Synthesis Of Cadmium Sulfide Nanoparticles Research Articles

Algae mediated synthesis of cadmium sulphide nanoparticles and their application in bioremediation

The present work is a study on the biological synthesis of cadmium sulphide (CdS) nanoparticles using blue-green algae that is popularly used as a food supplement. This synthesis is unique in the sense that no external sulphur precursor is required, the CdS nanoparticles are synthesized in situ in the algal medium. The CdS nanoparticles thus synthesized are photoluminescent and can act as highly efficient photocatalysts for degradation of the dye pollutant malachite green. Thus the CdS nanoparticles synthesized in situ in the algae conform to the desired criteria of waste water treatment i.e. biosorption of the pollutant and its subsequent degradation. The novelty of this work also lies in its potential for use in bioremediation by conversion of the toxic Cd(II) ion to less toxic CdS nanoparticles within the algal framework.

Obtaining of Ultradispersed Cadmium Sulfide in a Biоpolymer Matrix

Matrix synthesis of semiconductor CdS nanoclusters is an actual task because represents a method of obtaining monodisperse and stable nanoparticles. A biopolymer films is the matrix for synthesis of cadmium sulfide nanoparticles by method of a leafwise chemosorption. The structure and optical properties of received samples are investigated. The effect of dimensional quantization for particles of ultradispersions was detected, the band gap and sizes of particles were defined. The nonuniform distribution of monodisperse cadmium sulfide nanoparticles in a matrix was determined. Mainly, they localized on sites of a biopolmer containing calcium.

Synthesis of CdS nanoparticles using different sulfide ion precursors: Formation mechanism and photocatalytic degradation of Acid Blue-29

Cadmium sulphide (CdS) nanoparticles were synthesized by different combinations of chemical precursors using H2S, Na2S and (NH4)2S as sulphide ion sources. The reactions were carried out by a single pot chemical precipitation method under ambient conditions. The X-ray diffraction (XRD) patterns obtained for the synthesized nanoparticles (NPs) were used to determine their crystal structure and the crystallite size. The average particle sizes of the synthesized nanoparticles were determined by transmission electron microscopy, UV–vis spectra and XRD techniques. Electron dispersive spectroscopy and Fourier transform infrared spectroscopy were used to investigate the purity of the synthesized CdS nanoparticles. The smaller particle size for CdS was obtained with Na2S, followed by H2S and (NH4)2S and that the quantization in the band gap was directly in correlation with decreased particle size effects. In addition, mixed phase of wurtzite–zinc blende was synthesized with H2S, while phase pure zinc blende and wurtzite phase was obtained with Na2S and (NH4)2S, respectively. The series of synthesized CdS nanoparticles were exploited for photocatalytic degradation of an organic dye derivative, Acid Blue-29, under visible light and the effect of different precursor combinations on photocatalytic efficiency was analysed. An increase in photocatalytic rate was observed by the decrease in particle size on using different sulfide ion precursors, which can be attributed to the increase in the catalyst surface area, band gap and powerful redox capability. The effect of different sulphide ion sources on the structural and photocatalytic properties was compared and optimized by the above studies.

Trichosporon jirovecii-mediated synthesis of cadmium sulfide nanoparticles.

Cadmium sulphide is one of the most promising materials for solar cells and of great interest due to its useful applications in photonics and electronics, thus the development of bio-mediated synthesis of cadmium sulphide nanoparticles (CdS NPs) is one of the essential areas in nanoparticles. The present study demonstrates for the first time the eco-friendly biosynthesis of CdS NPs using the yeast Trichosporon jirovecii. The biosynthesis of CdS NPs were confirmed by UV-Vis spectrum and characterized by X-ray diffraction assay and electron microscopy. Scanning and transmission electron microscope analyses shows the formation of spherical CdS NPs with a size range of about 6-15 nm with a mean Cd:S molar ratio of 1.0:0.98. T. jirovecii produced hydrogen sulfide on cysteine containing medium confirmed by positive cysteine-desulfhydrase activity and the colony color turned yellow on 0.1 mM cadmium containing medium. T. jirovecii tolerance to cadmium was increased by the UV treatment and three 0.6 mM cadmium tolerant mutants were generated upon the UV radiation treatment. The overall results indicated that T. jirovecii could tolerate cadmium toxicity by its conversion into CdS NPs on cysteine containing medium using cysteine-desulfhydrase as a defense response mechanism.

The photocatalytic, in vitro anthelmintic activity of biomolecule-inspired CDS nanoparticles

The photocatalytic, in vitro anthelmintic activity of biomolecule-inspired CDS nanoparticles. A simple biomolecule-inspired chemical procedure was adopted for the successful synthesis of cadmium sulphide nanoparticles (CdS-G and CdS-M) using glucose and maltose as capping agents. These nanoparticles were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy dispersive X-ray (EDAX) and Ultraviolet-Visible (UV–Vis) spectroscopy in order to evaluate their particle size, morphology, and optical properties. The photocatalytic degradation of methylene blue (MB) by CdS-G and CdS-M nanoparticles under visible light was estimated and the kinetics of photocatalytic degradation were compared by the evaluation of operational parameters viz., an amount of the photocatalyst, the pH of the solution, and concentration of the dye. The mechanism of generation of hydroxyl radicals on the surface of the CdS-G/M nanoparticles upon visible-light irradiation was confirmed by the terephthalic acid photoluminescence technique. The study of the effect of tert -butyl alcohol (TBA) and of a disodium salt of ethlyenediamine tetraacetic acid (EDTA-2Na) as scavengers, as well as photoluminescence measurements, revealed that HO • and hole (h + ) were the reactive species responsible for the degradation of MB. The anthelmintic activity of CdS-G/M nanoparticles was also evaluated.

Оцінка потенційного ризику при хімічному синтезі наночастинок сульфіду кадмію

Оцінка потенційного ризику при хімічному синтезі наночастинок сульфіду кадмію

Mechanistic aspects of biogenic synthesis of CdS nanoparticles using Bacillus licheniformis

A novel eco-friendly effort has been made for the synthesis of cadmium sulfide (CdS) nanoparticles using bacterial biomass. Although some articles have been reported on CdS nanoparticles synthesis by bacteria, here we have synthesized CdS nanoparticles using non-pathogenic bacteria Bacillus licheniformis MTCC 9555. UV-Vis spectroscopy was carried out to confirm the formation of CdS nanoparticles; the peak occurring at 368 nm gives the indication of synthesis of CdS nanoparticles. The size and morphology of the synthesized CdS nanoparticles were analyzed by transmission electron microscopy (TEM) and the nanoparticles are found to have a narrow size of 5.1 ± 0.5 nm with spherical morphology. Further, the nanoparticles were examined by energy dispersive x-ray (EDX) spectroscopy to identify the presence of elements and confirmed the existence of Cd and S in single nanoparticles. X-ray diffraction (XRD) analysis exhibited 2θ values corresponding to CdS nanocrystals. Fourier transform infrared spectroscopy (FTIR) provides the evidence for the presence of proteins as possible biomolecules responsible for the stabilization of the synthesized CdS nanoparticles.

Microbe-mediated synthesis of antimicrobial semiconductor nanoparticles by marine bacteria

Development of bio-mediated synthesis of CdS nanoparticles is one of the important fields in nanoparticles. The present investigation demonstrates the eco-friendly synthesis of cadmium sulfide nanoparticles using Enterococcus sp. (RMAA). The formation of an intense peak at 410 nm in the UV–Vis spectrum reveals the synthesis of CdS nanoparticles. The crystalline natures of the synthesized CdS nanoparticles were identified by X-ray diffraction assay. The scanning electron microscope analysis shows the formation of spherical-shaped CdS nanoparticles with a size range of about 50–180 nm. Fourier transform infrared spectrum shows that the synthesized CdS nanoparticles are capped with bimolecular compounds which are responsible for the reduction of cadmium sulfate to sulfide nanoparticles. The resulting CdS nanoparticles were tested for antibacterial activity using agar well diffusion method against the test cultures of Serratia nematodiphila, Escherichiacoli, Klebsiellaplanticola, Vibrio sp. and Planomicrobium sp. having good zone of inhibition. The fungicidal activity of CdS nanoparticles against pathogenic fungus Aspergillus niger and Aspergillus flavus produced a good zone of inhibition. The novel green chemistry approach is an eco-friendly and reliable process and suitable for large-scale production.

Facile green extracellular biosynthesis of CdS quantum dots by white rot fungus Phanerochaete chrysosporium

This study details a novel method for the extracellular microbial synthesis of cadmium sulfide (CdS) quantum dots (QDs) by the white rot fungus Phanerochaete chrysosporium. P. chrysosporium was incubated in a solution containing cadmium nitrate tetrahydrate, which became yellow from 12h onwards, indicating the formation of CdS nanocrystals. The purified solution showed a maximum absorbance peak between 296 and 298nm due to CdS particles in the quantum size regime. The fluorescence emission at 458nm showed the blue fluorescence of the nanoparticles. X-ray analysis of the nanoparticles confirmed the production of CdS with a face-centered cubic (fcc) crystal structure. The average grain size of the nanoparticles was approximately 2.56nm, as determined from the full width at half-maximum (FWHM) measurement of the most intense peak using Scherer's equation. Transmission electron microscopic analysis showed the nanoparticles to be of a uniform size with good crystallinity. The changes to the functional groups on the biomass surface were investigated through Fourier transform infrared spectroscopy. Furthermore, the secretion of cysteine and proteins was found to play an important role in the formation and stabilization of CdS QDs. In conclusion, our study outlines a chemical process for the molecular synthesis of CdS nanoparticles.

Wet Chemical Synthesis of Cadmium Sulphide Nanoparticles and its Characterization

Cadmium sulphide (CdS) nanoparticles were successfully prepared by wet chemical method using cadmium acetate and sodium sulphide as the cadmium and sulphide sources along with sodium citrate as the capping agent. The synthesized CdS nanoparticles were characterized by XRD, SEM in order to confirm the phase purity and morphology of the sample. CdS nanoparticles exhibit cubic structure, which was revealed by the XRD analysis.

Microwave-Assisted Synthesis of Cadmium Sulfide Nanoparticles: Effect of Hydroxide Ion Concentration

ABSTRACTCadmium sulfide nanoparticles were synthesized by a microwave-assisted route in aqueous dispersion. The cadmium sulfide nanoparticles showed an average diameter around 5 nm and a cubic phase corresponding to hawleyite. The aqueous dispersions of the nanoparticles were characterized by UV-Vis spectroscopy, luminescence analysis, transmission electron microscopy and X-ray diffraction. The addition of sodium hydroxide solutions at different concentrations causes a red-shift in the wavelength of the first excitonic absorption peak of the cadmium sulfide nanoparticles, indicating a reduction of the band gap energy. Besides, the intensity of the luminescence of the nanoparticle dispersions was increased. However, there is a threshold concentration of the hydroxide ion above which the precipitation of the cadmium sulfide nanoparticles occurs.

Rapid biosynthesis of cadmium sulfide (CdS) nanoparticles using culture supernatants of Escherichia coli ATCC 8739, Bacillus subtilis ATCC 6633 and Lactobacillus acidophilus DSMZ 20079T

Cell-associated biosynthesis of cadmium sulfide (CdS) nanoparticles has been reported to be rather slow and costly. In this study, we report on a rapid and low cost biosynthesis of CdS using culture supernatants of Escherichia coli ATCC 8739, Bacillus subtilis ATCC 6633 and Lactobacillus acidophilus DSMZ 20079T. The synthesis was performed at room temperature in the laboratory ambience and CdS nanoparticles were formed within 24 h. Ultraviolet (UV)–visible spectroscopy study revealed the buildup of absorption bands at 419.5, 381.5 and 362.5 nm for E. coli ATCC 8739, B. subtilis ATCC 6633 and L. acidophilus DSMZ 20079T, respectively for assisted synthesis of CdS nanoparticles. X-ray diffraction (XRD), transmission electron microscopy (TEM) and fluorescence spectral analyses were performed to ascertain the formation of CdS nanoparticles. Individual nanoparticles as well as few aggregates having the size of 2.5 to 5.5 nm were found. The process of extracellular and fast biosynthesis may help in the development of an easy and eco-friendly route for the synthesis of CdS nanoparticles.

CdS-containing nano-assemblies of double hydrophilic block copolymers in water

Two samples of poly(sodium(sulfamate-carboxylate)isoprene)-block-poly(ethylene oxide) copolymer (SCIEO-1 and SCIEO-2) differing in molecular weight and relative length of polyelectrolyte blocks have been used as templates for the synthesis of cadmium sulfide (CdS) nanoparticles in aqueous media. The double-hydrophilic copolymer SCIEO has very high 1D charge density, and its polymer chain structure mimics that of polysaccharide heparin. It is soluble in aqueous media, but the addition of cadmium acetate (Cd(Ac)2) to its aqueous solution causes the formation of micellar aggregates with Cd2+containing insoluble cores above the threshold Cd2+ concentration. The trapped Cd2+ ions can be chemically transformed to CdS nanoparticles. The stability of hybrid SCIEO/CdS micelles depends on the ratio of PEO-to-SCI lengths: it was found that the SCIEO-2 copolymer with sufficiently long PEO block behaves as an effective stabilizer for the synthesis of CdS nanoparticles embedded in micelles, while SCIEO-1 does not. The morphology of aggregates varies with the Cd-to-SCI ratios and ranges from spherical to mixture of spherical and necklace-like micellar aggregates. A number of experimental techniques including static and dynamic light scattering, fluorescence correlation spectroscopy, atomic force and transmission electron microscopy, UV-vis, and fluorescence spectroscopy were employed for the characterization of both CdS containing hybrid micelles and embedded CdS nanoparticles.

MS2 Bacteriophage as a Biotemplate for Semiconductor Nanoparticle Synthesis

AbstractIn this work, we demonstrate the synthesis of cadmium sulfide (CdS) nanoparticles in aqueous solution with MS2 bacteriophages as a biotemplate. Bionanofabrication methods offer unique opportunities for nanomaterials synthesis, where choice of biotemplate can influence the size, shape and function of the produced material. Synthesis reactions are carried out under mild aqueous conditions, and thus hazardous organic solvents, high temperature, and extreme pH can be avoided. The MS2 bacteriophage is a potential template system for bionanofabrication of nanoscale materials due to its size and inherent physical/chemical properties. MS2 capsid proteins can be genetically modified to incorporate functional groups and sequences. Also, genomic RNA in MS2 can be degraded or replaced with other oligonucleotide sequences and still form intact capsids. In this work, we use MS2 for bio-assisted synthesis of CdS nanoparticles and adjust the amount of RNA present in the template to assess biotemplate-nanomaterial property relationships. Produced nanoparticles were probed with several techniques including UV-Vis, photoluminescence and Hi-Res TEM. Optical techniques revealed that CdS nanoparticles with predicated fluorescent properties form in the presence of MS2 and remain stable in aqueous solutions. In fact, MS2-templated CdS nanoparticles were stable at room temperature for several weeks. Presence of RNA in the capsid interior was found to have major impact on the biotemplating process. Hi-Res TEM micrographs verified the presence of nanocrystals and their association with the biotemplate. Bionanofabrication using viral templates holds promise to enable an efficient, controlled and environmentally sustainable synthesis approach for a range of important nanomaterials. The work presented here represents an additional step forward towards those goals.

Biosynthesis of cadmium sulfide nanoparticles by photosynthetic bacteria Rhodopseudomonas palustris

A simple route for the synthesis of cadmium sulfide nanoparticles by photosynthetic bacteria Rhodopseudomonas palustris has been demonstrated in this work. The cadmium sulfate solution incubated with R. palustris biomass changed to a yellow color from 48 h onward, indicating the formation of cadmium sulfide nanoparticles. The purified solution yielded the maximum absorbance peak at 425 nm due to CdS particles in the quantum size regime. Also, X-ray analysis of the purified nanoparticles confirmed the formation of cadmium sulfide. Transmission electron microscopic analysis of the samples showed a uniform distribution of nanoparticles, having an average size of 8.01 ± 0.25 nm, and its corresponding electron diffraction pattern confirmed the face-centered cubic (fcc) crystalline structure of cadmium sulfide. Furthermore, it was observed that the cysteine desulfhydrase producing S 2− in the R. palustris was located in cytoplasm, and the content of cysteine desulfhydrase depending on the growth phase of cells was responsible for the formation of CdS nanocrystal, while protein secreted by the R. palustris stabilized the cadmium sulfide nanoparticles. In addition, R. palustris was able to efficiently transport CdS nanoparticles out of the cell.

Synthesis of CdS nanocrystals stabilized with sodium citrate

The results on the study of the synthesis of cadmium sulfide nanoparticles in sodium citrate solutions using microwave radiation are presented. CdCl 2 and thioacetamide solutions were prepared with three different concentrations of sodium citrate, 2.0, 1.5 and 1.0 mM respectively, keeping constant a pH of 8, heating was carried out in a microwave oven for 60 s. Synthesis of nanoparticles were confirmed by different experimental techniques. The material was arranged as light sensitive cubic particles of nanometric size. Ultraviolet spectroscopy shows that the energy of the band gap is affected by the size of the particles. It was found that the size and aspect of the particles changed as a function of time when held at 86 °C.

Synthesis and properties of CdS nanoparticles in a polyethylene matrix

Nanocomposites of cadmium sulfide and high-pressure polyethylene have been synthesized. The mechanism of the thermal decomposition of thiourea complexes during the synthesis of cadmium sulfide nanoparticles has been investigated. The nanoparticle size, composition, and structure of the nanocomposites have been determined by x-ray diffraction, transmission electron microscopy, IR spectroscopy, and EXAFS spectroscopy, and the thermal decomposition of the nanomaterials has been studied.

Synthesis and spectral properties of starch capped CdS nanoparticles in aqueous solution

Synthesis of cadmium sulphide nanoparticles has been carried out in aqueous solution precipitation. Starch added during the synthesis of the nanoparticles resulted in cadmium-rich nanoparticles forming a stable complex with starch. The morphology and crystalline structure of such structures were measured by high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD), respectively. The grain size of the nanoparticles determined by these techniques was of the order of 5 nm, which correlates well with measurements performed by Raman scattering and photoacoustic spectroscopy.

A solid state nuclear magnetic resonance study on the thermolytic synthesis of CdS nanoparticles in a polystyrene matrix

We report on the optimization of the thermolytic synthesis of cadmium sulfide (CdS) nanoparticles in a polystyrene (PS) matrix. The annealing conditions were tuned on the basis of the indications coming from solid state 113Cd and 13C Nuclear Magnetic Resonance (NMR) experiments. 113Cd NMR provided direct evidence of CdS nanoparticles formation. Semi-quantitative 13C NMR experiments demonstrated that good quality samples are obtained by heating up precursor/polystyrene films to 270 °C in vacuum. X-ray diffraction (XRD) and wide angle X-ray scattering (WAXS) experiments revealed structural details of CdS nanoparticles, their average size ranging from 1 to more than 7 nm as a function of the annealing conditions.

Microbe Manufacturers of Semiconductors

Synthesis of cadmium sulfide (CdS) semiconductor nanoparticles within a prokaryotic organism is reported for the first time by Sweeney et al. This paper demonstrates the utility of microorganisms to perform chemistries outside the scope of their "normal" metabolism and offers an environmentally benign synthesis of CdS nanoparticles.