γ -Al 2 O 3 nanoparticles have been synthesized by electrochemical method using a rectangular aluminum plate as the a node and aluminum plate as the cathode (counter electrode); both electrodes have the same shape and dimensions. TEM, and XRD have been used to characterize the nanoparticles. The results indicated that the size range of γ-Al 2 O 3 nanoparticles was (14-19) nanometers. Dealt with the studying of the effectiveness of the synthesized nanoparticles on the adsorption of cadmium ion from its aqueous solutions under different temperatures (10, 20, 30, 40, 50) • C, Also thermodynamic parameters (ΔS, ΔH, ΔG) were calculated. The equilibrium geometries of γ-Al 2 O 3 nanoparticles have been studied by Density function theory (DFT) using Gaussian 09 package program. The calculated highest-occupied molecular orbital energy (E HOMO ) is to be (-.04798 a.u) and the lowest-unoccupied molecular orbital energy (E LUMO ) is to be (0.05909 a.u). The calculated activation energy breakage γ-Al 2 O 3 -Cd was (35.529 kcal/ mole).

The article describes a new way to the synthesis of silver nanoparticles based on UV-irradiation energy. Our technique allows for producing high quality and clean nanoparticles. Moreover, our photolysis approach allows us to synthesis silver nanoparticles (Ag NPs) with very low cost and short time. The nanostructures were characterized using X-ray diffraction, transmission electron spectroscopy and UV-visible spectrometer. Most of the Ag NPs are shown to be a hexagonal shape and some of them are a spherical shape. The average size of nanoparticles was calculated to be around 20.23 nm. The morphology, size, and ion concentration of the synthesized Ag NPs determine their absorbance and transmittance at the UV region of spectrum. Silver's antimicrobial properties are well known and due to their antimicrobial activity, silver nanoparticles become more important. Therefore, our synthesized Ag NPs were used against Staphylococcus aureus (Gram-positive bacteria) and E. coli (Gram-negative bacteria). The results show that the nanoparticles at a concentration of 0.2 mg/ml demonstrated a high activity of antimicrobials, resulting in a good inhibition for both grams positive and negative bacteria. However, the effect of Ag NPs on gram-positive bacteria is higher than gram-negative bacteria.

No abstract

No abstract

Graphene and graphene-silver nanocomposites have been prepared by the Hummers modified method and chemical reduction process in a simple one-pot technique. The electronic microscopes (scanning and transmutation), have been used to diagnose morphology and topography of nanocomposites, and X-ray diffraction is used to characterize the structure of the nanocomposites. The results reveal that the silver nanoparticles were effectively composited onto the nanosheets of the graphene within the diameter of silver particles, ranging from 10 to 22 nanometers. In present study, the synthesized nanocomposites are used as an adsorbent for Cibacron Blue P-6B dye from its aqueous solutions through diverse temperatures (15, 25, 35, 45, and 55 ◦C). Additionally, the thermodynamic parameters (ΔS, ΔH, ΔG) and the order of the adsorption process were calculated.