Doped ZnS Research Articles

Investigation of antibacterial and anticancer activities of copper, aluminum and nickel doped zinc sulfide nanoparticles

First time compared the different metals doped ZnS nanoparticles for antibacterial and liver cancer cell line. In this study, copper, aluminum and nickel doped ZnS NPs were synthesized via co-precipitation method. The XRD analysis was confirmed the presence of cubic crystal structure and crystallite size decreased from 6 to 3 nm with doping elements. While as SEM micro-grains were revealed slightly irregular and agglomerated morphology with the presence of dopant elements. The presence of different dopant elements such as Cu, Al and Ni in ZnS NPs was identified via EDX analysis. The FTIR results demonstrate various vibrational stretching and bending modes attached to the surface of ZnS nanomaterials. After that the well diffusion method was used to conduct in-vitro bioassays for evaluation of antibacterial and anticancer activities against E.coli and B.cereus, as well as HepG2 liver cancer cell line. Our findings unveil exceptional results with maximum inhibition zone of approximately 9 to 23 mm observed against E.coli and 12 to 27 mm against B.cereus, respectively. In addition, the significant reduction in cell viability was achieved against the HepG2 liver cancer cell line. These favorable results highlight the potential of Ni doped ZnS NPs for various biomedical applications. In future, the doped ZnS nanomaterials will be suitable for hyperthermia therapy and wound healing process.

Enhancement of the photocatalytic activity of fabricated ZnS nanoparticles in the photodegradation of methylene blue

This paper first aims to synthesize and characterize ZnS nanoparticles (NPs) by the hydrothermal method. The synthesized NPs are investigated by x-ray diffraction (XRD), field emission electron microscopy (FE-SEM), energy-dispersive x-ray spectroscopy (EDX), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), ultraviolet-visible (UV–vis) spectroscopy, N2 adsorption-desorption, diffuse reflectance spectroscopy (DRS). Thiosemicarbazide/Zinc acetate dehydrate/ Ethylenediamine/Deionized water are utilized as precursors with three molar ratios and labeled as S1 = 2:1:1:1, S2 = 2:1:1:3 and S3 = 1:2:2:2, respectively. The synthesized pure ZnS NPs under UV irradiation present a higher photodegradation rate in comparison with the existing pure and doped ZnS-based ZnS. The direct optical bandgap of S1, S2 and S3 are estimated by the DRS method and approved by the Tauc method as 3.29 eV, 3.38 eV and 3.37 eV, respectively. The photocatalytic activities of the synthesized pure NPs (S1, S2 and S3) are calculated to be 0.044, 0.036 and 0.050 min−1, respectively. The results indicate the significant effect of precursors on the crystallite phase, optical bandgap and photocatalytic activity of the ZnS NPs so that in comparison with other studies, they could be an effective candidate in the field of photodegradation of the organic dyes.

Structural, morphological, optical, photoluminescent and electrochemical performance of ZnS quantum dots: Influence of Mn2+ and La3+ ions

The Mn, La dual doped ZnS QDs synthesized using co-precipitation method and the XRD analysis confirmed the cubic phase and HR-TEM estimates the average crystallite size ∼ 2 nm. FT-IR spectroscopy and EDAX ensure the purity of the prepared samples. The surface morphological examination discovered the surface structure and particle aggregation of the sample. From the UV-visible optical spectroscopy, It is observed that La 2% doped Mn:ZnS tuned large band gap (3.98 eV).The size dependence of the Zn0.98-xMn0.02LaxS QDs appears to be confirmed by the apparent shift of the absorption and emission peaks of the QDs. The optical absorbance was increased as the increase of La concentration. Defect-induced red emission was obtained through PL study. The Cyclic Voltagram (CV) findings demonstrate that the electrical properties of ZnS electrolytes can be further enhanced by co-doping with an ideal ratio of La3+ and Mn2+ ions.

Electrochemical sensing of carcinogenic p-dimethylamino antipyrine using sensor comprised of eco-friendly MoS2 nanosheets encapsulated by PVA capped Mn doped ZnS nanoparticle

Electrochemical sensing of carcinogenic p-dimethylamino antipyrine using sensor comprised of eco-friendly MoS2 nanosheets encapsulated by PVA capped Mn doped ZnS nanoparticle

PVA Capped Mn-Doped ZnS Encapsulated Nontoxic MoS2 Nano-Sheet Probe for the Sensitive Estimation of Cardiovascular β-Blocking Agent Acebutolol in Biomedical and Environmental Samples

In the present study, a novel sensor PVA capped Mn doped ZnS incorporated MoS2 nanosheet composite modified gold electrode (PVA-Mn:ZnS/MoS2@GE) has been developed for the determination of acebutolol (ACB). Cyclic voltammetry (CV) and square wave voltammetry (SWV) were used to measure the electrochemical performance of ACB. When nanocomposite PVA-Mn:ZnS/MoS2 was used as a modifier in electrode-based sensors, results in well-resolved peaks and improved electrochemical current sensitivity compared to bare gold electrode. Using the SWV technique in pH 7.0 phosphate buffer, the examination of samples of biological, environmental and tablet spiked with ACB was monitored, the limit of detection and quantification is found to be 0.38 × 10−9 M and 1.28 × 10−9 M respectively. CV, energy dispersive X-ray, scanning electron microscopy, and impedance spectroscopy were performed to characterize the electrode material. A suitable mechanism was proposed for the number of protons and electrons involved in the redox reaction of ACB.

Magnetic, Phonon and Optical Properties of Transition Metal and Rare Earth Ion Doped ZnS Nanoparticles.

The surface, size and ion doping effects on the magnetic, phonon and optical properties of ZnS nanoparticles are studied based on the s-d model including spin-phonon and Coulomb interaction, and using a Green's function theory. The changes of the properties are explained on a microscopic level, due to the different radii between the doping and host ions, which cause different strains-compressive or tensile, and change the exchange interaction constants in our model. The magnetization increases with increasing small transition metal (TM) and rare earth (RE) doping concentration. For larger TM dopants the magnetization decreases. The phonon energies increase with increasing TM, whereas they decrease by RE ions. The phonon damping increases for all doping ions. The changes of the band gap energy with different ion doping concentration is also studied. Band gap changes in doped semiconductors could be due as a result of exchange, s-d, Coulomb and electron-phonon interactions. We have tried to clarify the discrepancies which are reported in the literature in the magnetization and the band gap energy.

Interrelation of micro-strain, energy band gap and PL intensity in Ce doped ZnS quantum structures

Three-dimensional (3-D) quantum structures (QSs) of ZnS and Cerium (Ce) doped ZnS were synthesized via chemically affordable sol-gel process. Influence of Ce doping and thus induced micro-strain on the structural, morphological, and optical characteristics was explored. XRD confirmed the formation of single-phase zinc blende ZnS. Estimated average crystal size corresponding to highest intensity XRD peak (111) varied within 1.65–4.65 nm which are comparable with Bohr radius of ZnS. Due to the size mismatch between Ce and Zn, micro-strain and vacancies were found to be developed in host matrix of ZnS. Thermodynamic calculations validated an expansion and contraction in lattice parameter due to Ce doping. FTIR spectra confirmed the presence of different functional groups related to Zn and S. Photoluminescence (PL) emissions observed at 420, 461, 509 and 560 nm are related to the defect states such as interstitial sulfur, zinc interstitial, sulfur vacancies and zinc vacancies respectively. Rise of another emission peak in doped ZnS at 600 nm was due to 5d → 4f energy level transitions in Ce3+ ions. Evolved micro-strain profile, PL intensity and energy band gap variation were analogous to each other with respect to doping concentration. Microscopic images confirmed the structural transformation to cuboidal shaped ZnS QSs with increase in doping concentration. EDX and XPS supported the elemental analysis along with oxidation states of the available elements such as Zn, S and Ce.

Fluorescent sensor based on thiourea capped Mn doped ZnS quantum dots for the sensing of Cu2+ ions in water

In the present study the utilization of a simple, rapid, and highly effective “turn-off” fluorescent sensor based on thiourea capped manganese doped zinc sulphide quantum dots for the detection of Cu2+ ions in water is described for the first time. The quantum dots are prepared by a simple and facile chemical precipitation method. The developed quantum dots are characterized by UV–vis., FT-IR, photoluminescence, XRD, and TEM techniques. The doping by manganese is confirmed by a peak at 598 nm in the PL spectrum. The sensor exhibit high sensitivity and selectivity towards copper ion at pH 9 with a limit of detection of 20.75 nM. The obtained results are also reasonable in real sample analysis.

One-Pot Synthesis of Biocompatible Glycine Protected Chromium Doped ZnS Nanoparticles and their Optical Properties

Here in, we report the synthesis and characterization of Chromium doped Zinc Sulfide nanoparticles (ZnS NPs). Initially, ZnS NPs are synthesized by bio-compatible glycine cap using simple one-pot co-precipitate method, and further it is doped by Chromium. The structure and morphology of these ZnS NPs was confirmed by X-Ray Diffractometry (XRD) and Scanning Electron Microscope with Elementary Dispersive Spectrum (SEM with EDS) techniques. The optical characterization techniques reveal that the Chromium doping affected the absorption and photoluminescence properties of the NPs. Photoluminescence of these NPs shifts from 384 nm to 428 nm upon Chromium doping. By using Tauc plot we obtained the energy band gap of 4.7 eV and it reduces to 3.9 eV for Chromium dope. The resultant ZnS NPs have size of 2.17nm and 1.86nm (with Chromium doping), also it gives Cubic Zinc blend phase as proved by XRD. The instrumentation techniques SEM with EDS, XRD, FTIR confirms that high purity Chromium doped ZnS NPs can be obtained by the proposed simple, low cost and highly effective method.

Enhanced orange emission of Zn0.98–XMn0.02CoxS (x = 0[formula omitted]0.02) quantum dots

Mn 2+, Co2+ ions double doped ZnS was obtained via co-precipitation technique under room temperature. The doping concentration of Mn2+ was fixed as 2 at. wt% and Co2+ was varied from 0 to 3%. The synthesized products were analyzed using XRD, SEM, EDX, UV–vis optical study, FT-IR spectra and PL spectra. The synthesized nanostructures size was determined from XRD results and they were in the range of 2.9 to 3.7 nm and the size was increased for Co2+ 1 at. wt% doping. All the samples had a cubic structure without a trace of any secondary phases. The optical band gap values are red-shifted due to the increase of Co2+ concentration. A higher UV–vis optical transmittance was offered by 1 at. wt% Co2+ doped Mn:ZnS nanostructures. PL emissions noticed at 472 and 592 nm. These blue and orange emissions were addressed by the creation of trap states due to the incorporation of Co2+ ions and the emission intensity was increased at higher composition of dopant. The creation of more charge carriers and the generation of defects are responsible for the improved catalytic behavior in Co = 2% doped Zn0.98Mn0.02S which established superior efficiency after sex re-cycling progression.

Optimization of chemically sprayed ZnS films by Mn doping

In this study, undoped and Mn doped ZnS films were grown on microscope glass substrates at substrate temperature of 400 ± 5 °C by using a low cost Ultrasonic Spray Pyrolysis technique, and the effect of Mn doping on some physical properties of ZnS films was investigated. Structural, optical, electrical and morphological properties of all films were analyzed using X-ray diffractometer (XRD), UV–Vis spectrophotometer, two-probe technique and atomic force microscope (AFM), respectively. X-ray diffraction studies showed that all films were formed in ZnS hexagonal structure and the crystallization levels of the films were relatively improved due to the increase in the Mn doping ratio, especially for 4% doped films. It was determined that the average transmittance value of undoped ZnS film in the visible region is 38% and this value increases to 60% for the sample doped by Mn at the highest rate (12%). The band gap values of the films were calculated using the Tauc equation and determined to be between 3.82 and 3.94 eV. Electrical resistivity values of the films decreased significantly due to the Mn doping. Mn doping also caused ZnS films to have uniform surface morphologies consisting of noticeable particle formations. Figure of merit calculations showed that Mn doping has a favorable effect on ZnS films and ZnS:Mn (12%) films may be promising materials for applications such as photovoltaic solar cells and optoelectronic devices.

Solochrome Dark Blue Azo Dye Removal by Sonophotocatalysis Using Mn2+ Doped ZnS Quantum Dots

This work investigates the degradation of the azo dye solochrome dark blue (SDB) by measurement of the photocatalytic, sonocatalytic and sonophotocatalytic activities, under low ultrasonic frequency (40 kHz) and UV-C (254 nm) light, using Mn-doped ZnS semiconductor quantum dots (Mn2+:ZnS Qds) as catalysts, prepared by a simple chemical precipitation procedure. In order to study the different morphological and optical crystal properties, various characterization techniques were used, such as high resolution transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, N2 adsorption-desorption at −196 °C and ultraviolet-visible spectroscopy. The average particle size of the semiconductor Qds was in the range of 3–4 nm. The optimal parameters affecting dye degradation, such as the catalyst loading, solution pH, time of irradiation, initial concentration of dye, dopant concentration, ultrasonic power and frequency effect were evaluated. The synthesized catalytic material exhibited a high activity for sonophotocatalytic degradation of SDB (89%), larger than that observed for sonocatalysis (69.7%) or photocatalysis (55.2%) alone, which was due to the improved electron-holes separation, formation of more reactive radicals and enhancement of the active surface area. Qds showed good stability and reusability after five repeated cycles. Finally, the degradation products were identified by liquid chromatography-mass spectrometry (LC-MS).

CeO2 supported Zn1-xMnxS (x: 0.025, 0.05, 0.075 and 0.10) catalyst for photoremoval of rhodamine B dye

Present work provides a detailed study of enhanced photocatalytic performance of CeO2 coupled Mn-doped ZnS nanoparticles. In a systematic study, undoped and Mn− doped (2.5, 5, 7.5 and 10 mol%) ZnS nanoparticles were synthesized using co-precipitation method. Then, using synthesized samples, heterostructure samples (ZnS/CeO2) were prepared by hydrothermal route. Successful incorporation of Mn ions in ZnS lattice was determined by X-ray diffraction, transmission electron microscopy and Fourier-transform infrared spectroscopy. Optical spectroscopies revealed the associated optical modifications because of Mn-doping and confirmed CeO2 attachment. The specific surface area calculated from N2 sorption isotherms suggested the mesoporous structure of the samples. Rhodamine B (RhB) dye was used to understand the structural modifications of both components for the photocatalytic performance under different radiations. It was observed that hydroxyl radicals (OH∙) were responsible for photo-oxidation of RhB molecule with excellent photostability of synthesized heterostructure sample under UV–visible illumination. To prove photocatalytic activity of catalysts under visible light, additional experiments with the use of vancomycin antibiotic, which do not absorb visible light, were performed. Though Mn doping improves the recombination rate of charge carriers of host ZnS, the attachment of CeO2, not even reduces the optical bandgap (red shift) but contributes to better separation of the photo-excited charge carriers in heterostructure catalysts.

Highly sensitive detection for alkaline phosphatase using doped ZnS quantum dots with room temperature phosphorescence and its logic gate function

This paper presents a highly sensitive sensing system for alkaline phosphatase by room temperature phosphorescence of Mn doped ZnS quantum dots and pyrophosphate. The sensing system has intense room temperature phosphorescence emission in the absence of alkaline phosphatase. The phosphorescence is quenched gradually with the addition of alkaline phosphatase. The emission “on” without alkaline phosphatase may be attributed to the increased probability of charge transfer from one of surface traps to the dopant bands of another resulted from the shortened dot-to-dot distance by the strong chelation of pyrophosphate and Zn2+ ion and the hydrogen bonding between pyrophosphate and β-cyclodextrin. The addition of alkaline phosphatase causes pyrophosphate hydrolyzed to orthophosphate and the dot-to-dot distance of quantum dots back to the normal, and then the phosphorescence “off”. The factors affecting the sensing system performance were also optimized. Under the optimal experimental conditions, the linear range for alkaline phosphatase is determined as 0.2−10 U/L with a LOD at 0.045 U/L. The recovery of human serum was determined from 93.75%–103.03%, indicating a potential application in biomedical diagnosis. Furthermore, an RTP-based “INHIBIT” logic gate using the doped ZnS quantum dots was also presented.

Synthesis and luminescence properties of chemically synthesized ZnS nanomaterials

Pure and Cu-doped ZnS nanomaterials were successfully synthesized at room temperature by the chemical co-precipitation method. X-ray diffraction (XRD) pattern shows that the synthesized nanomaterials have a cubic blended structure, and the size of crystallites is around 2–3 nm. These results were confirmed by transmission electron microscopy (TEM), which matched well with the XRD results. Scanning electron microscopy and TEM micrographs of ZnS nanomaterials were in spherical shaped nature. The chemical composition is found in pure and doped ZnS nanomaterials using EDAX spectra. UV-Vis spectra show the absorption peak between 310 and 320 nm. Photoluminescence studies reveal sharp emission peaks at 439, 450 and 466 nm with decreasing intensity for pure and doped nanomaterials.

Synthesis, characterization, and photocatalytic activity of ZnS and Mn-doped ZnS nanostructures

Semiconductor quantum dots such as zinc sulfide have interesting potential applications, due to their size-dependent optical properties. These nanostructures can be used for applications in agriculture, environmental chemistry, and fluorescence microscopy. The great rise in nanotechnology has sparked the scientific community’s interest in nanomaterials for the use of photodegradation in aquatic bodies. Quantum Dots (QDs) such as ZnS nanoparticles (NPs) can absorb electromagnetic radiation and generate subsequently reactive oxygen species (ROS) directly in aqueous phase. The presence of ROS in aquatic environments can be used to destroy organic contaminants by photocatalysis. Previous studies had evidenced that the presence of impurities (i.e. copper, manganese, nickel) in the crystalline structures of QDs can enhance their optical properties and consequently their catalytic capacity. Because of this, the present investigation was focused on generating water stable ZnS nanoparticles with catalytic properties. In this work, we have synthesized pure and doped ZnS nanoparticles using a reflux method. The morphology of these QDs was characterized by transmission electron microscopy (TEM). We also studied the photocatalytic properties of these nanostructures. A red shift was observed in the photoluminescence peak of pure ZnS nanoparticles when they were doped with heavy metals. Pure ZnS NPs and Mn-doped ZnS NPs showed luminescent peaks at 444 nm and 596 nm, respectively. Photodegradation studies were evaluated in the presence of organic dyes like Tropaeolin O (TO) and different concentrations of quantum dots (250 ppm and 500 ppm). The photodegradation of TO was dependent on the QDs concentration and exposure time. The destruction of organic dyes in the presence of photo-excited ZnS nanoparticles is envisioned as a fast and clean technology. The destruction of organic dyes in the presence of photo-excited ZnS nanoparticles is envisioned as a fast and clean technology.

Optical and antibacterial evaluation of biofunctionalized Cu:ZnS nanoparticles

This article focuses on the surface stabilization of ZnS NPs doped with Cu2+ ions by casein with relatively different concentrations through microwave method. The surface attributes of the fabricated NPs were characterized by FTIR, XRD, TEM, HRTEM, and EDS measurement which showed the incorporation of Cu ions in doped ZnS NPs. Optical properties were studied using UV–vis and PL spectroscopy. XRD pattern showed zinc blend structure for both uncapped and capped. Absorption spectrum was an evidence for the strong confinement effect in the form of blue shift. Spherical shape with 8 nm (uncapped) and 3 nm (capped) were specified from TEM images. PL spectrum covered UV and visible regions with shift in the emission peak towards a shorter wavelength side. Biological activity of capped NPs was highly effective against various bacterial strains with enhanced luminescence property, which makes them to materialize as an innovative division of antibacterial agent.

Femtosecond Double-Pulse Laser Ablation and Deposition of Co-Doped ZnS Thin Films.

Nanostructured thin films of Co-doped zinc sulfide were synthesized through femtosecond pulsed laser deposition. The scheme involved ablation of physically mixed Co and ZnS with pairs of ultrashort pulses separated in time in the 0–300 ps range. In situ monitorization of the deposition process was carried out through a simultaneous reflectivity measurement. The crystallinity of generated nanoparticles and the inclusion of Co in the ZnS lattice is demonstrated by transmission electron microscopy and energy dispersive X-ray microanalysis (TEM-EDX) characterization. Surface morphology, Raman response, and photoluminescence of the films have also been assessed. The role of interpulse temporal separation is most visible in the thickness of the films obtained at the same total fluence, with much thicker films deposited with short delays than with individual uncoupled pulses. The proportion of Co in the synthesized doped ZnS nanoparticles is found to be substantially lower than the original proportion, and practically independent on interpulse delay.

Development of ZnS thin film with Co, Cu and Ag doping using SILAR method

Pure and doped ZnS thin films were synthesised using Successive Ionic Layer Adsorption and Reaction (SILAR) over glass substrate with 15 deposition cycles at ambient temperature. In this study, pure ZnS nanoparticles were doped with the Cu, Co and Ag elements. The structural and optical properties of pure and doped ZnS thin films were explored. The structural and morphological properties of pure and doped ZnS thin films were characterized by powder X-ray diffraction and Scanning Electron Microscope (SEM). The SEM images confirmed that average diameter of nano-particles of ZnS was between 53 and 90 nm. Optical properties determined from UV–VIS spectrophotometry were used to analyse the measured absorbance. The Zinc sulphide thin film shows high absorption in the visible region. Further, ZnS doped with Co, Cu and Ag with doping concentration of 3% was investigated for the feasibility and quality of the solar cells. The optical absorption peak was approximately located at 350 nm. The increase of bandwidth with decrease of the absorption values were observed with doped ZnS thin films and the Ag doped ZnS thin film has broad absorption spectra over the visible light region.

Two‐Fragment‐Dummy‐Template Molecularly Imprinted Polymers Mn Doped ZnS Quantum Dots Based Room‐Temperature Phosphorescene Probing for Hepatotoxic Homologues of Microcystin

AbstractFragment‐dummy‐template molecularly imprinted polymers‐Mn doped ZnS QDs (FMIP−Mn doped ZnS QDs) were synthesized by surface imprinting technique and specifically recognize microcystin (MC), especially MC‐LR, MC‐RR and MC‐YR. Pentylbenzene and L‐arginine were used as fragment dummy template of MC to form specific recognition site cavity. The introduction of dummy template reduced the toxicity and cost of MC as template in the synthesis process. When MC was added to the FMIP, the room temperature phosphorescence (RTP) intensity is quenched regularly, thereby achieving the effect of detecting MC. The two‐fragment‐dummy‐template molecularly imprinted polymers‐Mn doped ZnS QDs (FMIP‐1) have distinct linearly RTP quenching toward MC in the concentration range of 0.0025‐0.0175 nM. The linear relationship between ΔP/P0 and CMC‐LR, CMC‐YR and CMC‐RR were observed with the regression equation ΔP/P0=0.0150+24.70CMC‐LR, ΔP/P0=0.0995+21.38CMC‐YR, and ΔP/P0=0.101+16.96CMC‐RR (where concentration was in nM), with the detection limit of 0.25 pM, 1 pM and 0.6 pM, respectively. This method was applied to detect MC in water and freshwater products. The method have the potential for effective detection of other harmful substances in the complicated matrix.