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.

Preparation and Characterization of Multiwalled Carbon Nanotubes Deposited by Europium Hydroxide

2011 ◽  
Vol 418-420 ◽  
pp. 428-435
Author(s):  
Shao Ming Fang ◽  
Jia You Tang ◽  
Li Jun Gao ◽  
Li Ming Zhou
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
High Resolution ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Ph Value ◽  
Multiwall Carbon Nanotubes ◽  
Europium Nitrate ◽  
Multiwalled Carbon ◽  
X Ray

In this paper, europium hydroxide (Eu(OH)3) was introduced onto multiwall carbon nanotubes (MWCNTs) by the MWCNTs and europium nitrate (Eu(NO3)3•6H2O) on a mild conditions in the alkalescence solution. The influence of the different pH value on the product was analyzed. Characterizations of the products were performed using raman spectroscopy, X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high resolution thermal field emission scanning electron microscopy (FE-SEM), and high resolution transmission electron microscopy (HR-TEM). Those results indicated that oxygen-containing groups such as -OH, -C=O, and -COOH generated on the surface of the MWCNTs treated with nitric acid. Those functional groups can attract Eu, and provide the position to Eu(OH)3. When the pH value situation of the reaction is 7-8, the MWCNTs deposited by Eu(OH)3 were obtained. Furthermore, there is the weak interaction between Eu and the functional groups of the MWCNTs. In addition, the integrity of the MWCNTs was not damaged during the whole preparation.

Multiwalled Carbon Nanotubes Covered with Cobalt (II) Phthalocyanine by In Situ Synthesis and its Electrochemical Sensing Performance towards DA and UA

2014 ◽  
Vol 809-810 ◽  
pp. 43-52
Author(s):  
Hua Hua Wang ◽  
Nan Li ◽  
Kai Li ◽  
Yuan Bu ◽  
Wen Le Dai ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Simultaneous Detection ◽  
Thick Layer ◽  
Electrochemical Sensing ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Platinum Particles

Multiwalled carbon nanotubes (MWCNTs) as an excellent supporter covered with a thick layer of cobalt phthalocyanine (CoPc) were prepared by in-situ synthesis. Platinum particles were adopted to enhance the conductivity of CoPc-MWCNTs. The final nanocomposite Pt-CoPc-MWCNTs was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Strong aromatic π-π stacking between MWCNTs and CoPc made CoPc in-situ forming on MWCNTs. With homogeneous thickness of CoPc covered on the MWCNTs and Pt particles equally distributed, the nanocomposite was used as electrocatalyst. The electrochemical properties of the composite got researched by casting the dispersion of Pt-CoPc-MWCNTs on the glassy carbon electrode. Compared with other modified electrodes, Pt-CoPc-MWCNTs/GC electrode exhibited excellent electrochemical activity towards dopamine (DA) and uric acid (UA). Linear responses for DA and UA were obtained in the ranges of 5 to 170 μM and 5 to 100 μM, and limits of detection were 2.6 and 1.4 μM (S/N= 3), respectively. Simultaneous detection of DA and UA in the presence of ascorbic acid (AA) also displayed selective property, with no interference to each other.

Removal of Pb(II) and Cu(II) from aqueous solution using multiwalled carbon nanotubes/iron oxide magnetic composites

2011 ◽  
Vol 63 (5) ◽  
pp. 917-923 ◽  
Author(s):  
Jun Hu ◽  
Donglin Zhao ◽  
Xiangke Wang
Keyword(s):  
Carbon Nanotubes ◽  
Iron Oxide ◽  
Multiwalled Carbon Nanotubes ◽  
Sorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Precipitation Method ◽  
Multiwalled Carbon ◽  
Magnetic Composites ◽  
X Ray

Multiwalled carbon nanotubes (MWCNTs)/iron oxide magnetic composites (named as MCs) were prepared by co-precipitation method, and were characterised by scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) in detail. The prepared MCs were employed as an adsorbent for the removal of Pb(II) and Cu(II) ions from wastewater in heavy metal ion pollution cleanup. The results demonstrated that the sorption of Pb(II) and Cu(II) ions was strongly dependent on pH and temperature. The experimental data were well described by Langmuir model, and the monolayer sorption capacity of MCs was found to vary from 10.02 to 31.25 mg/g for Pb(II) and from 3.11 to 8.92 mg/g for Cu(II) at temperature increasing from 293.15 to 353.15 K at pH 5.50. The sorption capacity of Pb(II) on MCs was higher than that of Cu(II), which was attributed to their ionic radius, hydration energies and hydrolysis of their hydroxides. The thermodynamic parameters (i.e., ΔH0, ΔS0 and ΔG0) were calculated from temperature dependent sorption isotherms, and the results indicated that the sorption of Pb(II) and Cu(II) ions on MCs were spontaneous and endothermic processes.

Synthesis and Performance of Dopa-Modified Multiwalled Carbon Nanotubes

2012 ◽  
Vol 184-185 ◽  
pp. 1289-1293
Author(s):  
Lu Zhi Wang ◽  
Lin Yu ◽  
Xiao Ling Cheng ◽  
Jun He ◽  
Le Jia Lin ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Multiwalled Nanotubes ◽  
Mixed Acid ◽  
Transmission Electron ◽  
Ft Ir ◽  
And Performance

The Dopamine-modified multiwalled carbon nanotubes (MWNT-Dopa) were synthesized by chemical reaction between dopamine (Dopa) and multiwalled carbon nanotubes which oxidazed by mixed-acid (MWNT-COOH). The structure of MWNT-Dopa were analyzed by Fourier transform infrared spectroscopy (FT-IR), Thermogravimetric (TG), Transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) techniques and the dispersity of MWNT-Dopa were studied by Dispersion stability analyzer. The results show that dopamine has been grafted on multiwalled carbon nanotubes successfully, and a dopamine layer which wraps on the surface of multiwalled nanotubes make multiwalled nanotubes have outstanding dispersity in water.

scholarly journals Sulfonitric Treatment of Multiwalled Carbon Nanotubes and Their Dispersibility in Water

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2442 ◽  
Author(s):  
Hui Liu ◽  
Jianfeng Wang ◽  
Jiachen Wang ◽  
Suping Cui
Keyword(s):  
Carbon Nanotubes ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Oxidation Degree ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Scattering Measurements ◽  
Ft Ir

In this study, Multiwalled carbon nanotubes (MWCNTs) were oxidized by a mixture of sulfuric acid and nitric acid (V:V = 3:1) at 70 °C for 1, 2, and 4 h, respectively. The oxidized MWCNTs were characterized by N2 adsorption, Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), and Raman spectroscopy to determine the oxidation degree. The dispersion of the MWCNTs was investigated by UV-vis-NIR, SEM, and dynamic light scattering measurements. Results show that sulfonitric treatment increased the surface area and total pore volume and reduced the average pore diameter of MWCNTs. The treatment promoted the formation of oxidized species on the surface MWCNTs, as identified by FT-IR, TGA, and X-ray photoelectron spectroscopy measurements, and more oxygen-containing functional groups were generated when treatment time was extended. Moreover, a general relationship between oxidation degree and dispersibility of MWCNTs in water was established. UV-vis-NIR and dynamic light scattering measurements and SEM images revealed that MWCNTs with higher oxidation degree showed better dispersibility in water.

Synthesis and Characteristics of Hierarchical Nanostructure Fe3O4 Coated Multi-Walled Carbon Nanotubes

2014 ◽  
Vol 926-930 ◽  
pp. 258-261
Author(s):  
Jing Heng Deng ◽  
Kan Ping Yu ◽  
Jian Guo Xie
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Solvothermal Process ◽  
X Ray ◽  
Hierarchical Nanostructure ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

Hierarchical nanostructure Fe3O4/multi-walled carbon nanotubes (Fe3O4/MWCNTs) were prepared by solvothermal process using acid treated MWCNTs and iron acetylacetonate in ethylene glycol as reduction reagent. The materials were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET). The results showed that petal-like hierarchical Fe3O4 grew on MWCNTs and the Fe3O4 nanoparticles had diameters in the range of 55-110 nm. It was a facile approach to grow hierarchical nanoFe3O4.

Well-Crystallized SnO2 Nanocrystals Homogeneously and Intimately Coated on Multiwalled Carbon Nanotubes by a Simple Surfactant-Free Hydrothermal Method

2011 ◽  
Vol 686 ◽  
pp. 474-481 ◽  
Author(s):  
Y.Q. Guo ◽  
Rui Qin Tan ◽  
Z.Y. Cao ◽  
Wei Jie Song
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Hydrothermal Reaction ◽  
Ph Value ◽  
Ethanol Solution ◽  
Multiwalled Carbon ◽  
X Ray ◽  
In Situ Deposition

A simple approach to the in situ deposition of well-crystallized SnO2nanocrystals on the surface of multiwalled carbon nanotubes (MWCNTs) in the ethanol solution system of SnCl2 was presented in this paper. The well-crystallized SnO2nanocrystals with small and uniform crystal size (4~5 nm) can be tightly and homogenously coated on the outside surface of the MWCNTs entirely. The prepared nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and nitrogen BET measurements. It is found that the hydrothermal reaction plays an important role for the crystal growth of the SnO2nanocrystals on the surface of MWCNTs, and the crystallinity of the SnO2nanocrystals can be controlled by varying the pH value or the hydrothermal reaction time. It is found that a unique structure of leaf-like SnO2nanosheets hanging on the MWCNTs was obtained when using water as the solvent of SnCl2instead of ethanol. The gas sensing performance of the SnO2/MWCNTs nanocomposites was also investigated.

scholarly journals One-Step Route to Synthesize Multiwalled Carbon Nanotubes Filled with MgO Nanorods

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Jing Liu ◽  
Chunli Guo ◽  
Xiaojian Ma ◽  
Changhui Sun ◽  
Fengxia Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Transmission Electron Microscopy ◽  
Multiwalled Carbon Nanotubes ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Transmission Electron ◽  
Good Crystallinity ◽  
One Step ◽  
Walled Cnts

Multiwalled carbon nanotubes filled with MgO nanorods were synthesized through the reaction of ethanol and Mg powder in the presence ofTiO2at 400C°. X-ray powder diffraction indicated that the sample was composed of graphite and cubic MgO. Transmission electron microscopy studies showed that multi-walled CNTs with the outer diameters of 70–130 nm were filled with discontinuous MgO nanorods whose diameter was in the range of 25–40 nm. The ratios of the band intensities(ID/IG=0.67)in Raman spectrum implied that carbon nanotubes had good crystallinity. The influence of correlative reaction factors on the morphology of the sample and the possible formation mechanism were discussed.

scholarly journals Characterization of Silver Nanoparticles Obtained by a Green Route and Their Evaluation in the Bacterium of Pseudomonas aeruginosa

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 395 ◽  
Author(s):  
Juan Carlos Martínez Espinosa ◽  
Raúl Carrera Cerritos ◽  
Maria Antonieta Ramírez Morales ◽  
Karla Paola Sánchez Guerrero ◽  
Rocio Alejandra Silva Contreras ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Pseudomonas Aeruginosa ◽  
Silver Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Bacterial Resistance ◽  
Antimicrobial Effect ◽  
X Ray ◽  
Transmission Electron ◽  
Green Route

Metal nanoparticles are widely used in different areas such as biotechnology and biomedicine, for example in drug delivery, imaging and control of bacterial growth. The antimicrobial effect of silver has been identified as an alternative approach to the increasing bacterial resistance to antibiotics. Silver nanoparticles were synthesized by the green route using the Geranium extract as a reducing agent. The characterization was carried out by the techniques of UV-Vis spectrophotometry, transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray emitted photoelectron spectroscopy (XPS) and X-ray diffraction. Nanoparticle diameters between 15 and 50 nm were obtained and the interplanar spaces calculated from the electron diffraction pattern corresponding to a mixture of silver with 4H and FCC structures. To determine the minimum inhibitory concentration of silver nanoparticles (AgNPs) on the Pseudomonas aeruginosa bacteria (ATCC-27853), different concentrations of colloidal solution 0.36, 0.18, 0.09 and 0.05 μg/mL were evaluated as a function of the incubation time, measuring the inhibition halo and colony forming unit (CFU) during 0, 2 and 4 h of incubation. The minimum inhibitory AgNPs concentration (MIC) is 0.36 μg/mL at 0 h while the concentration of 0.18 μg/mL presents a total inhibition of the bacterium after 2 h. For the rest of the dilutions, gradual inhibitions as a function of time were observed. We evaluate the antibacterial effect of silver nanoparticles obtained by a green methodology in Pseudomonas aeruginosa bacteria. Finally, the colloidal nanoparticle solution can be an antibacterial alternative for different biomedical approaches.

Influence of Functionalization of Multi-Walled Carbon Nanotubes on the Properties of Ethylene Vinyl Acetate Nanocomposites

2008 ◽  
Vol 8 (4) ◽  
pp. 1913-1921 ◽  
Author(s):  
Jinu Jacob George ◽  
Rajatendu Sengupta ◽  
Anil K. Bhowmick
Keyword(s):  
Carbon Nanotubes ◽  
Vinyl Acetate ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Surface Defects ◽  
Ethylene Vinyl Acetate ◽  
Radial Breathing Mode ◽  
Multiwalled Carbon ◽  
Band Ratio ◽  
X Ray

Commercially available multiwalled carbon nanotubes (MWNT) were chemically modified by amine, acid and silane and their ethylene vinyl acetate (EVA) based nanocomposites were prepared. Unmodified and modified nanotubes were characterized by thermogravimetry, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. Early degradation of modified nanotubes from the thermogravimetry study proved the presence of functional groups on nanotube surface. Increase in D-band to G-band ratio and a shift in radial breathing mode peaks from the Raman spectra indicated the generation of surface defects due to functionalization and variation in van der Waals force of attraction between nanotube aggregates on modification. The unmodified nanotubes improved the tensile strength by 30% with 4 weight% of filler. Amine modification imparted further increase in strength due to the presence of functional groups on the nanotube surface and the subsequent better dispersion of the nanotubes in the polymer matrix. The silane treatment imparted maximum improvement in various properties of the nanocomposites. The nanotubes provided better thermal degradation stability and also higher thermal conductivity to virgin EVA. The results were well supported by the morphological as well as swelling study of the various samples.

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