Green Synthesis of Stable Spherical Monodisperse Silver Nanoparticles Using a Cell-Free Extract of .

In the current study, a green method for the preparation of silver nanoparticles (AgNPs) is presented as an alternative to conventional chemical and physical approaches. A biomass of () fungus was used as a green and renewable source of reductase enzymes and metabolites, which are capable of transforming Ag ions into AgNPs with a small size (mainly 2-6 nm) and narrow size distribution (2-25 nm). Moreover, extracellular biosynthesis was carried out with a cell-free water extract (CFE) of , which allows for facile monitoring of the bioreduction process using UV-Vis spectroscopy and investigation of the effect of experimental conditions on the transformation of Ag ions into AgNPs, as well as the simple isolation of as-prepared AgNPs for the study of their size, morphology and antibacterial properties.

Effect of Exchangeable Ions in Natural and Modified Zeolites on Ag Content, Ag Nanoparticle Formation and Their Antibacterial Activity.

To broaden the application of silver nanoparticles (AgNPs), which are well-known antibacterial agents, they are supported on different substrates to prevent aggregation, increase their surface area and antibacterial efficiency, and to be separated from the system more effectively at the end of treatment. To produce nanocomposites that consist of silver nanoparticles on natural and modified zeolites, silver ions (Ag) were loaded onto zeolite (natural, Na-modified, H-modified) and then thermally reduced to AgNPs. The effect of the exchangeable cations in zeolite on Ag uptake, AgNPs formation, size and morphology was investigated by the TEM, SEM, EDX, XPS, UV-vis, XRD and BET methods.

Room-Temperature Synthesis of ZnS Nanoparticles Using Zinc Xanthates as Molecular Precursors.

Molecular precursors are suitable starting compounds for preparation of semiconductor nanoparticles (NPs), which allow for control of atomic ratio, composition, monodispersity, and particle size of nanoscaled metal sulfides/oxides. In the present study, we carried out a one-pot synthesis of ZnS NPs in aqueous triethanolamine medium at room temperature, from molecular precursor zinc xanthate as a source of both Zn and S ions. Furthermore, we compared the products obtained from zinc ethylxanthate (Zn(CHOCS)) and zinc amylxanthate (Zn(CHOCS)).

Preparation and Photocatalytic Properties of CdS and ZnS Nanomaterials Derived from Metal Xanthate.

In this paper, we report a new, simple method for the synthesis of CdS and ZnS nanoparticles (NPs) prepared in a basic aqueous medium using metal xanthate as the sulfur source. The structure, morphology, size distribution, optical band gap, and photocatalytic properties of the newly obtained nanomaterials were investigated by UV-Vis spectroscopy, X-ray diffraction, and transmission electron microscopy. The results show that both CdS and ZnS crystallized in cubic phase and formed NPs with average sizes of 7.

Kinetics of heavy metal ions removal by use of natural zeolite.

Kinetics of the uptake of cadmium, lead, copper, nickel and zinc ions from single ion solutions and from their mixture by zeolitic rock has been studied. Removal of ions obeyed the kinetic equation for adsorption. Corresponding adsorption constants and distribution coefficients were determined for each metal ion uptake from single ion solution or mixture.