Nanosized ZnS Particles Research Articles

ZnS NPs enhanced Eu3+ photoluminescence in the sol-gel silica matrix

ZnS co-doped Eu3+ Silica matrices were fabricated by sol–gel route. The fabricated matrices were structurally characterized by XRD and EDX. Optical characterizations were performed by FTIR, UV–Vis Absorption as well as PL Spectroscopy. Structural characterizations show the presence of nanosized ZnS particles (ZnS NPs) embedded in the Eu3+ doped Silica matrix. The study reveals an enhancement in PL intensity with ZnS concentration owing to the structural modification of the Eu3+ environment in the host matrix as well as energy transfer from the ZnS NPs to Eu3+ ions. The observations are elucidated in the light of Judd Ofelt intensity parameters as well as radiative parameters.

Effect of ZnS nanoparticles on the Judd-Ofelt and radiative parameters of Sm3+ ions in sol-gel silica matrix

Sm3+ singly doped and Sm3+ co-doped with varying concentration of ZnS nanoparticles (ZnS NPs) in silica matrix were fabricated via sol-gel route and investigated by various structural, thermo-gravimetric and spectroscopic techniques. Structural characterizations were done by XRD, EDX, TEM and FTIR whereas thermo-gravimetric characterization was performed by TGA/DTG technique. The structural studies reveal the presence of nanosized ZnS particles in the amorphous silica matrix. Spectroscopic studies were performed through absorption, excitation, emission and decay spectra of the fabricated samples. The dependence of Judd-Ofelt and various radiative parameters of Sm3+ on the concentration of ZnS NPs in the studied matrix were evaluated. Significantly high value of Ω2 obtained for the present system reveals effective network modifying nature of the ZnS NPs. The PL behaviour showed strong concentration dependence on ZnS NPs and showed optimum for the ZnS concentration of 0.5 M. The emission transition 4G5/2 → 6H9/2 of Sm3+ corresponding to the red colour observed at 642 nm for silica matrix in the present study showed excellent radiative behaviour compared to other popular glass hosts. This indicates ZnS NPs co-doped Sm3+ sol-gel silica matrix to be a prospective candidate for laser and other optical device applications.

A new solid-phase nanoparticle FRET assays based on GO/CS/ZnS nanocomposite film and developed in sensing for bromonium ion

Composite thin films consisting of nano-sized ZnS particles dispersed in chitosan/GO films have been prepared by in-situ method. The films obtained were characterized by FTIR and UV–Vis spectroscopy. The ZnS nanoparticles with 90 nm in diameter were dispersed uniformly in the film matrix. Optical absorption peak due to the size of ZnS particles was observed around 350 nm. The fluorescence emission at 430 nm of the GO/CS/ZnS nanocomposite films is very sensitive to the presence of bromonium ion from aqueous solutions. New solid-phase nanoparticles FRET assays are firstly immobilized on the substrate and then interacted with functionalized acceptor molecules in the solution to trigger the FRET effect to detect Br–.

Graphene Transforms Wide Band Gap ZnS to a Visible Light Photocatalyst. The New Role of Graphene as a Macromolecular Photosensitizer

We report the assembly of nanosized ZnS particles on the 2D platform of a graphene oxide (GO) sheet by a facile two-step wet chemistry process, during which the reduced graphene oxide (RGO, also called GR) and the intimate interfacial contact between ZnS nanoparticles and the GR sheet are achieved simultaneously. The ZnS-GR nanocomposites exhibit visible light photoactivity toward aerobic selective oxidation of alcohols and epoxidation of alkenes under ambient conditions. In terms of structure-photoactivity correlation analysis, we for the first time propose a new photocatalytic mechanism where the role of GR in the ZnS-GR nanocomposites acts as an organic dye-like macromolecular "photosensitizer" for ZnS instead of an electron reservoir. This novel photocatalytic mechanism is distinctly different from all previous research on GR-semiconductor photocatalysts, for which GR is claimed to behave as an electron reservoir to capture/shuttle the electrons photogenerated from the semiconductor. This new concept of the reaction mechanism in graphene-semiconductor photocatalysts could provide a new train of thought on designing GR-based composite photocatalysts for targeting applications in solar energy conversion, promoting our in-depth thinking on the microscopic charge carrier transfer pathway connected to the interface between the GR and the semiconductor.

Studies on ZnS Nanoparticles Prepared in Aqueous Sodium Dodecylsulphate (SDS) Micellar Medium

ZnS, a large band gap material, is useful in electro-luminescence and optoelectronic devices. We herein report a method for preparation of nanosized ZnS particles in micellar medium of anionic surfactant sodium dodecylsulphate. The optical properties of the prepared ZnS nanoparticles have been studied by absorption and fluorescence methods. Electron microscopic characterization has evidenced triangular particles, an uncommon observation in the synthesis of nanomaterials. PVC membrane containing nano ZnS dispersions has been prepared and its response as Zn2+ ion-selective membrane has been reported.

Preparation and characterization of zinc sulfide nanoparticles under high-gravity environment

Nanosized ZnS particles were prepared under high-gravity environment generated by the rotating packed bed reactor (RPBR) using zinc nitrate solution and hydrogen sulfide gas as raw materials. The effects of experimental conditions such as reactant concentration, reaction temperature, rotating speed of the RPBR and aging time, on the preparation of nanosized ZnS particles were investigated. A set of suitable operating parameters (the aging time of 48 h, concentration of zinc nitrate of 0.1 mol/l, reaction temperature of 45 °C and rotating speed of the RPBR of 1500–1800 rotation/min) for the preparation of nanosized ZnS were recommended. Under these optimum conditions, well-dispersed ZnS nanoparticles was obtained. The crystal structure, optical properties, size and morphology of the product were also characterized by XRD, UV-Vis spectrophotometer, and TEM, respectively. Results indicate that the prepared ZnS has a good absorption for light in the wavelength range of 200–330 nm. XRD analysis also shows the prepared ZnS is in a sphalerite crystal phase. The process has great potential of commercialization.

Size tailoring of ZnS nanoparticles synthesized in reverse micelles and recovered by compressed CO 2

Nanosized ZnS particles were synthesized in bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelles and then recovered by dissolving compressed CO 2 into the micellar solution. The size of the obtained ZnS nanoparticles can be tailored in the range of 1–100 nm by varying the experimental conditions. The particles’ size decreases with increasing pressure of CO 2. The size of the particles recovered at 308.2 K is smaller than that of the particles recovered at 298.2 K. Stirring of the solution in the recovery process can reduce the particle size effectively. Increase in molar ratio of water to AOT ( w) results in an increase in the particle size. However, the effect of the concentration of AOT in the micellar solution on the size of the products is very limited.

Mechanochemical synthesis of ultrafine zinc sulfide particles

The synthesis of nano-sized ZnS particles by the mechanochemical solid-state reaction of ZnCl 2 and CaS has been investigated using X-ray diffraction, TEM and DTA measurements. Mechanical milling of ZnCl 2 and CaS resulted in the formation of ∼ 500 nm ZnS particles containing aggregates of 12 nm crystallites. The addition of 71 vol% CaCl 2 as a diluent to the reactants resulted in the formation of separated 16 nm particles of ZnS. Using mechanically alloyed CaS (10–50 nm particle size) enabled the synthesis of isolated ZnS particles 7–9 nm in size. The effects of milling time and subsequent annealing on particle size have also been investigated.

Preparation of Nanosized ZnS Particles in Emulsions

Preparation of Nanosized ZnS Particles in Emulsions

Preparation of Nanosized ZnS Particles in Emulsions

Preparation of Nanosized ZnS Particles in Emulsions

Preparation of nanosized ZnS particles in water/oil emulsions by microwave heating

Preparation of nanosized ZnS particles in water/oil emulsions by microwave heating