Preparation of ZnS/CdS composite nanoparticles by coprecipitation from reverse micelles using CO2 as antisolvent

Spectroscopic Study on CdS/Ni/KNbO3: Confirming Ni Effect to Photocatalytic Activity

Herein, we report the structural and photophysical properties of CdS/Ni/KNbO3 composites with a quantum yield for photocatalytic H2 generation that is CdS and Ni amount dependent. The nonstoichiometric KNbO3 (1:1.1) structure indicates the defect at the K site, which is Ni-occupied during its deposit process. It exhibits a tendency like a Ni-doped characteristic up to 0.1 wt % Ni and then forms a Ni cluster in case the Ni amount exceeds 0.1 wt %. The related structural and photophysical properties of CdS/Ni/KNbO3 are examined with Fourier transform infrared, X-ray diffraction, ultraviolet-visible absorption, and luminescence spectral analysis. It demonstrates the CdS/Ni/KNbO3 composites to be an efficient light conversion caused by efficient charge/electron transfer between KNbO3 and CdS via doped Ni. The photocatalytic activity of CdS/Ni/KNbO3 exhibits a CdS and Ni amount dependency. The best photocatalytic activity for H2 generation is obtained with 0.1 wt % Ni and 2.9 wt % CdS as it gradually declines with the excess Ni amount than 0.1 wt % caused by a formed Ni cluster.

Highly selective separation of dyes using compressed CO2 and spherical polyelectrolyte brushes

The process of PS-PAA brush adsorbs dyes selectively and separates the aggregation assisted by the compressed CO₂. With the help of NaCl solution, PS-PAA is regenerated and retains high adsorption capacity even after five times.

Fluorometric selective detection of fluoride ions in aqueous media using Ag doped CdS/ZnS core/shell nanoparticles

In this study, a fluorometric method based on Ag–CdS/Ag–ZnS core/shell nanoparticles is developed for fluoride ion detection.

Photochemical synthesis of size-tailored hexagonal ZnS quantum dots

ZnS quantum dots were synthetized at room temperature using a simple photochemical process involving ketyl radicals. Through the simple adjustment of reagent concentration, the method allows the control of nanoparticle size. Transmission electron microscopy confirmed that the nanomaterial adopts the hexagonal structure.

Recycling functional colloids and nanoparticles

The stability and separation of colloids and nanoparticles has been addressed in numerous studies. Most of the work reported to date requires high cost, energy intensive approaches such as ultracentrifugation and solvent evaporation to recover the particles. At this point of time, when green science is beginning to make a real impact, it is vital to achieve efficient and effective separation and recovery of colloids to provide environmental and economic benefits. This article explores recent advances in strategies for recycling and reusing functional nanomaterials, which indicate new directions in lean engineering of high-value nanoparticles, such as Au and Pd.

Interfacial self-assembled fabrication of petal-like CdS/ dodecylamine hybrids toward enhanced photoluminescence

We report a new available strategy for fabricating 2-dimensional petal-like CdS/dodecylamine (DDA) hybrids with enhanced photoluminescence (PL) by using a method of oil/water interfacial self-assembly. First, water-soluble CdS nanocrystals (NCs) were controllably prepared at the two-phase interface by injecting the Na2S solution into CCl4 phase. And then, the as-synthesized CdS NCs (ca. 4 nm) were transferred from the water to the CHCl3 phase under the direction of DDA. Finally, through the electrostatic interactions between the positively charged amino of DDA and the negatively charged the ligand of NCs surface, we have successfully fabricated petal-like CdS/DDA hybrids via the interfacial self-assembly between the as-synthesized CdS NCs and DDA. The properties of as-prepared CdS NCs and their hybrids were thoroughly investigated by ultraviolet-visible (UV-vis), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), photoluminescence (PL), scanning electron microscopy (SEM) measurements. We have found that these petal-like CdS/DDA hybrids after interfacial self-assembly exhibit good PL property and higher quantum yield.

Studies on the micropolarities of bmimBF4/TX-100/toluene ionic liquid microemulsions and their behaviors characterized by UV-visible spectroscopy

Ionic liquids (ILs), 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4), were substituted for polar water and formed nonaqueous microemulsions with toluene by the aid of nonionic surfactant TX-100. The phase behavior of the ternary system was investigated, and microregions of bmimBF4-in-toluene (IL/O), bicontinuous, and toluene-in-bmimBF4 (O/IL) were identified by traditional electrical conductivity measurements. Dynamic light scattering (DLS) revealed the formation of the IL microemulsions. The micropolarities of the IL/O microemulsions were investigated by the UV-vis spectroscopy using the methyl orange (MO) and methylene blue (MB) as absorption probes. The results indicated that the polarity of the IL/O microemulsion increased only before the IL pools were formed, whereas a relatively fixed polar microenvironment was obtained in the IL pools of the microemulsions. Moreover, UV-vis spectroscopy has also shown that ionic salt compounds such as Ni(NO3)2, CoCl2, CuCl2, and biochemical reagent riboflavin could be solubilized into the IL/O microemulsion droplets, indicating that the IL/O microemulsions have potential application in the production of metallic or semiconductor nanomaterials, and in biological extractions or as solvents for enzymatic reactions. The IL/O microemulsions may have some expected effects due to the unique features of ILs and microemulsions.