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Li G.,State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology
Applied Mechanics and Materials | Year: 2012

TiO 2/Fe 2O 3 nanocomposite was fabricated by a hydrolysis-precipitation approach, with TiCl 4 as precursor and Fe 2O 3 as support. The crystal phase, diameter and morphology of the sample particle were characterized by X-ray diffraction, transmission electron microscope. The results show that the samples are composed of haematite and rutile. The morphology and diameter of rutile particle, coating effect and weight percentages of haematite and rutile are related to the preparing temperature and molar ratio of Fe/Ti. The photocatalytic activity of the prepared photocatalyst was estimated in an aqueous solution at ambient temperature of 303K. The results imply that the photocatalytic activity of the sample is higher than that of phase pure rutile, related to Fe/Ti molar ratio and its preparing temperature. These results can be attribute to the microsturcture of the sample. A synergistic effect exists between titania and haematite in the nanocomposite. © (2012) Trans Tech Publications, Switzerland.


Li G.,State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology
Advanced Materials Research | Year: 2012

TiO 2/FeOOH nanocomposite was fabricated by a hydrolysis-precipitation approach, using TiCl4 as precursor and FeOOH as support. The crystal phase, diameter and morphology of the sample particle were characterized by X-ray diffraction, transmission electron microscope. The results show that the samples are composed of goethite and rutile. The morphology and diameter of rutile particle, the weight percentages of goethite and rutile, and the microstructure of the samples are related to its preparing temperature and molar ratio of Fe/Ti. The photo-absorption properties of the samples and support were measured by an UV-vis spectroscopy. The results show that the absorption ability of the nanocomposite for visible light is well than that of phase pure rutile. The photocatalytic activity of the nanocomposite as prepared was estimated by degradation of methyl orange (MO) under UV or visible light in an aqueous solution at 303 K. The results indicate that the photocatalytic degradation activity of the nanocomposite for MO is higher than that of phase pure rutile, and the photocatalytic property of the sample is related to its molar ratio of Fe/Ti and preparation temperature. This can be attributed to the microstructure of the nanocomposite, which can improve solar utilization and reduce the recombination rate of solar induced electron-hole pair. This implies that a synergistic effect exists between titania and goethite in the nanocomposite. © (2012) Trans Tech Publications, Switzerland.


Cheng Y.,Zhejiang University of Technology | Xie W.,Zhejiang University of Technology | Zhang X.,Zhejiang University of Technology | Chen D.,Zhejiang University of Technology | And 2 more authors.
Materials Science Forum | Year: 2013

In this thesis, TiO2-pillared montmorillonite was prepared by a sol-gel method. The sample was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that the crystal phase of the sample is composed of anatase and montmorillonite. The microstructure of the sample is still layered structure. Furthermore, the XRD results indicate that the interlayer distance of crystal plane (001) of the montmorillonite left-shift obviously. In other words, its interlayer distance increases obviously. The adsorptive ability of the sample was tested with industry wastewater, which containing Pb2+. The results indicate that the adsorptive rate of sample for lead (II) cationic is 99.9%. After analyzing with the interlayer space, it indicated that the increasing of the interlayer space is good for the adsorptive ability. And the adsorptive ability reached a maximum when the interlayer space was 1.339 nm. The TiO2-pillared montmorillonite absorbed Pb2+ saturatedly was impregnated into nitric acid solution to dissolve the lead cationic. The results show that the concentration of the nitric acid is higher, the leaching rate of the lead cationic is higher. And it reached a maximum when the concentration of the nitric acid is 2 mol/L after leaching for 20 min.Introduction © (2013) Trans Tech Publications, Switzerland.


Zhang X.,Zhejiang University of Technology | Hu S.,Zhejiang University of Technology | Tong S.,Zhejiang University of Technology | Cheng Y.,Zhejiang University of Technology | And 3 more authors.
Applied Mechanics and Materials | Year: 2012

TiO 2/CNTs nanocomposites with different Ti/C molar ratios were prepared by a solhydrolysis 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 TiO 2/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. © (2012) Trans Tech Publications, Switzerland.


Li G.,Zhejiang University of Technology | Li G.,State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology | Sun H.,Zhejiang University of Technology | Yu Y.,Zhejiang University of Technology | Xie W.,Zhejiang University of Technology
Huagong Xuebao/CIESC Journal | Year: 2015

Tungsten trioxide nanorod was prepared by a hydrothermal method using sodium tungstate as tungsten source and sodium chloride as an inducer. The nanorod was coated with carbon by a hydrothermal reaction once again and using glucose as a carbon source. Match-like carbon nanotube was fabricated by reaction under a mixed gas of H2 and CH4 with a volume ratio of H2 to CH4 of 1:4. The crystal phase, morphology, microstructure and chemical elements of the samples were characterized and analyzed by X-ray diffraction, scanning electron microscope, transmission electron microscope and X-ray energy dispersion spectrum. The results showed that the sample was consisted of carbon nanotube and tungsten carbide (WC). The morphology of the carbon nanotube was of match-like with a length between 0.5 μm and 1.0 μm, and a diameter around 100 nm. WC particles laid in the inner space of the carbon nanotube and the inner diameter of the nanotube was depended on the diameter of WC particle. These implied that WC particle took a catalytic role during the growth of the carbon nanotube. © All right reserved.


Li G.,Zhejiang University of Technology | Li G.,State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology | Yang W.,Zhejiang University of Technology | Tong M.,Zhejiang University of Technology | Zheng X.,Zhejiang University of Technology
Huagong Xuebao/CIESC Journal | Year: 2015

Tungsten carbide and montmorillonite (MMT) nanocomposite was prepared through combining an impregnation approach with a reduction-carbonization method using exfoliated MMT as a support. The samples were characterized by X-ray diffraction, scanning electron microscope and transmission electron microscope. The results showed that the structure of exfoliated MMT was lamellar. The thickness of exfoliated MMT layer was between 10 nm and 15 nm. The edge of exfoliated MMT layer rolled and the interplane distance of exfoliated MMT were enlarged. The crystal phase of the sample was composed of monotungsten carbide (WC), bitungsten carbide (W2C) and MMT. The particles of tungsten carbide were distributed on the surface of exfoliated MMT. The electrochemical reduction activity of the nanocomposite for p-nitrophenol (PNP) was tested by cyclic voltammetry (CV) in acidic solution. It was found that WC/MMT nanocomposite was electrocatalytic active to PNP and its electrocatalytic activity was stable. This implied that the exfoliated MMT was one of the excellent composite carriers to improve the electrocatalytic property of WC, which can be used in other catalysts. © All right reserved.


Cheng Y.,Zhejiang University of Technology | Xie W.,Zhejiang University of Technology | Yao G.,Zhejiang University of Technology | Hu S.,Zhejiang University of Technology | And 2 more authors.
Chinese Journal of Chemical Engineering | Year: 2012

Tungsten carbide and zeolite nanocomposite was prepared by combining a mechanochemical approach with a reduction and carbonization approach, using natural zeolite and ammonia metatungstate as precursors. The sample was characterized by X-ray diffraction and scanning electron microscope. The results showed that the crystal phase of the sample is composed of zeolite, monotungsten carbide and bitungsten carbide. The mass percentage and the crystallite diameter of tungsten carbide change along with the reacted time. Its electrocatalytic activity was measured with a microelectrode system with three electrodes. The results show that its electrocatalytic property is related to its crystal phase and the mass percentage of tungsten carbide, and its electrocatalytic activity is connected with the property of electrolyte, in which it is measured. Synergistic effect between tungsten carbide and zeolite is found during electrocatalysis. © 2012 Chemical Industry and Engineering Society of China (CIESC) and Chemical Industry Press (CIP).


Meng Q.-Q.,State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology | Meng Q.-Q.,Institute of Industrial Catalysis | Wang J.-G.,State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology | Wang J.-G.,Institute of Industrial Catalysis | And 6 more authors.
Catalysis Today | Year: 2011

TiO2 nanotube arrays can be synthesized by several experimental procedures. Here we construct the first theoretical model of the array. Based on the density functional theory calculations, the formation energy of the TiO2 nanotube array is nearly the same as that of rutile TiO 2 (1 1 0) surface. Moreover the electronic properties of TiO 2 nanotube arrays have been analyzed. The thermodynamic properties of H2O splitting on the TiO2 nanotube and nanotube arrays have been discussed using the density functional theory calculations and Gibbs free energy diagrams. The overpotential of H2O splitting is 0.51 and 1.0 eV on the outside and inside of nanotube and 1.13 eV on the inside TiO 2 nanotube of an array. © 2010 Elsevier B.V. All rights reserved.

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