Sharif Digital Repository

Lanthanum hydroxide (La(OH)3) nanostructures, including elliptical nanoparticles, octahedral rods and irregular nanoparticles were prepared chemically in NaOH and KOH solutions with 10 M concentration. The obtained powders were characterized with XRD, SEM, TEM and DTA. Crystallinities, morphologies and thermal behavior of the obtained nanostructure powders were investigated under the influence of above mentioned solvents. The effect of chemical's temperature was also determined in one of the solvents (i.e. NaOH). The formation of growth in nanostructure mechanism under the influence of alkali solutions (i.e., KOH and NaOH) have been discussed considerably in this paper  

In the present study, we performed hydrothermal method as a simple and efficient route for the synthesis of rutile TiO 2 nanostructures in various concentrations of lithium hydroxide solutions. TiO 2 nanopowders with average sizes of 15 and 23 nm were prepared using 4 M and 7 M LiOH solutions. X-ray diffraction analysis (XRD), transmission electron microscope (FEG-STEM), scanning electron microscopy (SEM), and Brunauer-Emmet-Teller (BET) analyses were used in order to characterize the obtained products and comparison of the morphology of the powders obtained in different concentrations of LiOH solvent. It was shown that alkali solution concentration has affected the crystallinity,... 

Three-dimensional (3D) bundles of self-assembled lanthanum hydroxide nanorods with average crystallite size of about 20 nm were fabricated via a facile and rapid microwave-assisted chemical route. The obtained material was characterized with X-ray diffractometry (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigations. The obtained nanorods have average diameter of about 115 nm and average length of about 730 nm. Self-assembly of primary La(OH)3 nanoparticles and their subsequent anisotropic growth along 〈2 0 0〉 direction, was proposed to be the mechanism for the formation of 3D bundles of nanorods, using TEM images. The thermal behavior of the... 

Rosette-like boehmite nanostructures were prepared successfully via a simple hydrothermal process. The obtained material was characterized with X-ray powder diffractometry (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Using Scherrer formula, the average crystallite size of the obtained boehmite rosettes was measured to be about 8 nm. It was shown that boehmite nanopetals with average width of about 41 nm determined by TEM, were formed during the hydrothermal process and then self assembled due to weak hydrogen bonds to fabricate boehmite rosettes. The specific surface area of the obtained rosette-like nanostructures was calculated through BET... 

Self-assembled dandelion-like hydroxyapatite (HAp) nanostructures were successfully synthesized via a mild template-free hydrothermal process, using ethylenediaminetetraacetic acid (EDTA) as the surfactant. The obtained dandelion-like HAp nanostructures were between 5 and 8 μm in diameter and were composed of radially oriented nanorods with an average diameter of about 200 nm. The X-ray diffraction analysis and Fourier transform infrared spectroscopy were used to characterize the crystalline phase and purity of the synthesized nanostructures. The Brunauer-Emmett-Teller surface area of the dandelion-like nanostructures was measured to be about 39 m2/g. The results of thermal analysis revealed... 

Galvanostatic method was used to electrodeposit Fe nanostructures on platinum electrodes as catalysts. Scanning electron microscopy (SEM) revealed flower-like Fe deposits with high surface area. Carbon nanotubes were grown on flower-like Fe nanostructures by chemical vapor deposition. The structure of the synthesized carbon nanotubes was investigated by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and X-ray diffraction. According to X-ray diffraction patterns, Fe was the only detected constituent of the deposited coating. The carbon nanotubes had small wall-thickness and wide hollow core