Direct Synthesis of Bimetallic Nanoalloys from Corresponding Bulk Alloys

2013 ◽  
Vol 1546 ◽  
Author(s):  
Chi-Kai Lin ◽  
Tao Xu
Keyword(s):  
Ag Nanoparticles ◽  
Direct Synthesis ◽  
Water Soluble ◽  
Liquid Lithium ◽  
Proof Of Concept ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Bimetallic Alloy ◽  
Transmission Electron ◽  
Bulk Alloys

AbstractWe report a transformative, all inorganic method-based synthesis of supported bimetallic alloy nanoparticles. We use Pd3Ag as a proof of concept. The method involves breaking down bulk Pd3Ag alloy into the nanoparticles in liquid lithium, converting metallic Li to LiOH, transferring Pd3Ag nanoparticles/LiOH mixture onto non-water soluble supports, followed by leaching off the LiOH with water under ambient conditions. The size of the resulting Pd3Ag nanoparticles was found narrowly distributed around 2.3 nm characterized by transmission electron microscope (TEM). In addition, studies by X-ray diffraction (XRD) showed that the resulting Pd3Ag nanoparticles inherited similar structure as the starting bulk Pd3Ag.

Defect Reduction in Cd1-xZnxTe Epilayers on GaAs Substrates

1994 ◽  
Vol 299 ◽  
Author(s):  
Saket Chadda ◽  
Kevin Malloy ◽  
John Reno
Keyword(s):  
Threading Dislocation ◽  
Full Width ◽  
X Ray Diffraction ◽  
Defect Reduction ◽  
X Ray ◽  
Gaas Substrates ◽  
Transmission Electron ◽  
Threading Dislocation Density ◽  
Optimum Period ◽  
Bulk Alloys

AbstractCd0.91Zn0.09Te/CdTe multilayers of various period thicknesses were inserted into Cd0.955Zn0.045Te bulk alloys grown on (001) GaAs. The net strain of the multilayer on the underlying Cd0.955Zn0.045Te was designed to be zero. X-ray diffraction full width at half maximum (FWHM) was used as a means to optimize the period thickness of the multilayer. Transmission electron microscopy of the optimum period thickness samples demonstrated four orders of magnitude decrease in the threading dislocation density. Mechanism of bending by equi-strained multilayers is discussed.

The Fabrication of Multicolor Electrochromic Device Based on RGO/BOPP Using Ag Nanoparticles

2018 ◽  
Vol 926 ◽  
pp. 79-84
Author(s):  
Achanai Buasri ◽  
Suparak Ojchariyakul ◽  
Patinya Kaewmanechai ◽  
Waratchaya Eakviriyapichat ◽  
Vorrada Loryuenyong
Keyword(s):  
Ag Nanoparticles ◽  
Heating System ◽  
Localized Surface Plasmon ◽  
Electrochromic Device ◽  
X Ray Diffraction ◽  
Transparent Conductive Electrode ◽  
Step Voltage ◽  
Biaxially Oriented Polypropylene ◽  
Transmission Electron ◽  
Reduced Graphene

In this research, we focused on silver (Ag) nanoparticles that exhibit various colors on the basis of their localized surface plasmon resonance (LSPR). The effects of step-voltage parameters on the coloration of the Ag deposition-based electrochromic device were investigated. Further, we report the use of reduced graphene oxide (RGO)/biaxially oriented polypropylene (BOPP) as the transparent conductive electrode. RGO was synthesized directly from graphite under a microwave heating system. BOPP film was coated with RGO by drop-casting method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), electrical resistance measurements and cyclic voltammetry (CV). The SEM and TEM images exist as typical wrinkled structure, folded region, transparent, indicating these layers are exfoliated to a very large extent. Our results primarily indicate that the novel BOPP/RGO/Ag/RGO/BOPP configuration presents an easy and expeditious way of preparing the voltage-tunable multicolor electrochromic device. The electrochromic device can be switched from the transparent state to the black state and yellow state.

Facile synthesis of water-soluble graphene-based composite: Non-covalently functionalized with chitosan-ionic liquid conjugation

2016 ◽  
Vol 09 (03) ◽  
pp. 1650045 ◽  
Author(s):  
Pei-Ying Li ◽  
Kai-Yu Cheng ◽  
Xiu-Cheng Zheng ◽  
Pu Liu ◽  
Xiu-Juan Xu
Keyword(s):  
Electron Microscopy ◽  
Ionic Liquid ◽  
Chemical Reduction ◽  
Water Soluble ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Text Interaction

Chitosan-ionic liquid conjugation (CILC), which was prepared through the reaction of 1-(4-bromobutyl)-3-methylimidazolium bromide (BBMIB) with chitosan, was firstly used to prepare functionalized graphene composite via the chemical reduction of graphene oxide (GO). The obtained water soluble graphene-based composite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ultraviolet-visible (UV–Vis) spectroscopy and so on. CILC-RGO showed excellent dispersion stability in water at the concentration of 2.0 mg/mL, which was stable for several months without any precipitate. This may be ascribed to the electrostatic attraction and [Formula: see text]–[Formula: see text] interaction between CILC and graphene.

Synthesis of Ag Nanoparticles-Clinoptilolite Composite by Homogeneous and Heterogeneous Nucleation

2013 ◽  
Vol 755 ◽  
pp. 97-103 ◽  
Author(s):  
A. Ruíz-Baltazar ◽  
R. Esparza ◽  
R. Pérez ◽  
G. Rosas
Keyword(s):  
Silver Nitrate ◽  
Sodium Borohydride ◽  
Heterogeneous Nucleation ◽  
Ag Nanoparticles ◽  
Natural Zeolite ◽  
Colloidal Solution ◽  
Chemical Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

In this study, a natural zeolite clinoptilolite-type was impregnated through homogeneous and heterogeneous nucleation with silver nanoparticles. The synthesis of Ag nanoparticles was carried out by chemical reduction of silver nitrate (AgNO3) with sodium borohydride (NaBH4). In the case of homogeneous nucleation, colloidal solution of Ag nanoparticles at concentrations of 1, 2 and 4 parts per million was added and magnetically mixed with the porous material. With respect to heterogeneous nucleation, a solution of clinoptilolite and silver nitrate (0.01 M) was prepared and stirred; subsequently, the reduction of Ag was possible due to the addition of an aqueous solution of sodium borohydride. For the structural characterization, transmission electron microscopy (TEM), X-ray diffraction (XRD) and infrared spectroscopy (IR) techniques were carried out. The results were compared and discussed in both types of nucleation.

scholarly journals A Pd/MnO2 Electrocatalyst for Nitrogen Reduction to Ammonia under Ambient Conditions

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 802
Author(s):  
Chang Sun ◽  
Yingxin Mu ◽  
Yuxin Wang
Keyword(s):  
High Performance ◽  
High Efficiency ◽  
Pd Nanoparticles ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Hydrogen Electrode ◽  
Faradaic Efficiency ◽  
Transmission Electron ◽  
Alternative Approach ◽  
Supported Pd

Electrochemical ammonia synthesis, which is an alternative approach to the Haber–Bosch process, has attracted the attention of researchers because of its advantages including mild working conditions, environmental protection, and simple process. However, the biggest problem in this field is the lack of high-performance catalysts. Here, we report high-efficiency electroreduction of N2 to NH3 on γ-MnO2-supported Pd nanoparticles (Pd/γ-MnO2) under ambient conditions, which exhibits excellent catalytic activity with an NH3 yield rate of 19.72 μg·mg−1Pd h−1 and a Faradaic efficiency of 8.4% at −0.05 V vs. the reversible hydrogen electrode (RHE). X-ray diffraction (XRD) and transmission electron microscopy (TEM) characterization shows that Pd nanoparticles are homogeneously dispersed on the γ-MnO2. Pd/γ-MnO2 outperforms other catalysts including Pd/C and γ-MnO2 because of its synergistic catalytic effect between Pd and Mn.

scholarly journals Synthesis of Pure Brookite Nanorods in a Nonaqueous Growth Environment

Crystals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 562 ◽  
Author(s):  
Mahmoud Hezam ◽  
Saif M. H. Qaid ◽  
Idriss M. Bedja ◽  
Fahhad Alharbi ◽  
Mohammad Khaja Nazeeruddin ◽  
...  
Keyword(s):  
Water Soluble ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
One Pot ◽  
Growth Environment ◽  
Transmission Electron ◽  
Anatase Nanoparticles ◽  
Na Ions ◽  
Ti Complexes ◽  
Brookite Phase

Brookite TiO2 is the most difficult TiO2 polymorph to synthesize. The available methods in the literature to produce brookite nanostructures mostly use water-based techniques for the preparation of water-soluble Ti complexes first, followed by a hydrothermal growth of the brookite nanostructures. Besides its multi-step nature, achieving a single brookite phase and optimizing the aqueous growth environment are all issues to be hardly controlled. In this work, pure brookite TiO2 nanorods are synthesized using tetrabutyl titanate Ti(OBu)4 and Sodium Fluoride (NaF) as precursor materials in a simple non-aqueous one-pot solvothermal process. Alcoholysis of only Ti(OBu)4 in ethanol resulted in pure anatase nanoparticles, while the addition of NaF was essential to promote the growth of highly pure brookite nanorods. The phase purity is confirmed by X-Ray Diffraction, Raman Spectroscopy, and High-Resolution Transmission Electron Microscopy. The growth mechanism is explained according to the Ostwald’s step rule, where Na+ ions are anticipated to have a potential role in driving the growth process towards the brookite phase.

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
Keyword(s):  
Ag Nanoparticles ◽  
Silver Ions ◽  
Trisodium Citrate ◽  
X Ray Diffraction ◽  
Exchange Method ◽  
Ph Values ◽  
Transmission Electron ◽  
Bet Method ◽  
Novel Method

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.

Preparation of Novel Ag/Bacterial Cellulose Hybrid Nanofibers for Antimicrobial Wound Dressing

2010 ◽  
Vol 152-153 ◽  
pp. 1771-1774 ◽  
Author(s):  
Jia Zhi Yang ◽  
Ju Wei Yu ◽  
Dong Ping Sun ◽  
Xu Jie Yang
Keyword(s):  
Bacterial Cellulose ◽  
Ag Nanoparticles ◽  
Antimicrobial Agents ◽  
Chemical Reduction ◽  
Cellulose Nanofibers ◽  
Analytical Techniques ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
Hybrid Nanofibers ◽  
Transmission Electron

In this work, we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers (BCF) as template. Silver (Ag) nanoparticles with an average diameter of 1.5 nm were well dispersed on BC nanofibers via a simple in situ chemical-reduction between AgNO3 and NaBH4 at relatively low temperature. The bare BCF and as-prepared Ag/BCF hybrid nanofibers were characterized by a range of analytical techniques including transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV–vis absorption spectra (UV–vis). The results reveal that Ag nanoparticles were homogeneously precipitated on the BCF surface. The results indicate that Ag/BCF hybrid nanofibers are promising candidate materials for functional antimicrobial agents.

Crystallization of nanostructured cobalt hydroxide carbonate at ambient conditions: a key precursor of Co3O4

2016 ◽  
Vol 80 (6) ◽  
pp. 995-1011 ◽  
Author(s):  
J. González-López ◽  
Á. Fernández-González ◽  
A. Jiménez
Keyword(s):  
Transformation Process ◽  
Cobalt Hydroxide ◽  
Small Range ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Lamellar Crystal ◽  
X Ray ◽  
Platelet Morphology ◽  
Transmission Electron ◽  
Material Sciences

AbstractCrystals of Co2CO3(OH)2have been synthesized under ambient conditions, in contrast to hydrothermal methods reported previously. We have developed a simple but efficient methodology to obtain an initial amorphous phase that evolves to a crystalline cobalt hydroxide carbonate after one week of maturation. X-ray diffraction analysis indicates that this phase crystallizes in the space groupP21/a(a= 12.886(6),b= 9.346(3),c= 3.156(1) Å, β = 110.358(6)°). The platelet morphology of Co2CO3(OH)2agrees with its lamellar crystal structure. High-resolution transmission electron microscopy (HRTEM) reveals that each individual platelet is comprised of nanodomains disoriented with respect to their neighbours. The kinetics and the activation energy (Ea= 6.26 kJ mol–1) of the transformation process have been estimated using the rate constant method. The precipitation of solids leads to a decrease in the cobalt concentration in the solution (∼88%) reaching values of ∼150 ppm, which can be considered a successful reduction from the perspective of water quality. The calcination in air of the synthetized platelets produced exclusively Co3O4. The thermo-X-ray difraction results confirm that Co2CO3(OH)2is transformed over a small range of temperatures (225–235°C) into pure Co3O4. HRTEM images show that the lamellar nanomorphology is preserved in the Co3O4phase. Therefore, understanding the crystallization behaviour of Co2CO3(OH)2can help to minimize environmental problems caused by cobalt pollution and may facilitate the management of methods to obtain phases with specific nanomorphologies used widely in material sciences.

Growth and assembly of monodisperse Ag nanoparticles by exchanging the organic capping ligands

2009 ◽  
Vol 24 (2) ◽  
pp. 352-356 ◽  
Author(s):  
Chenhui Hao ◽  
Dingsheng Wang ◽  
Wen Zheng ◽  
Qing Peng
Keyword(s):  
Ag Nanoparticles ◽  
Transformation Process ◽  
Probable Mechanism ◽  
Oriented Attachment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Monodisperse Nanoparticles ◽  
Transmission Electron ◽  
Organic Capping ◽  
Capping Ligands

Nearly monodisperse Ag nanoparticles capped with octadecylamine were prepared by direct thermal decomposition of silver nitrate in octadecylamine. Then the “oriented attachment” assembly process of these monodisperse nanoparticles was exhibited by exchanging the organic capping ligands, and Ag short nanorods capped with dodecanethiol could be obtained as a result. The composition of Ag was analyzed by x-ray diffraction, and the morphological change from nanoparticle to short-nanorod was examined by transmission electron microscopy. Moreover, we also propose a probable mechanism for this transformation process.

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