (EIS) and cyclic voltammetry (CV) analysis. Using CV data analysis, peak current response with scan rate suggests that synthesized samples with higher graphene concentration have poor capacitive behavior. ZnS with 10% concentration of graphene possesses the highest capacitive behavior due to the fast transfer of charge/ions. Rate of flow of charge/ions into or on the electrodes is measured by a quantity called diffusion coefficient, have been calculated. Hence, the optimization of the doping concentration of graphene on ZnS is essential to obtain enhanced properties for energy applications. Also, the large concentration of graphene shield the absorption of electrolyte on ZnS surface, leading to weak electrocatalytic performance. EIS analysis reveals that smaller solution resistance and charge transfer resistance values are a sign of better electrical conductivity and electrocatalytic activity of the electrode materials. Various other characteristics studies like field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR), and X‐ray photoelectron spectroscopy (XPS) have been done to confirm graphene‐doped ZnS nanoparticles’ formation and compare the properties variation from pure ZnS to graphene‐doped ZnS nanoparticles.

Investigating photoluminescence properties of Ca-doped ZnS nanoparticles prepared via hydrothermal method

The structural, morphological and optical properties of pure and Ca-doped zinc sulfide (ZnS:Ca) nanoparticles (NPs) prepared by hydrothermal method at different percentages of Ca are reported herein. The resulting NPs were characterized by X-ray diffraction analysis (XRD), Raman scattering, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. The XRD patterns confirmed the crystalline nature of all pure and doped NPs showing a single phase cubic blende structure, whereas the SEM micrographs showed sphere-shaped NPs. The sizes of the as-prepared NPs estimated by TEM were found to be in the range 44–147 nm. The PL emission spectra of ZnS:Ca nanocrystals excited at 400 nm consist of a broad band (420 nm–640 nm) characterized by two main contributions peaking at 484 and 533 nm. The overall maximum emission intensity is found for ZnS:3% Ca with internal quantum yield of 8.4%.

Static wetting angles of water and sulphur at the zinc sulphide surface modified with anionic surfactants and their combinations

This paper looks at the effect produced by surface modification of the super pure zinc sulphide monocrystals with certain surfactants and their combinations (sodium lignosulphonate (SLS), sodium dodecyl sulphate (SDS), sodium dodecylbenzenesulphonate (SDBS) and the following combinations: SLS + SDS, SLS + SDBS on the surface angle of wetting with water and elemental sulphur melt. It was found that as the concentration of individual surfactants in the solution rose, so did the wetting ability of the mineral surface. Thus, at the surfactant concentration of 0.8 g/dm3 the water wetting angle reaches 48.4o for SLS, 22.5o for SDS and 10.3o for SDBS; the elemental sulphur wetting angle is 71.3o for SLS, 76.9o for SDS and 67.9o for SDBS. The work of adhesion in the system ZnS – Surfactant – Н2О increases by 9–11%, and in the system ZnS – Surfactant – S0 — by 5–8%. When using the combinations SLS + SDS (СSLS = 0.2–0.8 g/dm3) and SLS + SDBS (СSLS = 0.2 g/dm3), inverse surface wetting of zinc sulphide with elemental sulphur melt is observed. The maximum wetting angles reached are 93o and 85o, correspondingly. The work of adhesion and the spreading coefficient expectedly decrease. The paper analyzes the effect of individual surfactants and their combinations on the pressure leaching of zinc sulphide concentrate. The use of individual surfactants intensifies the transition of valuable components into the solution. The biggest increase in recovery was seen when using SLS, and namely 27–32% for zinc and 11–16% for copper. The recovery of zinc increased by 31–41% in the presence of SLS + SDS and by 27–34% in the presence of SLS + SDBS. This research was funded by the Russian Science Foundation, Grant No. 18-19-00186.