scholarly journals Bromate Removal from Water Using Doped Iron Nanoparticles on Multiwalled Carbon Nanotubes (CNTS)

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Aasem Zeino ◽  
Abdalla Abulkibash ◽  
Mazen Khaled ◽  
Muataz Atieh

The raw carbon nanotubes (CNTs) were prepared by the floating catalyst chemical vapor deposition method. The raw carbon nanotubes were functionalized, impregnated with iron nanoparticles, and characterized using high resolution transmission electron microscopy (HRTEM), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and thermogravimetric analysis (TGA). The three types of these multiwalled carbon nanotubes were applied as adsorbents for the removal of bromate from drinking water. The effects of the pH, the concentration ofBrO3-anion, the adsorbent dose, the contact time, and the coanions on the adsorption process have been investigated. The results concluded that the highest adsorption capacities were 0.3460 and 0.3220 mg/g through using CNTs-Fe and raw CNTs, respectively, at the same conditions. The results showed that the CNTs-Fe gives higher adsorption capacity compared with the raw CNTs and the functionalized CNTs. The presence of nitrate (NO3-) in the solution decreases the adsorption capacity of all CNTs compared with chloride (Cl-) associated with pH adjustment caused by nitric acid or hydrochloric acid, respectively. However, the adsorption of all MWNCTs types increases as the pH of solution decreases.

2009 ◽  
Vol 4 ◽  
pp. 45-64 ◽  
Author(s):  
Ho Jin Ryu ◽  
B.K. Singh ◽  
K.S. Bartwal ◽  
Iwan V. Kityk

Multiwalled carbon nanotubes (MWNTs) were fabricated by thermal chemical vapor deposition (CVD) using monometallic and bimetallic Co and Ni on MgO as the catalyst. The mixture of H2/C2H2 gas was used as carbon source. The prepared CNTs have different sizes/shapes and morphologies with minimal formation of carbon particles. The maximum yield of CNTs was obtained with 50% Co catalyst at 600 oC. The morphology of the CNTs with 50% Co loading generates curved structure while 50% Ni results in the formation of linear structure with aligned graphene walls. Intensity ratio of D and G-peaks (ID/IG) was measured from Raman spectra. Scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) was done for the structural analysis of the prepared MWNTs.


2016 ◽  
Vol 51 (16) ◽  
pp. 2291-2300 ◽  
Author(s):  
Shadpour Mallakpour ◽  
Samaneh Soltanian

Chemical functionalization of carboxylated multiwalled carbon nanotubes with vitamin B1 was carried out under ultrasonic irradiation. The functionalized nanotubes were embedded in a chiral and biodegradable poly(ester-imide) to prepare multiwalled carbon nanotubes reinforced polymer nanocomposites. Optically active poly(ester-imide) was synthesized by step-growth polymerization of aromatic diol and amino acid based diacid. The vitamin B1 functionalized multiwalled carbon nanotubes and the resulting nanocomposites were examined using Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, transmission electron microscopy, and field-emission scanning electron microscopy. Thermogravimetric analysis results indicated that temperature at 10% weight loss was increased from 409℃ for pure PEI to 419℃, 427℃, and 430℃ for nanocomposites containing 5%, 10%, and 15% functionalized multiwalled carbon nanotubes, respectively. The Fourier-transform scanning electron microscopy and transmission electron microscopy images exhibited that the functionalized multiwalled carbon nanotubes were separated individually and enwrapped by polymer chains.


2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Jing Liu ◽  
Chunli Guo ◽  
Xiaojian Ma ◽  
Changhui Sun ◽  
Fengxia Li ◽  
...  

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.


RSC Advances ◽  
2014 ◽  
Vol 4 (55) ◽  
pp. 28826-28831 ◽  
Author(s):  
B. M. Maciejewska ◽  
M. Jasiurkowska-Delaporte ◽  
A. I. Vasylenko ◽  
K. K. Kozioł ◽  
S. Jurga

In this study, the oxidation of multiwalled carbon nanotubes (MWCNTs) sonicated and/or refluxed in acids (H2SO4/HNO3) was investigated using a combination of high-resolution transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and ab initio computational methods.


NANO ◽  
2013 ◽  
Vol 08 (06) ◽  
pp. 1350063
Author(s):  
JINXIAN LIN ◽  
PAN WANG ◽  
YUYING ZHENG

A poly(pyrrolyl methane) (Poly[pyrrole-2, 5-diyl(4-methoxybenzylidane)], PPDMOBA)/multiwalled carbon nanotubes (MWNTs) composites are fabricated by in situ chemical polycondensation of pyrrole and 4-methoxybenzaldehyde on MWNTs. The structure, morphology, thermal stability and electrical property of the resulting composites are investigated via fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and a four-probe method. The electrochemical performance of the composites is determined in a three-electrode system using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. FTIR, FESEM and TEM confirm that the composites have been successfully prepared, and PPDMOBA is uniformly dispersed in MWNTs. Electrical conductivity of PPDMOBA/MWNTs composites is 1.39 S cm-1, which is significantly larger than that of pristine PPDMOBA. The specific capacitance and charge transfer resistance of the composites is 56 F g-1 (1 mA cm-2) and 0.3Ω, respectively.


Author(s):  
Stefania Sandoval ◽  
Gerard Tobias

We have employed fullerenes as versatile agents to “cork” the open tips of multiwalled carbon nanotubes (MWCNTs), and as promoting species for the release of the inorganic material filled within the nanotubes’ cavities. High Z element compounds, namely, PbI2, ZnI2, and CeI3, were chosen to easily determine the presence of the filler inside the hosting nanotubes by transmission electron microscopy (TEM). Fullerenes can isolate inorganic nanostructures confined within the hollow cavities of MWCNTs, which allows the removal of the external material remnant after the filling. Otherwise, taking advantage of the affinity of fullerenes with selected solvents, we have confirmed the ability of the C60 molecules to promote the displacement of the inorganic guest from the host. We propose two different strategies to trigger the release, employing vapor and liquid phase treatments. The first protocol involves annealing filled MWCNTs in presence of fullerenes (to obtain C60PbI2@MWCNTs) and the subsequent washing of the sample in ethanol under mild conditions. On the other hand, the simultaneous introduction of the C60 molecules and the liberation of the guest are produced by a single step wet procedure; the latter being potentially useful when materials that are not stable at high temperatures are employed for filling.


2010 ◽  
Vol 163 ◽  
pp. 88-92 ◽  
Author(s):  
Danuta Stróż ◽  
M. Nowak ◽  
M. Jesionek ◽  
Katarzyna Bałdys

This paper presents a brand new hybrid material on the nanometric scale: the antimony sulfoiodide (SbSI) within carbon nanotubes (CNTs). It was prepared in CNTs ultrasonically by using elemental antimony (Sb), sulfur (S) and iodide (I) in the presence of methanol under ultrasonic irradiation (34 kHz, 2.6 W/cm2). The sonochemical process was leaded for 3 hours at 323 K. The antimony sulfoiodide (SbSI) consisted in multiwalled carbon nanotubes (CNTs) were characterized high-resolution transmission electron microscopy (HRTEM). These investigations exhibit that the SbSI filling the CNTs has single-crystal structure in nature and in the form of multiwalled carbon nanotubes. The SbSI grown in CNTs are very promising materials for further investigations as well as for some industrial and medical applications.


2008 ◽  
Vol 22 (25) ◽  
pp. 2493-2501 ◽  
Author(s):  
HUN-SIK KIM ◽  
MINSUNG KANG ◽  
WON-IL PARK ◽  
DON-YOUNG KIM ◽  
HYOUNG-JOON JIN

Multiwalled carbon nanotubes (MWCNTs) were dispersed in various alcohols such as methanol, ethanol and isopropanol using ultrasonication. In order to disperse the MWCNTs in the alcohols, they were treated using a mixture of H 2 SO 4 and HNO 3 (3 : 1, vol/vol). The concentration of MWCNTs was approximately 0.03 wt.% and they formed a homogeneous dispersion in the alcohol solutions. The functional groups introduced on the surface of the MWCNTs during the acid treatment were characterized by Fourier transform-infrared spectroscopy and X-ray photoelectron spectroscopy. The dispersibility of the MWCNTs in the alcohols was characterized using atomic force microscopy, scanning electron microscopy and transmission electron microscopy. The stability of the MWCNT dispersions was also measured using a recently developed optical analyzer (Turbiscan).


2002 ◽  
Vol 17 (11) ◽  
pp. 2768-2770 ◽  
Author(s):  
P. Gu ◽  
J. H. Zhao ◽  
G. H. Li

Y-branching multiwalled carbon nanotubes with a bamboolike structure were grown by chemical vapor deposition from a C–H–N gas system when B2O3 and Ti was supplied. Transmission electron microscopy images reveal that these novel junctions contain a tube branched into two tubes with nearly the same diameter. In addition, the tube walls show perpendicularly stacked graphite planes, which take on a bamboolike structure. The influence of preparation conditions on the structure of these carbon nanotubes is discussed. This novel structure may offer promising application for nanotube-based composites.


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