Effect of ammonium sulfate on the formation of zinc sulfide species on hemimorphite surface and its role in sulfidation flotation

Effectively strengthening the surface sulfidation is essential for recovering hemimorphite by froth flotation.In this work,inductively coupled plasma optical emission spectrometer(ICP-OES)measurements,Visual MINTEQ calculation,X-ray photoelectron spectroscopy(XPS)analysis,time of flight secondary ion mass spectrometry(ToF-SIMS)analysis,and micro-flotation experiments were explored to systematically investigate the effect of ammonium sulfate((NH_(4))_(2)SO_(4))on the formation of zinc sulfide species on hemimorphite surface and its role in sulfidation flotation.The results showed that(NH_(4))_(2)SO_(4)exhibited a positive influence on hemimorphite sulfidation flotation.It was ascribed to the number of zinc components in the form of Zn^(2+)and[Zn(NH_(3))_(i)]^(2+)(i=1–4)increased in the flotation system after hemimorphite treatment with(NH_(4))_(2)SO_(4),which was beneficial to its interaction with sulfur species in solution,resulting in a dense and stable zinc sulfide layer generated on the hemimorphite surface.[Zn(NH_(3))_(i)]^(2+)participated in the sulfidation reaction of hemimorphite as a transition state.In addition the sulfidation reaction of hemimorphite was accelerated by(NH_(4))_(2)SO_(4).Thus,(NH_(4))_(2)SO_(4)presents a vital role in promoting the sulfidation of hemimorphite.

Pressure acid leaching of zinc sulfide concentrate

Effects of particle size of the zinc sulfide concentrate,leaching temperature,solid-to-liquid ratio and additive amount on pressure acid leaching process of the zinc sulfide concentrate were studied.The results indicate that the additive can improve the reaction kinetics and the conversion rate.And sulfur can be successfully separated from the zinc sulfide concentrate as elemental sulfur.The reasonable experiment parameters are obtained as follows:the leaching temperature 150℃,oxygen partial pressure 1 MPa,additive amount 1%,solid-to-liquid ratio 1:4,leaching time 2 h,initial sulfuric acid concentration 15%,and particle size less than 44μm.Under the optimum conditions,the leaching rate of the zinc can reach 95%and the reduction rate of the sulfur can reach 90%.

Structural and Characteristics of Manganese Doped Zinc Sulfide Nanoparticles and Its Antibacterial Effect against Gram-Positive and Gram-Negative Bacteria

The Manganese doped zinc sulfide nanoparticles of the cubic zinc blende structure with the average crystallite size of about 3.56 nm were synthesized using a coprecipitation method using Thioglycolic Acid as an external capping agent for surface modification. The ZnS:Mn2+ nanoparticles of diameter 3.56 nm were manufactured through using inexpensive precursors in an efficient and eco-friendly way. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy are used to examine the structure, morphology and chemical composition of the nanoparticles. The antimicrobial activity of (ZnS:Mn2+) nanocrystals was investigated by measuring the diameter of inhibition zone using well diffusion mechanism versus two various bacterial strains. The technique of microorganism inactivation was considered as sorts-dependent. Bacillus subtilis showed the largest antibacterial sensitivity (35 mm) to ZnS: Mn2+ nanoparticles at a concentration (50 mM) whereas Escherichia coli offered maximum zone of inhibition (20 mm) at the same concentration. In this study, the results indicated that ZnS:Mn2+ nanoparticles were found to have significant antibacterial activity against Gram-negative (E. coli) and Gram-positive (Bacillus subtilis) bacteria.

Tailoring crystallization zinc hydroxide sulfates growth towards stable zinc deposition chemistry

The unstable zinc anode/electrolyte interface induced by corrosion,interfacial water splitting reaction,and dendrite growth seriously degrades the performances of metal Zn anode in aqueous electrolyte.Herein,the nucleation and growth of zinc hydroxide sulfate(ZHS),an interfacial by-product,has been tailored by Tween 80 in the electrolyte,which thereby assists in in-situ forming a dense solid electrolyte interphase(SEI)with small-sized ZHS and evenly distributed Tween 80.This SEI has high corrosion resistance and uniform distribution of zinc ions,which not only contributes to blocking the interfacial side reactions but also induces stable and calm zinc plating/stripping.Consequently,the modified electrolyte can confer the assembled Zn||Zn symmetric cell with a stable operation life over 1500 h at 1 mA·cm^(−2)and 1 mAh·cm^(−2)as well as the practical Zn||NH4V4O10 full battery with a high-rate capacity of 120 mAh·g^(−1)at the current density of 5 A·g^(−1).This work provides a way for regulating and reusing interfacial by-products,and a new sight on stabilization electrodes/electrolyte interfaces.

Defects in CVDZnS

Defects seriously influence the optical properties and mechanical properties of CVDZnS. The deposition technique was introduced and experiment methods such as SEM, TEM and OM were adopted to study the defects： hexagonal phase, abnormally large grains, micro-cracks, micro-pores and impurities. The microstructures of these defects were observed, and the formation mechanisms of these defects were analyzed. Hexagonal ZnS as an impurity causes anisotropy in different directions with different refraction indexes and increases the scattering of CVDZnS. Increasing the deposition temperature can inhibit the formation of the hexagonal phase. The main reason for the growth of abnormaUy large grains in CVDZnS is high deposition rate. The lower deposition temperature increases growth stress in CVDZnS, which consequently results in the bowing of CVDZnS plates, and introduces microscopic defects such as grain blending and micro-cracks in the crystal. Micro-pores and impurities are induced by high reactant concentration in the local deposition chamber, which can be avoided by improving the gas flowing so as to make the concentration more uniform.

Characterization of ZnS nanoparticles synthesized by co-precipitation method

ZnS nanoparticles are prepared by homogeneous chemical co-precipitation method using EDTA as a stabilizer and capping agent. The structural, morphological, and optical properties of as-synthesized nanoparticles are investigated using x-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible （UV-Vis） absorption, and photoluminescence spectroscopy. The x-ray diffraction pattern exhibits a zinc-blended crystal structure at room temperature. The average particle size of the nanoparticles from the scanning electron microscopy image is about 50 nm. The ultraviolet absorption spectrum shows the blue shift in the band gap due to the quantum confinement effect. The photoluminescence spectrum of ZnS nanoparticles shows a blue visible spectrum.

DRAWING PREDOMINANCE DIAGRAM OF M_1—M_2—x—y SYSTEM AND ITS APPLICATION

Discussions were made of the principle,method and computer program for drawing the pre- dominance diagrams of the bi-metal co-existed system M_1-M_2-x-y in which the multi-me- tallic compounds may be produced by interaction between compounds of both metals.The formation of zinc ferrite and its stable region have been analyzed through drawing Zn-Fe-S-O system predominance diagrams.The availability of the diagram is given the di- rection to roast the zinc sulfide ore as well.

Solvothermal Synthesis and Characterization of Zinc Indium Sulfide Microspheres

ZnIn2S4 microspheres have been solvothermally prepared at 160℃ for 12 h with ZnCl2.2H2O,InCl3,and thiourea as the starting reagents in ethanol.The morphology,structure,and phase composition of the asprepared product were characterized by means of X-ray powder diffraction（XRD）,field-emission scanning electron microscopy（FE-SEM）,X-ray photoelectron spectra（XPS）,transmission electron microscopy（TEM）,high-resolution TEM（HRTEM）,and selected area electron diffraction（SAED）.Results revealed that the prepared ZnIn2S4 microspheres were composed of sheetlike nanocrystals.The average diameter of the microspheres and the thickness of the nanosheets are about 1-6 μm and 10-50 nm,respectively.A possible growth mechanism of the ZnIn2S4 nanosheet-built microspheres was proposed and briefly discussed.

Two-dimensional porous zinc cobalt sulfide nanosheet arrays with superior electrochemical performance for supercapatteries

Unique two-dimensional(2D)porous nanosheets with overwhelmingly rich channels and large specific surface area exhibit superior electrochemical capacitance performance,as compared to the conventional zero-and one-dimensional counterparts.As ternary transition metal sulfides(TMSs)are well recognized for their high electrochemical activity and capacity,and the replacement of oxygen with sulfur may result in high stability and flexible properties of the nanomaterials,as compared to transition metal oxides,herein we report the synthesis of 2D porous nanosheet arrays of Zn_(x)Co_(1-x)S(x=0,0.25,0.5,0.75,and 1)via a facile hydrothermal process.Due to the synergistic effect of the metal components and a unique 2D porous structure,the Zn_(0.5)Co_(0.5)S electrode was found to stand out as the best among the series,with a high specific capacity of 614 C g^(-1)at 1 A g^(-1)and excellent cycle retention rate of 90%over 10,000 cycles at 10 A g^(-1).Notably,a supercapattery based on a Zn_(0.5)Co_(0.5)S positive electrode and an activated carbon(AC)negative electrode(Zn_(0.5)Co_(0.5)S//AC)was found to display a 1.6 V voltage window,a 61 mA h g^(-1)specific capacity at 1 A g^(-1),a 49 Wh kg^(-1)energy density at 957 W kg^(-1)power density,and excellent cycling performance(88%over 10,000 cycles),suggesting tremendous potential of Zn_(0.5)Co_(0.5)S in the development of high-performance supercapattery devices.

Infrastructure of Synchrotronic Biosensor Based on Semiconductor Device Fabrication for Tracking, Monitoring, Imaging, Measuring, Diagnosing and Detecting Cancer Cells

Copper Zinc Antimony Sulfide(CZAS)is derived from Copper Antimony Sulfide(CAS),a famatinite class of compound.In the current paper,the first step for using Copper,Zinc,Antimony and Sulfide as materials in manufacturing synchrotronic biosensor-namely increasing the sensitivity of biosensor through creating Copper Zinc Antimony Sulfide,CZAS(Cu1.18Zn0.40Sb1.90S7.2)semiconductor and using it instead of Copper Tin Sulfide,CTS(Cu2SnS3)for tracking,monitoring,imaging,measuring,diagnosing and detecting cancer cells,is evaluated.Further,optimization of tris(2,2'-bipyridyl)ruthenium(II)(Ru(bpy)32+)concentrations and Copper Zinc Antimony Sulfide,CZAS(Cu1.18Zn0.40Sb1.90S7.2)semiconductor as two main and effective materials in the intensity of synchrotron for tracking,monitoring,imaging,measuring,diagnosing and detecting cancer cells are considered so that the highest sensitivity obtains.In this regard,various concentrations of two materials were prepared and photon emission was investigated in the absence of cancer cells.On the other hand,ccancer diagnosis requires the analysis of images and attributes as well as collecting many clinical and mammography variables.In diagnosis of cancer,it is important to determine whether a tumor is benign or malignant.The information about cancer risk prediction along with the type of tumor are crucial for patients and effective medical decision making.An ideal diagnostic system could effectively distinguish between benign and malignant cells;however,such a system has not been created yet.In this study,a model is developed to improve the prediction probability of cancer.It is necessary to have such a prediction model as the survival probability of cancer is high when patients are diagnosed at early stages.

Antireflective films optimization of ZnS ceramics infrared windows

The transmittance characteristics of ZnS ceramics with infrared (IR) (3-5 and 8-12um) antireflective coatings are studied. The film designs are optimized with programmed software. A double-side and double-layer scheme is employed. Two different double-layers with proper pa ameters are coated onto each side of a ZnS substrate. The measurement methods for transmittance are investigated. The measured transmittance for IR (3-5 and 8-12 um) surpasses 70%.

Optoelectronic characterization of ZnS/PS systems

ZnS thin films are deposited on porous silicon （PS） substrates with different porosities by pulsed laser deposition （PLD）. The photoluminescence （PL） spectra of the samples are measured at room temperature. The results show that the PL intensity of PS after deposition of ZnS increases and is associated with a blue shift. With the increase of PS porosity, a green emission at about 550 nm is observed in the PL spectra of ZnS/PS systems, which may be ascribed to the defect-center luminescence of ZnS films. Junction current- voltage （I-V） characteristics were studied. The rectifying behavior of I-V characteristics indicates the formation of ZnS/PS heterojunctions, and the forward current is seen to increase when the PS porosity is increased.

A novel method of water remediation of organic pollutants and industrial wastes by solution- route processed CZTS nanocrystals

CZTS(Cu_(2)ZnSnS_(4)),a P-type semiconductor with a direct bandgap(1.2-1.7eV),earth-abundant,non-toxic,and has a large absorption coefficient makes it extremely useful in optoelectronics and light-harvesting applications.In this work,CZTS is prepared by an ingenious,cost-effective colloidal route using the‘hotinjection’method with the usage of different ligands.The XRD and Raman spectroscopy shows the single-phase highly crystalline CZTS nanoparticles with kesterite structure.The TEM results show that the size of CZTS nanoparticles is about 2-5 nm and monodispersity is confirmed by DLS(Dynamic Light Scattering).FTIR confirms the presence of different ligands used in CZTS preparation.The Uv-vis absorption shows the direct bandgap of 1.5-1.7eV.The contact angle study shows the hydrophobic nature of as-synthesized CZTS nanoparticles which were further ligand exchanged with L-cysteine hydrochloride to make it hydrophilic to study the photocatalytic degradation activity of organic pollutants and industrial waste in the water.The photocatalysis experiments were performed under two conditions:(i)under bare sunlight(Intensity~900 W/m^(2))(ii)focussing the sample under the sunlight via converging lens(1800 W/m^(2)).The photocatalytic efficiencies were then compared and the best photocatalytic efficiency achieved under sunlight was 98.4%for organic pollutants and 75%for industrial waste via converging lens while the corresponding efficiencies with bare sunlight were 98.1% and 73% respectively.To the best of the author’s knowledge,a rapid and highly efficient photocatalysis of CZTS NPs employing a converging lens for water-remediation without the usage of noble&transition-metals has been reported for the first time.