Synthesis of Noble Metal/Carbon Nanotube Composites in Supercritical Methanol

2006 ◽  
Vol 6 (3) ◽  
pp. 691-697 ◽  
Author(s):  
Zhenyu Sun ◽  
Lei Fu ◽  
Zhimin Liu ◽  
Buxing Han ◽  
Yunqi Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Metal Nanoparticles ◽  
Noble Metal ◽  
Photoelectron Spectroscopy ◽  
Noble Metal Nanoparticles ◽  
Narrow Particle Size Distribution ◽  
Supercritical Methanol ◽  
X Ray ◽  
Metal Precursors ◽  
Nanotube Composites

A simple and efficient route has been employed to deposit noble metal nanoparticles (Pt, Ru, Pt–Ru, Rh, Ru–Sn) onto carbon nanotubes (CNTs) in supercritical methanol solution. In this method, the inorganic metallic salts acted as metal precursors, and methanol as solvent as well as reductant for the precursors. The as-prepared nanocomposites were structurally and morphologically characterized by X-ray diffraction spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy, and X-ray photoelectron spectroscopy analyses. It was demonstrated that the CNTs were decorated by crystalline metal nanoparticles with uniform sizes and a narrow particle size distribution. The size and loading content of the nanoparticles on CNTs could be tuned by manipulating reaction parameters. Furthermore, the formation mechanism of the composites was also discussed.

scholarly journals Morphology, Photocatalytic and Antimicrobial Properties of TiO2 Modified with Mono- and Bimetallic Copper, Platinum and Silver Nanoparticles

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1129 ◽  
Author(s):  
Izabela Wysocka ◽  
Ewa Kowalska ◽  
Jacek Ryl ◽  
Grzegorz Nowaczyk ◽  
Anna Zielińska-Jurek
Keyword(s):  
Photocatalytic Activity ◽  
Metal Nanoparticles ◽  
Noble Metal ◽  
Photoelectron Spectroscopy ◽  
Bimetallic Nanoparticles ◽  
Diffuse Reflectance Spectroscopy ◽  
Action Spectrum ◽  
Noble Metal Nanoparticles ◽  
Biocidal Activity ◽  
X Ray

Noble metal nanoparticles (NMNPs) enhanced TiO2 response and extended its activity under visible light. Photocatalytic activity of TiO2 modified with noble metal nanoparticles strongly depends on the physicochemical properties of NMNPs. Among others, the differences in the size of NMNPs seems to be one of the most important factors. In this view, the effect of the metal’s nanoparticles size, type and amount on TiO2 photocatalytic and biocidal activity was investigated. TiO2 modified with mono- and bimetallic nanoparticles of Pt, Cu and Ag were prepared using chemical and thermal reduction methods. Obtained nanocomposites were characterized using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and diffuse-reflectance spectroscopy (DR/UV-Vis) techniques. The photocatalytic activity was examined in 2-propanol oxidation and hydrogen generation processes. The mechanism of modified TiO2 excitation was evaluated in action spectrum measurements during phenol oxidation. A possibility of using less energy-consuming light sources as a set of light-emitting diodes (LEDs) selected based on action spectrum results was examined. It was found that the differences in NMNPs size were the result of the reduction method. Moreover, coupling with a second metal strongly affected and differentiated the photocatalytic and biocidal activity of the obtained TiO2-based photocatalysts.

Synthesis of Nanophase Noble Metal Systems Utilizing Porous Silicon

1996 ◽  
Vol 457 ◽  
Author(s):  
I. Coulthard ◽  
T. K. Sham
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Porous Silicon ◽  
Noble Metal ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Visible Range ◽  
X Ray ◽  
Metallic Salt ◽  
Scanning Electron

ABSTRACTApart from its well known ability to luminesce very intensely at room temperature in the visible range, porous silicon is also an effective reducing agent. We report the formation of several noble metal (Pd, Ag, Au, Pt) nanostructures by reductive dispersion of metal ions from aqueous solutions onto the surface of porous silicon. The nanophase systems produced by reductive deposition vary with the element deposited and the metallic salt utilized in the process. The resulting nanophase systems were studied using a variety of techniques including: scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and spectroscopie methods using synchrotron radiation.

scholarly journals Photoresponse from noble metal nanoparticles-multi walled carbon nanotube composites

2012 ◽  
Vol 101 (24) ◽  
pp. 241113 ◽  
Author(s):  
M. Scarselli ◽  
L. Camilli ◽  
L. Matthes ◽  
O. Pulci ◽  
P. Castrucci ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Metal Nanoparticles ◽  
Noble Metal ◽  
Noble Metal Nanoparticles ◽  
Multi Walled Carbon Nanotube ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites

scholarly journals Synthesis and Characterization of Silver Nanoparticle-Multiwalled Carbon Nanotube Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Dunieskys G. Larrude ◽  
Marcelo E. H. Maia da Costa ◽  
Fernando L. Freire
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Silver Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Silver Nanostructures ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Nanotube Composites ◽  
Sample Characterization ◽  
Silver Mirror Reaction

Multiwalled carbon nanotubes (MWCNTs) grown by spray pyrolysis have been decorated with silver nanoparticles prepared via the silver mirror reaction. Good dispersion of silver nanostructures was obtained on the surface of MWCNTs, resulting in an efficient and simple wet chemistry method for increasing the reactivity of the carbon nanotubes surfaces. High-resolution transmission electron microscopy showed the orientations of the crystallography planes of the anchored silver nanoparticles and revealed their size distribution. Raman spectroscopy results confirm that the composite material preserves the integrity of the MWCNTs. Scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were also employed for sample characterization.

scholarly journals Comparative Study on the Influence of Noble Metal Nanoparticles (Ag, Au, Pd) on the Photocatalytic Activity of ZnO NPs Embedded in Renewable Castor Oil Polymer Matrices

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3468
Author(s):  
Andreea L. Chibac-Scutaru ◽  
Viorica Podasca ◽  
Daniel Timpu ◽  
Violeta Melinte
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Metal Nanoparticles ◽  
Noble Metal ◽  
Castor Oil ◽  
Nanocomposite Films ◽  
Noble Metal Nanoparticles ◽  
Zno Nps ◽  
Urethane Dimethacrylate

Hybrid polymeric materials, due to the unique combination of properties that can be obtained by the convenient variation of organic and inorganic components, represent an attractive alternative for many applications, especially photocatalysis. Herein, we report the preparation of nanocomposite films containing functionalized ZnO nanoparticles, as well as in situ photogenerated noble metal nanoparticles (Ag, Au, Pd), for the achieving of materials with enhanced photocatalytic activity under visible light. The flexible free-standing nanocomposite films were synthesized by photopolymerization of a monomer mixture (silane castor oil urethane dimethacrylate and polypropylene oxide urethane dimethacrylate) in the presence of a Irgacure 819 photoinitiator. The efficiency of ZnO NPs functionalization was established by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis, while the polymer composites were characterized by UV-Vis spectroscopy, X-ray diffraction, transmission electron microscopy and scanning electron microscopy to evidence the formation, size and distribution of the nanoparticles inside the photocrosslinked matrix. To establish the photocatalytic capacity of nanocomposite films, the decomposition of various pollutants (methyl orange, phenol, metronidazole) was monitored under visible light irradiation, the best results being obtained for Au/ZnO film. Also, the advantage of immobilizing the catalysts in a polymeric support and its recycling ability without a significant decrease in photocatalytic efficiency was analysed.

X-ray synthesis of noble metal nanoparticles onto 2D and 3D graphene oxide supports

2020 ◽  
Vol 528 ◽  
pp. 146313
Author(s):  
Maria C. Molina Higgins ◽  
Sajjad Ghobadi ◽  
Jessika V. Rojas ◽  
Carlos E. Castano
Keyword(s):  
Graphene Oxide ◽  
Metal Nanoparticles ◽  
Noble Metal ◽  
Noble Metal Nanoparticles ◽  
Oxide Supports ◽  
X Ray ◽  
3D Graphene ◽  
2D And 3D

scholarly journals Silver and Gold Nanoparticles from Limnophila rugosa Leaves: Biosynthesis, Characterization, and Catalytic Activity in Reduction of Nitrophenols

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Van Thuan Le ◽  
Ngoc Nhu Quynh Ngu ◽  
Tan Phat Chau ◽  
Thi Dung Nguyen ◽  
Van Toan Nguyen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Metal Nanoparticles ◽  
Leaf Extract ◽  
Noble Metal Nanoparticles ◽  
Metallic Ions ◽  
Ftir Microscopy ◽  
X Ray ◽  
Silver And Gold Nanoparticles

This study describes a simple green method for the synthesis of Limnophila rugosa leaf-extract-capped silver and gold nanoparticles without using any expensive toxic reductant or stabilizer. The noble metal nanoparticles were characterized by Fourier transform infrared (FTIR) microscopy, powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray analysis (EDX), high-resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED), and dynamic light scattering (DLS) method. It has been found that the biosynthesized silver and gold nanoparticles are nearly spherical in shape with a mean particle size distribution of 87.5 nm and 122.8 nm, respectively. XRD and SAED patterns confirmed the crystalline nanostructure of the metal nanoparticles. FTIR spectra revealed the functional groups of biomolecules presented in the extract possibly responsible for reducing metallic ions and stabilizing formed nanoparticles. The biosynthesized metal nanoparticles have potential application in catalysis. Compared to previous reports, Limnophila rugosa leaf-extract-capped silver and gold nanoparticles exhibited a good catalytic activity in the reduction of several derivatives of nitrophenols including 1,4-dinitrobenzene, 2-nitrophenol, 3-nitrophenol, and 4-nitrophenol.

scholarly journals In-Situ Preparation of Three Types of Noble Metal Nanoparticles-Polyacrylonitrile Nanofibers (NM NPs-PAN NFs, M = Pt, Au, and Ag) Using Electrospinning Technique Assisted with Ultrasound Irradiation

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 19
Author(s):  
Gheffar Kh. Kara ◽  
Azadeh Tadjaordi
Keyword(s):  
Metal Nanoparticles ◽  
Noble Metal ◽  
Ultrasound Irradiation ◽  
Noble Metal Nanoparticles ◽  
Dimethyl Formamide ◽  
Preparative Synthesis ◽  
X Ray ◽  
Synthesis Strategy ◽  
Growth Phenomenon

In recent years, the many alluring methods to prepare inorganic-organic hybrid nanomaterials have garnered great interest. The in-situ growth phenomenon is the most straightforward way to form these compounds with multiply dimensions. Here in, we demonstrate the in-situ synthesis of noble metal nanoparticles-polyacrylonitrile nanofibers (M NPs-PAN NFs) using an electrospinning route. Synthesis includes two main paths in the presence of dimethyl formamide (DMF). In the first path, the M NPs were prepared from the precursor solution using an in-situ reduction route in the presence of ultrasound irradiation and DMF (as a solvent and weak reducing agent) at 60 °C for nine min. The mechanism of our second path exhibited that the polymer matrix solution (PAN/DMF) acts as an appropriate host solution for the MNPs, due to possessing a high contents of effectiveness groups. These groups not only anchor NM NPs tightly in PAN fibers via dipole-induced dipole interactions but also they stabilize metal nanoparticles by good bonding interaction with their surface atoms. After preparing all nanofibers, TEM images revealed that both M NPs and their related nanofibers have a particular and unique shape without agglomerated particles with different sizes. Field emission scanning electron microscopy (FESEM), x-ray diffraction (XRD), energy-dispersive x-ray spectroscopy (EDS), and Fourier-transform infrared (FT-IR) were also applied to verify the formation of all samples. In this report, we tried to present a preparative synthesis strategy to the preparation of nanofibers.

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