Synthesis and Characterization of Ag-PILC Through the Formation of Ag@Montmorillonite Nanocomposite

NANO ◽  
2015 ◽  
Vol 10 (02) ◽  
pp. 1550031 ◽  
Author(s):  
Feng Rao ◽  
Shaoxian Song ◽  
Alejandro Lopez-Valdivieso

Ag pillared interlayered clays ( Ag -PILCs) were synthesized through a novel method, in which Ag nanoparticles were formed in montmorillonite interlayers. In this method, silver ions were first exchanged into montmorillonite interlayers, and then reduced into Ag nanoparticles by trisodium citrate at 100°C in aqueous solutions. The synthesized Ag @montmorillonite nanocomposite was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and its surface area was evaluated by using Brunauer–Emmet–Teller (BET) method. Compared to traditional PILCs synthesized through ion exchange method, the formed Ag -PILCs had better thermal stability and stronger structure because their pillars are nanoparticles. Furthermore, this method introduces a possibility to control the size of the pillars and thus the pore size of the PILCs, due to that the nanoparticle pillars can be modified on their forms and diameters in the synthesizing process. Also, it was found that the intercalating Ag nanoparticle pillars were formed at restricted pH values and silver ion concentrations.

1996 ◽  
Vol 454 ◽  
Author(s):  
Marc J. Ledoux ◽  
Cuong Pham-Huu ◽  
Christophe Bouchy ◽  
Pascal Del Gallo ◽  
Claude Estournes ◽  
...  

ABSTRACTHigh surface area (> 100 m2 · g−1) SiC doped with zirconium was prepared by the gas-solid reaction. The material was made up of three phases: β-SiC, covered by ZrO2 and an amorphous phase composed of Si, Zr and O. The characterization of the sample was performed by means of powder X-ray diffraction (XRD), surface area and porosity measurements by the BET method, scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). Preliminary catalytic tests, the standard n-C7 isomerization on supported MoOxCy showed that this new support was at least as effective as pure SiC.


2009 ◽  
Vol 1217 ◽  
Author(s):  
Vinodkumar Etacheri ◽  
Reenamole Georgekutty ◽  
Michael K Seery ◽  
Suresh C Pillai

AbstractSilver nanoparticles having different size and plasmon resonances were synthesized through a single step aqueous based method. The current procedure was based on the reduction of silver ions by ascorbic acid in the presence of sodiumborohydride and trisodium citrate. Triangular colloidal nanoparticles having different plasmon resonances (and hence different size and colours) were synthesized by varying only the concentration of ascorbic acid. These nanoparticles were found to be stable without using any surfactants or polymers. This study revealed a strong correlation between particle growth and concentration of constituent chemicals. Crystallinity and phase purity of the silver samples were investigated through powder X-ray diffraction studies (XRD). Absorption spectra of various silver particles were recorded using UV/Vis/NIR spectrometer. Morphological analysis was performed using transmission electron microscopy (TEM) and average edge lengths of nanoparticles were also calculated.


2007 ◽  
Vol 121-123 ◽  
pp. 123-126 ◽  
Author(s):  
Z.Y. Li ◽  
Hui Min Huang ◽  
C. Wang

The carbon-nanofibers carrying Ag nanoparticles (Ag/CNF) have been successfully obtained via electrospinning followed by calcination. For it, AgNO3/polyacrylonitrile (PAN) fibers were firstly prepared as an intermediate and then the intermediate was calcined at 600°C for 4h to transit the PAN nanofibers to the CNF and reduce AgNO3 to the Ag nanoparticles. Transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were used to characterize their morphologies and structures. The results show that the diameters of the Ag nanoparticles and CNF are 5 nm and 180 nm on the average, respectively. Most of the Ag nanoparticles were located on the surface of carbon nanofibers.


2015 ◽  
Vol 60 (2) ◽  
pp. 1159-1163 ◽  
Author(s):  
Ri Yu ◽  
Jiyeon Yun ◽  
Yoojin Kim

Abstract In this work is described a means of improving the chemical stability of Cu2O@SiO2, Cu2O@SnO2 and Cu2O@TiO2 materials. The SiO2, SnO2 and TiO2 coated samples were stable from pH 3 to pH 10 for up to seven days. To determine the stability of the coated nanoparticles, and their colloidal solutions under acidic and basic conditions, colloidal nanoparticle solutions with various pH values were prepared and monitored over time. Details of the effect of variations in pH on the phase stability of core-shell type Cu2O were characterized using transmission electron microscopy and X-ray diffraction.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Zahra Ghasemi ◽  
Habibollah Younesi

Nanozeolite NaA was synthesized by the hydrothermal method with silica extracted from rice husk as silica source. Amorphous silica with 87.988 wt%  SiO2was extracted from rice husk ash by a suitable alkali solution. The effect of the crystallization time and the ratio ofNa2O/SiO2on the properties of the final product was investigated. The synthesized nanozeolite was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) techniques, and Brunauer-Emmett-Teller (BET) method. Results revealed that the crystallization time and alkalinity have significant effects on the structural properties of nanozeolite. Nanocrystals NaA with crystal sizes ranging from 50 to 120 nm were synthesized at room temperature with 3 days aging, without adding any organic additives.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.


2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.


2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.


2017 ◽  
Vol 8 ◽  
pp. 1257-1265 ◽  
Author(s):  
Urszula Klekotka ◽  
Magdalena Rogowska ◽  
Dariusz Satuła ◽  
Beata Kalska-Szostko

Ferrite nanoparticles with nominal composition Me0.5Fe2.5O4 (Me = Co, Fe, Ni or Mn) have been successfully prepared by the wet chemical method. The obtained particles have a mean diameter of 11–16 ± 2 nm and were modified to improve their magnetic properties and chemical activity. The surface of the pristine nanoparticles was functionalized afterwards with –COOH and –NH2 groups to obtain a bioactive layer. To achieve our goal, two different modification approaches were realized. In the first one, glutaraldehyde was attached to the nanoparticles as a linker. In the second one, direct bonding of such nanoparticles with a bioparticle was studied. In subsequent steps, the nanoparticles were immobilized with enzymes such as albumin, glucose oxidase, lipase and trypsin as a test bioparticles. The characterization of the nanoparticles was acheived by transmission electron microscopy, X-ray diffraction, energy dispersive X-ray and Mössbauer spectroscopy. The effect of the obtained biocomposites was monitored by Fourier transform infrared spectroscopy. The obtained results show that in some cases the use of glutaraldehyde was crucial (albumin).


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