Density functional theory （DFT） plays a significant role in the development of visible light responsive photocatalysts. Based on the first-principles plane-wave ultrasoft pseudopotential （USPP） method, the crystal...Density functional theory （DFT） plays a significant role in the development of visible light responsive photocatalysts. Based on the first-principles plane-wave ultrasoft pseudopotential （USPP） method, the crystal structures of α,β,γ, and 5-Bi2O3 were optimally calculated for the total density of states （TDOS） and the partial density of states （PDOS） of Bi, O atoms. The calculation for Ti（IV） doped Bi2O3 supercell was carried out. The effects of Ti（IV）-doping on the electron structures and light absorption properties of various Bi2O3 were analyzed. The results showed that Ti 3d orbital appeared in the forbidden band of Bi2O3 and hybridized with O 2p, Bi 6p orbitals. The narrowed band gap （Eg） and red-shift of light absorption edge are responsible for the enhanced photoeatalytic activity of Bi2O3. The Ⅱ-Bi2O3 and Ti-doped β-Bi2O3 were prepared by a hydrotherrnal synthesis method. The improvement of the photoeatalytic activity of Bi2O3 has also been verified by the characteristics of the UV-vis diffuse reflection spectrum and the experimental evaluation of the photocatalytic degradation of crystal violet in aqueous solution.展开更多
To well describe the Ti（IV）-catalyzed H2O2/O3 reaction in aqueous solution, a kinetic model was established based on its mechanism. This model was then validated by the experiments of acetic acid degradation in aque...To well describe the Ti（IV）-catalyzed H2O2/O3 reaction in aqueous solution, a kinetic model was established based on its mechanism. This model was then validated by the experiments of acetic acid degradation in aqueous solution. It was found that the correlation coefficient of fittings was higher than 0.970. Three key operating factors affecting organic degradation in the Ti（IV）-catalyzed H2O2/O3 process were studied, including Ti（IV） concentration, dissolved ozone concentration and initial H2O2 concentration. Furthermore, some experiments were conducted to determine the rate constant for dissolved ozone decomposition initiated by Ti2O52＋. The rate constant measured is almost in accord with the data analyzed by this kinetic model. The goodness of fittings demonstrated that this model could well describe the kinetics of the Ti（IV）-catalyzed H2O2/O3 reaction mathematically and chemically. Therefore, this kinetic model can provide some useful information to optimize the parameters in ozonation of water containing certain pollutants.展开更多
The nucleophilic addition of Ti(IV) enolate derived from methyl aryl ketones to α, β–unsaturated compounds was found to be highly selective to give 1, 2 addition products.
In order to combine the properties of inorganic ion exchanger and conducting organic polymer,a new class of organic-inorganic composite cation exchanger PANI-Ti(IV)phosphosulphosalicylate(PTPSS)was synthesized by inte...In order to combine the properties of inorganic ion exchanger and conducting organic polymer,a new class of organic-inorganic composite cation exchanger PANI-Ti(IV)phosphosulphosalicylate(PTPSS)was synthesized by intercalating polyaniline(PANI)into Ti(IV)phosphosulphosalicylate(Ti(IV)PSS)using sol-gel chemical route with enhanced properties.PTPSS has been characterized by using Fourier Transform Infrared Spectroscopy(FT-IR),X-ray diffraction(XRD),Scanning Electron Microscopy(SEM),Energy dispersive X-ray(EDAX),thermo gravimetric analysis(TGA-DTG),and Transmission Electron Microscopy(TEM).Ac electrical conductivity studies were also performed.This material possessed electrical conductivity of 10^(−3)-10^(−6)Scm^(−1) which falls in the semiconducting range.The frequency(2×10^(5)-1×10^(6)Hz)dependent Ac conductivity at room temperature suggests the evidence for the transport mechanism for the conductivity in PTPSS.The structure of the composite cation exchanger extremely supports its conducting behavior.展开更多
基金supported by the National High Technology Research and Development Program (863 program, 2006AA06Z323)National Key Technology R&D Program (2008BAC32B06-3) of Chinaspecial fund of State Key Laboratory of Water Environment Simulation (08ESPCT-Z)
文摘Density functional theory （DFT） plays a significant role in the development of visible light responsive photocatalysts. Based on the first-principles plane-wave ultrasoft pseudopotential （USPP） method, the crystal structures of α,β,γ, and 5-Bi2O3 were optimally calculated for the total density of states （TDOS） and the partial density of states （PDOS） of Bi, O atoms. The calculation for Ti（IV） doped Bi2O3 supercell was carried out. The effects of Ti（IV）-doping on the electron structures and light absorption properties of various Bi2O3 were analyzed. The results showed that Ti 3d orbital appeared in the forbidden band of Bi2O3 and hybridized with O 2p, Bi 6p orbitals. The narrowed band gap （Eg） and red-shift of light absorption edge are responsible for the enhanced photoeatalytic activity of Bi2O3. The Ⅱ-Bi2O3 and Ti-doped β-Bi2O3 were prepared by a hydrotherrnal synthesis method. The improvement of the photoeatalytic activity of Bi2O3 has also been verified by the characteristics of the UV-vis diffuse reflection spectrum and the experimental evaluation of the photocatalytic degradation of crystal violet in aqueous solution.
基金supported by the National Natural Science Foundation of China (No. 50578146, 20876151,21176225)the Natural Science Foundation of Zhejiang Province, China (No. Y5080178)
文摘To well describe the Ti（IV）-catalyzed H2O2/O3 reaction in aqueous solution, a kinetic model was established based on its mechanism. This model was then validated by the experiments of acetic acid degradation in aqueous solution. It was found that the correlation coefficient of fittings was higher than 0.970. Three key operating factors affecting organic degradation in the Ti（IV）-catalyzed H2O2/O3 process were studied, including Ti（IV） concentration, dissolved ozone concentration and initial H2O2 concentration. Furthermore, some experiments were conducted to determine the rate constant for dissolved ozone decomposition initiated by Ti2O52＋. The rate constant measured is almost in accord with the data analyzed by this kinetic model. The goodness of fittings demonstrated that this model could well describe the kinetics of the Ti（IV）-catalyzed H2O2/O3 reaction mathematically and chemically. Therefore, this kinetic model can provide some useful information to optimize the parameters in ozonation of water containing certain pollutants.
文摘The nucleophilic addition of Ti(IV) enolate derived from methyl aryl ketones to α, β–unsaturated compounds was found to be highly selective to give 1, 2 addition products.
文摘In order to combine the properties of inorganic ion exchanger and conducting organic polymer,a new class of organic-inorganic composite cation exchanger PANI-Ti(IV)phosphosulphosalicylate(PTPSS)was synthesized by intercalating polyaniline(PANI)into Ti(IV)phosphosulphosalicylate(Ti(IV)PSS)using sol-gel chemical route with enhanced properties.PTPSS has been characterized by using Fourier Transform Infrared Spectroscopy(FT-IR),X-ray diffraction(XRD),Scanning Electron Microscopy(SEM),Energy dispersive X-ray(EDAX),thermo gravimetric analysis(TGA-DTG),and Transmission Electron Microscopy(TEM).Ac electrical conductivity studies were also performed.This material possessed electrical conductivity of 10^(−3)-10^(−6)Scm^(−1) which falls in the semiconducting range.The frequency(2×10^(5)-1×10^(6)Hz)dependent Ac conductivity at room temperature suggests the evidence for the transport mechanism for the conductivity in PTPSS.The structure of the composite cation exchanger extremely supports its conducting behavior.
