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
Bulk polymerization is one of the most commonly used techniques in polymer preparing due to its relatively simple process,low cost and easier aftertreatment of the product[1-5].Bulk polymerization has attracted much a...Bulk polymerization is one of the most commonly used techniques in polymer preparing due to its relatively simple process,low cost and easier aftertreatment of the product[1-5].Bulk polymerization has attracted much attention in both academic researches and industrial productions of commodity polymers,such as poly(methyl methacrylate)(PMMA)[6]and polystyrene(PS)[7].During the process of bulk polymerization,an autoacceleration phenomenon,which is also referred to as the gel or Trommsdorff effect,is often observed[8].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 Natural Science Foundation of Zhejiang Province,China(Nos.2012C32007,LQ20B020002).
文摘Bulk polymerization is one of the most commonly used techniques in polymer preparing due to its relatively simple process,low cost and easier aftertreatment of the product[1-5].Bulk polymerization has attracted much attention in both academic researches and industrial productions of commodity polymers,such as poly(methyl methacrylate)(PMMA)[6]and polystyrene(PS)[7].During the process of bulk polymerization,an autoacceleration phenomenon,which is also referred to as the gel or Trommsdorff effect,is often observed[8].
