scholarly journals Enhancement of Photocatalytic Activity on TiO2-Nitrogen-Doped Carbon Nanotubes Nanocomposites

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Lingling Wang ◽  
Long Shen ◽  
Yihuai Li ◽  
Luping Zhu ◽  
Jiaowen Shen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Photocatalytic Activity ◽  
Organic Pollutant ◽  
Scanning Calorimetry ◽  
Nitrogen Doped ◽  
Photogenerated Electrons ◽  
Transmission Electron ◽  
Effective Transfer ◽  
Nitrogen Doped Carbon

TiO2-nitrogen-doped carbon nanotubes (TiO2-CNx) nanocomposites are successfully synthesized via a facile hydrothermal method. The prepared photocatalysts were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric and differential scanning calorimetry analyses (TGA-DSC). The results show that the TiO2nanoparticles with a narrow size of 7 nm are uniformly deposited on CNx. The photocatalytic activity of the nanocomposite was studied using methyl orange (MO) as a model organic pollutant. The experimental results revealed that the strong linkage between the CNx and TiO2played a significant role in improving photocatalytic activity. However, the mechanical process for CNx and TiO2mixtures showed lower activity than neat TiO2. Moreover, TiO2-CNx nanocomposites exhibit much higher photocatalytic activity than that of neat TiO2and TiO2-CNTs nanocomposites. The improved photodegradation performances are attributed to the suppressed recombination of electrons and holes caused by the effective transfer of photogenerated electrons from TiO2to CNx.

scholarly journals Preparation and Photocatalytic Properties of SnO2Coated on Nitrogen-Doped Carbon Nanotubes

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Lingling Wang ◽  
Long Shen ◽  
Luping Zhu ◽  
Haiying Jin ◽  
Naici Bing ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Photocatalytic Activity ◽  
Uv Light ◽  
Electron Hole ◽  
Chemical Route ◽  
Nitrogen Doped ◽  
Transmission Electron ◽  
Nitrogen Doped Carbon ◽  
High Degree

SnO2nanoparticles coated on nitrogen-doped carbon nanotubes were prepared successfully via a simple wet-chemical route. The as-obtained SnO2/CNx composites were characterized using X-ray powder diffraction, scanning electron microscopy, and transmission electron microscopy. The photocatalytic activity of as-prepared SnO2/CNx for degradation Rhodamine B under UV light irradiation was investigated. The results show that SnO2/CNx nanocomposites have a higher photocatalytic activity than pure SnO2and SnO2/CNTs nanocomposites. This enhanced photoresponse indicates that the photoinduced electrons in the SnO2prefer separately transferring to the CNx, which has a high degree of defects. As a consequence, the radiative recombination of the electron-hole pairs is hampered and the photocatalytic activity is significantly enhanced for the SnO2/CNx photocatalysts.

In Situ Filling of Fe/Ni Oxide Nanowire into Carbon Nanotubes Doped with Nitrogen in CH4/H2/Air Plasma

2011 ◽  
Vol 15 ◽  
pp. 51-56 ◽  
Author(s):  
Xin Wang ◽  
Ya Yu Wang ◽  
Wei Tao Zheng ◽  
Zan Wang
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Transmission Electron Microscopy ◽  
Chemical Vapor ◽  
Air Plasma ◽  
Catalyst Film ◽  
Metal Oxide Nanoparticle ◽  
Transmission Electron ◽  
Nitrogen Doped Carbon ◽  
Ni Oxide

Nitrogen-doped carbon nanotubes (N-CNTs) were synthesized using air as the nitrogen carrier gas and CH4 as the carbon source by plasma-enhanced chemical vapor deposition over a thin catalyst film of Fe50Ni50. Transmission electron microscopy and high resolution transmission electron microscopy measurements have indicated that the N-CNTs grew with a tip-type growth mode. When H2 was added to the CH4/air plasmas during the N-CNTs growth stage, it was found that Fe/Ni oxide nanowire was filled into the nanotube. However, without adding H2 in the CH4/air mixture plasma, only metal oxide nanoparticle was found on the tip of the N-CNT.

Nitrogen-Doped Carbon Nanotubes and Graphene Nanohybrid for Oxygen Reduction Reaction in Acidic, Alkaline and Neutral Solutions

2015 ◽  
Vol 30 ◽  
pp. 50-58 ◽  
Author(s):  
Ji Yue Liu ◽  
Zan Wang ◽  
Jing Yan Chen ◽  
Xin Wang
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Chemical Vapor ◽  
Electrochemical Measurement ◽  
Reduction Reaction ◽  
Neutral Medium ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

Nitrogen-doped carbon nanotubes (N-CNTs) have beenprepared on FeNi catalyst by plasma-enhanced chemical vapor deposition in amixture of N2, O2, and CH4. On the opened topof CNT, multi-layer graphene grown self-assembly was observed by transmissionelectron microscopy and high resolution transmission electron microscopy. Thenanohybrid film analyzed by scanning electron microscopy exhibited a porous and3D morphology and pyridinic and graphitic nitrogen structure confirmed by x-rayphotoelectron spectroscopy. Electrochemical measurement indicated that the filmfacilitated about three-electron transferpathway for oxygen reduction reaction in neutral medium and two-electronreductions in both alkaline and acidic solutions.

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
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Adsorption Capacity ◽  
Multiwalled Carbon Nanotubes ◽  
Iron Nanoparticles ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Scanning Calorimetry ◽  
Multiwalled Carbon ◽  
Transmission Electron

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.

Reinforcing Effects of Poly(D-Lactide)-g-Multiwall Carbon Nanotubes on Polylactide Nanocomposites

2015 ◽  
Vol 15 (10) ◽  
pp. 8086-8092 ◽  
Author(s):  
Jeong Hee Yang ◽  
Jae Yun Lee ◽  
In-Joo Chin
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Testing Machine ◽  
Multiwall Carbon Nanotubes ◽  
Hydroxyl Groups ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Polylactide (PLA) nanocomposites with multi-walled carbon nanotubes (MWNTs) grafted with poly(L-lactide) or poly(D-lactide) were prepared by solution casting, and their thermal and mechanical properties were evaluated. MWNTs containing hydroxyl groups were treated by ring-opening polymerization of either L-lactide or D-lactide. Fourier transform infrared spectroscopy confirmed that the MWNT surfaces had been modified by the PLLA or PDLA chains. The thermal properties were measured by differential scanning calorimetry and thermogravimetric analysis. The mechanical properties were examined using a universal testing machine. The morphology of the fractured surfaces of the PLA nanocomposites was observed by scanning electron microscopy and transmission electron microscopy. PDLA-g-MWNTs were dispersed more uniformly compared to PLLA-g-MWNTs in the PLA matrix. The incorporation of PDLA-g-MWNTs greatly improved the tensile strength of the nanocomposites regardless of the contents. Thermal analysis revealed different characteristics at specific composites depending on the type of modification.

Photocatalytic Activity of Nitrogen-Doped Mesoporous Carbon Spheres Supporting Anatase TiO2 Prepared by a Simple Two-Step Solvothermal Approach

NANO ◽  
2015 ◽  
Vol 10 (05) ◽  
pp. 1550076 ◽  
Author(s):  
Tianjiao Bi ◽  
Jiafeng Wan ◽  
Shilin Yang ◽  
Xiujuan Yu ◽  
Fangwei Ma
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Mesoporous Carbon ◽  
Carbon Spheres ◽  
X Ray Diffraction ◽  
Nitrogen Doped ◽  
Transmission Electron ◽  
Ft Ir ◽  
Light Excitation ◽  
Adsorption Desorption

Nitrogen-doped mesoporous carbon spheres (NMCSs) supporting anatase TiO 2 ( NMCSs – TiO 2) were prepared by a simple two-step solvothermal approach. The characterizations for the physicochemical properties of prepared samples under different solvothermal temperatures were carried out by X-ray diffraction (XRD) analyses, scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption–desorption (Brunauer–Emmett–Teller (BET) measurements), Fourier transform infrared (FT-IR) spectroscopy, Raman scattering and UV-Vis diffuse reflectance spectra, were combined in order to determine the crystal phase and grain size, shape, degree of mesoporous carbon incorporation, and nature of the resultant oxycarbide chemical bonding on the surface and in the bulk. The high relative photocatalytic activity of NMCSs – TiO 2 nanoparticle was evaluated through a study of the decomposition of phenol under visible-light excitation.

scholarly journals Using nitrogen-doped carbon nanotubes as a catalyst support for selective hydrogenation of cinnamaldehyde

2017 ◽  
Vol 20 (K1) ◽  
pp. 20-27
Author(s):  
Truong Huu Tri ◽  
Nguyen Dinh Lam
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Selective Hydrogenation ◽  
Photoelectron Spectroscopy ◽  
Catalyst Support ◽  
Chemical Vapor ◽  
Active Phase ◽  
Chemical Vapor Deposition Method ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

Nitrogen-doped carbon nanotubes (N-CNTs) has been applied in different areas for over two last decade thanks to their novel properties. In this work, N-CNTs were produced by using chemical vapor deposition method, this material was used as catalyst support for nanoparticles paladi (Pd) catalyst. The support and catalyst Pd/N-CNTs were characterized by several techniques including Raman spectrum, X-ray photoelectron spectroscopy (XPS), nitrogen adsorption - desorption isotherms (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The catalyst was tested for the selective hydrogenation of cinnamaldehyde (CAL), The result of this study shows that the catalyst Pd/N-CNTs exhibits a high selectivity towards the C=C bond, over 91% of hydrocinnamaldehyde (HCAL) obtained at about 70% of CAL conversion. The obtained results also show that the present nitrogen atoms in the carbon architecture and functional groups of oxygen in the N-CNTs material have altered the surface properties, as enhancing the dispersion and anchoring active phase on the surface of the support.

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