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.

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 Effects of Reaction Temperature on the Photocatalytic Activity of TiO2 with Pd and Cu Cocatalysts

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 966
Author(s):  
Yu-Wen Chen ◽  
Yu-Hsuan Hsu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Reaction Temperature ◽  
Uv Light ◽  
Quantum Effect ◽  
Electron Hole ◽  
Transmission Electron ◽  
N2 Sorption

The aim of this study was to investigate the effects of reaction temperature on the photocatalytic activity of TiO2 with Pd and Cu cocatalysts. N2 sorption, transmission electron microscopy and high-resolution transmission electron microscopy were used to characterize the specific surface area, pore volume, pore size, morphology and metal distribution of the catalysts. The photocatalytic destruction of methylene blue under UV light irradiation was used to test its activity. The concentration of methylene blue in water was determined by UV-vis spectrophotometer. Pd/TiO2 catalyst was more active than Cu/TiO2 and TiO2. At 0–50 °C reaction temperature, the activity of TiO2 and Pd/TiO2 increased with an increase of reaction temperature. When the temperature was as high as 70 °C, the reaction rate of TiO2 drop slightly and Pd/TiO2 became less effective. In contrast, Cu/TiO2 was more active at room temperature than the other temperatures. The results indicate that the photocatalytic activity of the catalyst is influenced by the reaction temperature and the type of cocatalyst. When the reaction temperature is higher than 70 °C, the recombination of charge carriers will increase. The temperature range of 50–80 °C is regarded as the ideal temperature for effective photolysis of organic matter. The effects of reaction temperature mainly influence quantum effect, i.e., electron-hole separation and recombination.

CHARACTERIZATION AND ELECTRICAL PROPERTIES OF ALIGNED CARBON NANOTUBES WITH HIGH ASPECT RATIO

2011 ◽  
Vol 10 (01n02) ◽  
pp. 23-28
Author(s):  
RAVI BHATIA ◽  
V. PRASAD ◽  
M. REGHU
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Aspect Ratio ◽  
Multiwall Carbon Nanotubes ◽  
High Quality ◽  
Transmission Electron Microscopy Analysis ◽  
Transmission Electron ◽  
Electron Microscopy Analysis ◽  
High Degree

High-quality multiwall carbon nanotubes (MWNTs) were produced by a simple one-step technique. The production of MWNTs was based on thermal decomposition of the mixture of a liquid phase organic compound and ferrocene. High degree of alignment was noticed by scanning electron microscopy. The aspect ratio of as-synthesized MWNTs was quite high (more than 4500). Transmission electron microscopy analysis showed the presence of the catalytic iron nanorods at various lengths of MWNTs. Raman spectroscopy was used to know the quality of MWNTs. The ratio of intensity of the G-peak to the D-peak was very high which revealed high quality of MWNTs. Magnetotransport studies were carried out at low temperature and a negative MR was noticed.

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

scholarly journals Oxide-Clay Mineral as Photoactive Material for Dye Discoloration

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 132
Author(s):  
Maicon O. Miranda ◽  
Bartolomeu Cruz Viana ◽  
Luzia Maria Honório ◽  
Pollyana Trigueiro ◽  
Maria Gardênnia Fonseca ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Clay Mineral ◽  
Uv Light ◽  
High Photocatalytic Activity ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Zirconium Oxides ◽  
Transmission Electron ◽  
Palygorskite Clay

Titanium and zirconium oxides (TiO2 and ZrO2, respectively) were obtained from alkoxides hydrolyses, and then deposited into palygorskite clay mineral (Pal) to obtain new materials for photocatalytic applications. The obtained materials were characterized by structural, morphological, and textural techniques. X-ray diffraction (XRD) results confirmed the characteristic peaks of oxides and clay transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images of the modified palygorskite with both oxides showed that the clay was successfully modified by the proposed method. The increase in the specific surface area of the clay occurred when TiO2 and ZrO2 were deposited on the surface. The photocatalytic activity of these materials was investigated using the Remazol Blue anion dye under UV light. The evaluated systems presented high photocatalytic activity, reaching approximately 98% of dye discoloration under light. Thus, TiO2–Pal and ZrO2–TiO2–Pal are promising clay mineral-based 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.

Fabrication of Microcrystalline Cellulose/CdS Nanocomposites and their Photocatalytic Properties

2013 ◽  
Vol 634-638 ◽  
pp. 2475-2480
Author(s):  
Ai Min Tang ◽  
Ting Ting Hu ◽  
Xia Su
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Microcrystalline Cellulose ◽  
Uv Light ◽  
Absorption Spectrometry ◽  
Cds Nanoparticles ◽  
Ultrasound Wave ◽  
Transmission Electron ◽  
Initial Ph ◽  
Cds Nanocomposites

Microcrystalline cellulose (MCC)/cadmium sulfide (CdS) nanocomposites were prepared by using ultrasound wave irradiation. The as-prepared samples were characterized using scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), atomic absorption spectrometry (AAS), transmission electron microscopy (TEM). The photocatalytic behavior of MCC/CdS nanocomposites was evaluated using the degradation of a methyl orange (MeO) aqueous solution under ultraviolet (UV) light irradiation. Results showed that CdS nanoparticles were evenly distributed on the surface of MCC with little aggregation; the amount of Cd attached to the MCC was 23.75 % (w/w, Cd/composites). The MeO degradation rate was much higher when the MCC/CdS nanocomposites were irradiated with UV light than when CdS powder alone was irradiated. In dark conditions, the MCC/CdS nanocomposites showed almost no photocatalytic activity. In addition, the amount of MCC/CdS nanocomposites added to MeO solution and the initial pH of the MeO solution were also important factors influencing the photocatalytic activity. The results show that MCC/CdS nanocomposites are promising materials with excellent performance in photocatalytic applications.

Hydrothermal Synthesis and Photocatalytic Properties of Flower-Like CdS Nanostructures

2011 ◽  
Vol 335-336 ◽  
pp. 460-463 ◽  
Author(s):  
Hong Mei Wang ◽  
Da Peng Zhou ◽  
Yuan Lian ◽  
Ming Pang ◽  
Dan Liu
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Sulfur Source ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Transmission Electron ◽  
Cds Nanostructures

Hexagonal flower-like CdS nanostructures were successfully synthesized through a facile hydrothermal method with thiourea as sulfur source. By combining the results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), the structural and morphological characterizations of the products were performed. The photocatalytic activity of CdS nanostructures had been tested by degradation of Rhodamine B (RB) under UV light compared to commercial CdS powders, which indicated that the as-syntherized CdS nanostructures exhibited enhanced photocatalytic activity for degradation of RB. The possible growth mechanism of CdS nanostructures was proposed in the end.

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.

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