Preparation of TiO2/CNTs Nanocomposite and its Photocatalytic Activity for Methyl Orange in Aqueous Solutions

2011 ◽  
Vol 130-134 ◽  
pp. 1539-1543
Author(s):  
Xuan Hui Zhang ◽  
Su Juan Hu ◽  
Shao Ping Tong ◽  
Yuan Cheng ◽  
Dan Chen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Aqueous Solutions ◽  
Average Diameter ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Hydrolysis Method ◽  
Transmission Electron ◽  
Supernatant Liquid

TiO2/CNTs nanocomposites with different Ti/C molar ratios were prepared by a sol-hydrolysis method at 368 K, using titanium tetrachloride as a precursor and nitrified carbon nanotubes as a support. The crystal phase, morphology and microstructure of the sample were characterized by X-ray Diffraction (XRD) and High-Resolution Transmission Electron Microscope (HRTEM). The photocatalytic activity of the samples was performed by methyl orange in aqueous solutions under UV light.The supernatant liquid of methyl orange during degradation was determined by using an UV-vis spectrophotometer (UV-vis). XRD results show that the crystal phases of the sample are composed of carbon nanotubes, anatase and rutile. HRTEM results show that the average diameter of oval titania is about 4.2 nm, and it decorates on the surface of carbon nanotubes uniformly. UV-vis results show that the photocatalytic activity of the TiO2/CNTs nanocomposite with the optimum Ti/C molar ratio is much higher than that of P25. These results indicate that a synergistic effect exists between titania and carbon nanotubes in the nanocomposite.

Tribological Behavior of Carbon Nanotubes as an Additive on Lithium Grease

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Alaa Mohamed ◽  
T. A. Osman ◽  
A. Khattab ◽  
M. Zaki
Keyword(s):  
Carbon Nanotubes ◽  
Arc Discharge ◽  
Average Diameter ◽  
Friction Reduction ◽  
Lithium Grease ◽  
X Ray ◽  
Transmission Electron ◽  
Boundary Film ◽  
Load Carrying ◽  
Worn Surface

Carbon nanotubes (CNTs) with 10 nm average diameter and 5 μm in length were synthesized by electric arc discharge. The morphology and structure of CNTs were characterized by high resolution transmission electron microscopy (HRTEM) and X-ray powder diffraction. The tribological properties of CNTs as an additive on lithium grease were evaluated with a four ball tester. The results show that the grease with CNTs exhibit good performance in antiwear (AW) and decrease the wear scare diameter (WSD) about 63%, decrease friction reduction about 81.5%, and increase the extreme pressure (EP) properties and load carrying capacity about 52% with only 1% wt. of CNTs added to lithium grease. The action mechanism was estimated through analysis of the worn surface with a scanning electron microscope (SEM) and energy dispersive X-ray (EDX). The results indicate that a boundary film mainly composed of CNTs, Cr, iron oxide, and other organic compounds was formed on the worn surface during the friction process.

Study on Photocatalytic Properties of Anatase Phase TiO2 Synthesized by Ultrasonic-Assisted Hydrolysis

2012 ◽  
Vol 573-574 ◽  
pp. 110-114 ◽  
Author(s):  
Jin Xia ◽  
Ri Ya Jin ◽  
Kai Xuan Guo ◽  
Si Jing Yang
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Uv Light ◽  
Anatase Phase ◽  
Ultrasonic Method ◽  
X Ray Diffraction ◽  
Hydrolysis Method ◽  
Titanium Tetra Isopropoxide ◽  
Ultrasonic Assisted ◽  
Ft Ir

Titanium dioxide powders were synthesized by ultrasonic-assisted hydrolysis reaction of titanium tetra-isopropoxide at the low-temperature. The samples were characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD). The photocatalytic activity of samples were investigated by the degradation of methyl orange under UV light radiation (6W, λ= 352nm) at room temperature. The results indicated that the products were mainly composed of high homogeneity anatase phases, and the methyl orange degradation rate can reach more than 90% under ultraviolet irradiation 180min. The photocatalytic activity of the samples prepared by ultrasonic method is higher than that of the samples prepared by conventional hydrolysis method.

scholarly journals Photocatalytic Improvement under Visible Light inTiO2Nanoparticles by Carbon Nanotube Incorporation

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Mathana Wongaree ◽  
Siriluk Chiarakorn ◽  
Surawut Chuangchote
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Sol Gel ◽  
Multiwall Carbon Nanotubes ◽  
High Specific Surface Area ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Calcination Temperatures ◽  
Photocatalytic Activities ◽  
Multiwall Carbon

Photocatalytic activity ofTiO2nanoparticles was successfully enhanced by addition of multiwall carbon nanotubes (MWCNT) to make CNT/TiO2nanocomposites by sol-gel method at ambient temperature. CNT treated by HNO3 : H2SO4treatment (1 : 3 v/v) was mixed withTiO2nanoparticles at various molar ratios and calcination temperatures. The optimal molar ratio of CNT : TiO2was found at 0.05 : 1 by weight. The optimal calcination condition was 400°C for 3 h. From the results, the photocatalytic activities of CNT/TiO2nanocomposites were determined by the decolorization of 1 × 10−5 M methylene blue (MB) under visible light. CNT/TiO2nanocomposites could enhance the photocatalytic activity and showed faster for the degradation of MB with only 90 min. The degradation efficiency of the MB solution with CNT/TiO2nanocomposite achieved 70% which was higher than that with pristineTiO2(22%). This could be explained that CNT preventsTiO2from its agglomeration which could further enhance electron transfer in the composites. In addition, CNT/TiO2nanocomposites had high specific surface area (202 m2/g) which is very promising for utilization as a photocatalyst for environmental applications.

Effect of KCl Addition upon the Photocatalytic Activity of Zinc Sulphide

2011 ◽  
Vol 318 ◽  
pp. 1-10
Author(s):  
Dipti Vaya ◽  
Abhilasha Jain ◽  
Savitri Lodha ◽  
V. K. Sharma ◽  
Suresh C. Ameta
Keyword(s):  
Photocatalytic Activity ◽  
Light Intensity ◽  
Zinc Sulphide ◽  
Molar Ratio ◽  
Eosin Y ◽  
Molar Ratios ◽  
Ph Concentration

In the present investigation the photocatalytic activity of zinc sulphide has been enhanced using KCl in different molar ratios. The progress of the reaction was monitored spectrophotometrically. The effect of various parameters like pH, concentration of dye, amount of semiconductor, light intensity etc. upon the rate of photocatalytic bleaching of eosin Y has been observed. The molar ratio of KCl: ZnS = 0.25 was found to be a most efficient mixture for bleaching of eosin Y. A tentative mechanism for the photocatalytic bleaching of the dye has also been proposed.

Effect of Co-Doped La3+/Halogen on Visible Light Photocatalytic Activity of TiO2

2011 ◽  
Vol 239-242 ◽  
pp. 1923-1928
Author(s):  
Qian Lin Chen ◽  
Yuan Wang ◽  
Chun Yan Zhong ◽  
Yu Guo
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Surface Area ◽  
Visible Light Photocatalytic Activity ◽  
Co Doping ◽  
Hydrolysis Method ◽  
Degradation Ratio ◽  
Co Doped ◽  
Visible Light Photocatalytic

La3+/halogen (F-, Cl-and Br-) co-doped TiO2was synthesized by alkoxide hydrolysis method. The prepared La3+/halogen TiO2photocatalysts with anatase phases and rutile phases were characterized with XRD, EDS, TEM and surface area analytic technology. Methyl orange was used as model pollutants to evaluate its visible light photocatalytic activity. The results showed that the co-doping of La3+and halogen ions improved the surface area of TiO2. Compared with 450°C and 650°C, La3+/Cl-and La3+/Br-co-doped TiO2calcined at 550°C exhibited much higher photocatalytic activity. The optimal doping ratio of La3+/F-, La3+/Cl-and La3+/Br-was 0.4, 0.6, and 0.5 ((wt%)/(wt%)), respectively. Moreover, the degradation ratio of methyl orange on La3+/halogen co-doped TiO2with the optimal ratio were all higher than the maximum degradation ratio on La3+, F-, Cl-and Br-doped TiO2prepared by the same method.

Synthesis, Characterization and Photocatalytic Activity of Nb-Doped TiO2 Nanoparticles

2012 ◽  
Vol 455-456 ◽  
pp. 110-114 ◽  
Author(s):  
Xuan Dong Li ◽  
Xi Jiang Han ◽  
Wen Ying Wang ◽  
Xiao Hong Liu ◽  
Yan Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Doped Tio2 ◽  
X Ray ◽  
Vis Spectroscopy

Nb-doped TiO2 powders with different concentrations of Nb have been synthesized by a sol-gel method and characterized by a series of technologies including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. The photocatalytic activity of Nb-doped TiO2 is evaluated by degradation efficiency of methyl orange in aqueous solution. The results indicate that the photocatalytic activity of Nb-doped TiO2 synthesized with a Nb/Ti molar ratio of 5% is higher than that of TiO2 under the visible light.

Cetyltrimethylammonium Bromide-Assisted Hydrothermal Synthesis of Mixed-Phase TiO2 Nanorod and its Photocatalytic Activity

2014 ◽  
Vol 918 ◽  
pp. 12-16 ◽  
Author(s):  
Bin Sun ◽  
Xiu Ling Xu ◽  
Guo Wei Zhou
Keyword(s):  
Photocatalytic Activity ◽  
Cetyltrimethylammonium Bromide ◽  
Removal Rate ◽  
Weight Fraction ◽  
Mixed Phase ◽  
Molar Ratio ◽  
Structure Directing Agent ◽  
Transmission Electron ◽  
Ultraviolet Light Irradiation ◽  
Degussa P25

TiO2nanorods were successfully fabricated via hydrothermal method using cetyltrimethylammonium bromide (CTAB) as the structure-directing agent. The synthesized samples were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), and field-emission scanning electron microscope (FESEM). The study showed that as-prepared samples were the mixed crystalline phase of rutile and brookite. The weight fraction of rutile and brookite in the mixed-phase were accurately tuned by changing the concentration of CTAB. The morphology of prepared samples was TiO2nanorods with the diameter of 2530 nm and the length of 80150 nm. The samples for degradation of papermaking wastewater under ultraviolet light irradiation showed better photocatalytic activity than the commercial Degussa P25. HRT-3 prepared from CTAB: TBT molar ratio of 0.48 exhibited the highest photocatalytic activity, achieving 47.2% CODcrremoval rate and 89.5% chroma removal rate under irradiation 12 h.

Preparation and Characterization of Cu Loaded TiO2 Nanotube Arrays and their Photocatalytic Activity

2011 ◽  
Vol 364 ◽  
pp. 377-381 ◽  
Author(s):  
Syazwani Mohd Zaki ◽  
Srimala Sreekantan
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Anatase Phase ◽  
Average Diameter ◽  
Photoelectron Spectra ◽  
Nanotube Arrays ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
Wet Impregnation ◽  
X Ray

This paper described the preparation of Cu loaded TiO₂ nanotube arrays. Firstly, TiO₂ nanotube arrays were formed by anodization. Afterwards, the formed nanotube arrays were incorporated with Cu by wet impregnation method. The soaking time and concentration were varied to obtain an optimum set of parameter for Cu incorporation in TiO₂ nanotubes. After anodization, all samples were annealed at 400°C for 4 hours to obtain anatase phase. The nanotube arrays were characterized by field emission scanning electron microscopy (FESEM), x-ray diffraction (XRD) and x-ray photoelectron spectra (XPS). An average diameter 63.02 nm and length 12.15µm were obtained for TiO₂ nanotubes. The photocatalytic activity of these nanotubes were investigated with methyl orange (MO) and the TiO₂ nanotube prepared in 0.01M of Cu (NO₃)₂ solution within 3 hours demonstrates the highest photocatalytic activity with 83.6% degradation of methyl orange. Keywords: copper doping, wet impregnation, photocatalytic activity

scholarly journals Effect of Carboxylic Functional Group Functionalized on Carbon Nanotubes Surface on the Removal of Lead from Water

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Muataz Ali Atieh ◽  
Omer Yehya Bakather ◽  
Bassam Al-Tawbini ◽  
Alaadin A. Bukhari ◽  
Faraj Ahmad Abuilaiwi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Functional Group ◽  
Multiwall Carbon Nanotubes ◽  
Chemical Properties ◽  
Average Diameter ◽  
Transmission Electron ◽  
Physical And Chemical ◽  
Multiwall Carbon ◽  
Carboxylic Functional Group

The adsorption mechanism of the removal of lead from water by using carboxylic functional group (COOH) functionalized on the surface of carbon nanotubes was investigated. Four independent variables including pH, CNTs dosage, contact time, and agitation speed were carried out to determine the influence of these parameters on the adsorption capacity of the lead from water. The morphology of the synthesized multiwall carbon nanotubes (MWCNTs) was characterized by using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) in order to measure the diameter and the length of the CNTs. The diameters of the carbon nanotubes were varied from 20 to 40 nm with average diameter at 24 nm and 10 micrometer in length. Results of the study showed that 100% of lead was removed by using COOH-MCNTs at pH 7, 150 rpm, and 2 hours. These high removal efficiencies were likely attributed to the strong affinity of lead to the physical and chemical properties of the CNTs. The adsorption isotherms plots were well fitted with experimental data.

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