N-TiO2/BaAl2O4:Eu<2+>,Dy<3+> composite photocatalyst, preparation method and application thereof

Abstract

The invention discloses a N-TiO2 / BaAl2O4:Eu<2+>,Dy<3+> composite photocatalyst, and belongs to the category of catalyst. The N-TiO2 / BaAl2O4:Eu<2+>,Dy<3+> composite photocatalyst can be applicable for acatalytic conversions of vapor organic contaminants. Compared to pure TiO2, the N-TiO2 / BaAl2O4:Eu<2+>,Dy<3+> composite photocatalys has substantially improved catalytic activity and has response ability to visible light. Because partial photo generated holes generated from the BaAl2O4:Eu<2+>,Dy<3+> migrate to a valence band of the N-TiO2 under illumination, photogenerated electrons of a conduction band of the N-TiO2 are captured through trapping level formed through a lattice defect of the BaAl2O4:Eu<2+>,Dy<3+>, such that the photogenerated electrons of the N-TiO2 is separated from the photo generated holes of the N-TiO2, recombination rate is reduced, and the catalytic activity is raised. In addition, in the N-TiO2, because a localized state of an N2p orbital is formed above the valence band of the TiO2, width of a forbidden band of the TiO2 is narrow, a absorption edge of the TiO2 has a redshift, and a spectral response range of the TiO2 is developed to the visible region.

Description

Technical field: [0001] The invention belongs to the category of catalysts, in particular to a composite photocatalyst N-TiO 2 / BaAl 2 o 4 :Eu 2+ , Dy 3+ preparation and its application in photocatalysis. Background technique: [0002] With the increasingly prominent environmental pollution, the air quality problem has attracted more and more people's attention. The 1990 U.S. Clean Air Act amendment listed 189 toxic and harmful gases, most of which are volatile organic pollutants in the air. In the past few decades, people have focused their attention on the air pollution and control of the external environment. In the past ten years, people have only realized the hygienic significance of indoor air. Europe, North America, Japan and other countries have started research work on indoor environmental quality since the 1980s, and my country has also formulated a series of "Indoor Air Quality Standards" at the end of the last century, as a basis for evaluating indoor air q...

AI Technical Summary

Problems solved by technology

However, TiO 2 The application of photocatalysts is still limited by two aspects: First, due to the 2 The bandgap of TiO is wide, about 3.2eV, and can only be excited by ultraviolet light with a wavelength less than 389nm, thus broadening the TiO 2 The spectral response range of photocatalysts, so that they still have catalytic activity under visible light irradiation, has become an important issue that needs to be solved urgently; two, TiO 2 After being excited by light, the lifespan of photogenerated electrons and photogenerated holes is very short. Once the two recombine, they lose their catalytic activity.