Visible-Light Excitated Photocatalytic Activity of Rare Earth Metal-Ion-Doped Titania
来源期刊:JOURNAL OF RARE EARTHS2002年第6期
论文作者:李萍 袁春伟 谢一兵
Key words:rare earths; amorphous phase; polycrystalline phase; photocatalysis process; self-photo-sensitization photolysis; interband trap site; electron scavenger;
Abstract: The rare earth ion Ce4+ doped TiO2 was prepared by sol-gel method. The average particle sizes are about 10 nm for sol phase and 55 nm for polycrystalline phase. The photocatalytic activities to degrade Reactive Brilliant Red Dye X-3B were investigated. The result reveals that the spectrum response of Ce4+-TiO2 has extended to visible region from the UV region(λ<387 nm) of pure TiO2. Amorphous phase Ce4+-TiO2 sol with an electron scavenger (1.0% atom fraction Ce4+ ion doping amount) shows the capability of the photocatalytic degradation of the dye X-3B as well as the nanocrystallite Ce4+-TiO2 with an interband trap site. Despite of the difference in the morphology of Ce4+-TiO2 photocatalyst, there is no apparent difference in respect of the decoloring effects. Whereas, polycrystalline phase Ce4+-TiO2 exhibits strong photomineralization power in comparison with the amorphous phase. The photocatalytic oxidation mechanisms of the dye molecule mainly involved in the self-photo-sensitization photolysis process by the first excited singlet oxygen (1O2) and photocatalysis process by hydroxyl radicals(*OH) under visible light irradiation.
李萍1,袁春伟1,谢一兵1
(1.National Laboratory of Molecular & Biomolecular Electronics, Southeast University, Nanjing, 210096, China)
Abstract:The rare earth ion Ce4+ doped TiO2 was prepared by sol-gel method. The average particle sizes are about 10 nm for sol phase and 55 nm for polycrystalline phase. The photocatalytic activities to degrade Reactive Brilliant Red Dye X-3B were investigated. The result reveals that the spectrum response of Ce4+-TiO2 has extended to visible region from the UV region(λ<387 nm) of pure TiO2. Amorphous phase Ce4+-TiO2 sol with an electron scavenger (1.0% atom fraction Ce4+ ion doping amount) shows the capability of the photocatalytic degradation of the dye X-3B as well as the nanocrystallite Ce4+-TiO2 with an interband trap site. Despite of the difference in the morphology of Ce4+-TiO2 photocatalyst, there is no apparent difference in respect of the decoloring effects. Whereas, polycrystalline phase Ce4+-TiO2 exhibits strong photomineralization power in comparison with the amorphous phase. The photocatalytic oxidation mechanisms of the dye molecule mainly involved in the self-photo-sensitization photolysis process by the first excited singlet oxygen (1O2) and photocatalysis process by hydroxyl radicals(*OH) under visible light irradiation.
Key words:rare earths; amorphous phase; polycrystalline phase; photocatalysis process; self-photo-sensitization photolysis; interband trap site; electron scavenger;
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