A cu-doped tio2-coupled semiconductor photocatalyst, preparation method and application

Abstract

The invention discloses a Cu-doped TiO2 coupled semiconductor photocatalyst Cu-TiO2 / ZnBi12O20 belonging to the category of catalysts, which is used for catalytic conversion of gas phase organic pollutants. Compared with pure TiO2, the catalyst not only extends the spectral response range to the visible light region, but also greatly improves the quantum efficiency and catalytic activity. This is because ZnBi12O20 has a narrow band gap and is active in visible light; and after TiO2 is doped with Cu to form Cu-TiO2, it not only narrows the band gap, makes it have visible light responsiveness, but also modulates the energy level position, coupling with ZnBi12O20 , the energy levels of the two are matched, so that the photogenerated carriers are effectively separated, and the quantum efficiency and catalytic activity are greatly improved.

Description

Technical field: [0001] The invention belongs to the category of catalysts, in particular to a Cu-doped TiO 2 Preparation of coupled semiconductor photocatalyst and its application in photocatalysis. Background technique: [0002] Using TiO 2 Semiconductor photocatalytic degradation of organic pollutants has become a research hotspot in the field of environmental catalysis, but the practical application of this technology is still limited by TiO 2 The recombination rate of photogenerated electrons and holes is high, the quantum efficiency is low; the band gap is wide (anatase TiO 2 About 3.2eV), the need for ultraviolet excitation with a wavelength below 387nm, and the limitations of factors such as low utilization of the solar spectrum. [0003] TiO 2 Various modification techniques such as ion doping, noble metal deposition, semiconductor coupling, surface sensitization, etc., among which the appropriate semiconductor and TiO 2 Coupling is a better method that can not...

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Problems solved by technology

[0004] However, the number of such photocatalysts is still small due to the choice of TiO 2 The coupled semiconductor needs to meet two basic conditions: 1, the band gap is narrow, and it has visible light activity; 2, the energy band level and TiO 2 matches the

Such as WO 3 / TiO 2 System (Song KY, Park M K, Kwon Y T "Preparation of Transparent Particulate MoO 3 / TiO 2 and WO 3 / TiO 2 Films and Their Photocatalytic Properties" "Chem. Mater" 2001, 13: 2349~2355), ZnO / TiO 2 System and SnO 2 / TiO 2 system (Liu Chunyan "Nano Photocatalysis and Photocatalytic Environmental Purification Materials" Chemical Industry Press 2008. First Edition 68~69), although WO 3 / TiO 2 , ZnO / TiO 2 and SnO 2 / TiO 2 The catalytic activity of coupled photocatalysts is greatly improved (such as WO 3 / TiO 2 The activity of pure TiO 2 nearly 3 times that of ), but due to WO 3 , ZnO and SnO 2 The bandgap is wide (WO 3 and the bandgap of ZnO is 3.2eV, SnO 2 The band gap is 3.8eV), therefore, these coupled photocatalysts have no visible light activity; and any narrow band gap semiconductor with visible light responsiveness and TiO 2 coupling, if its band energy level is the same as that of TiO 2 As a result, the photogenerated carriers cannot be effectively separated, and as a result, the spectral response range may be extended to the visible light region, but the catalytic activity cannot be greatly improved.

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