Infrared light excited bismuth tungstate photocatalyst and preparation method thereof

Abstract

The invention discloses an infrared light excited bismuth tungstate photocatalyst and a preparation method thereof. The preparation method comprises the following steps: dissolving rare earth oxides into nitric acid at a high temperature, repeatedly evaporating the nitric acid, dissolving the solids again to obtain a rare earth nitrate solution; dissolving bismuth nitrate into diluted nitric acid, adding the rare earth nitrate solution, primarily stirring to evenly mix the solutions, adding a certain amount of EDTA ammonia solution, fully stirring to form a transparent Bi-EDTA mixed solution; slowly adding the EDTA ammonia solution into an ammonium tungstate solution, fully stirring until a transparent solution is formed; mixing the Bi-EDTA mixed solution and the transparent solution, stirring the mixed solution for a while under heating at a constant temperature, adjusting the pH value of the solution by ammonia liquor and nitric acid, heating the mixed solution in a water bath with a temperature of 80 DEG C, stirring the mixed solution under heating until the mixed solution becomes transparent to obtain bismuth tungstate precursor sol, drying and burning the bismuth tungstate precursor sol to remove the organic substances in the bismuth tungstate precursor sol, and finally burning the bismuth tungstate precursor sol to form bismuth tungstate nano powder. The provided preparation method has the advantages of milder reaction conditions and higher safety.

Description

technical field [0001] The invention belongs to the technical field of photocatalysis, and in particular relates to a bismuth tungstate photocatalyst excited by infrared light and a preparation method thereof. Background technique [0002] Photocatalysis can effectively convert light energy into chemical energy. At present, more researches are on TiO with high catalytic activity and good stability. 2 , but its wide forbidden band (3.2eV) can only absorb ultraviolet light of λ≤387nm, which restricts the large-scale application of this technology. Bismuth tungstate (Bi 2 WO 6 ) as a new type of visible light-responsive photocatalytic material, which has a narrow band gap (2.7eV), has good photocatalytic activity under both ultraviolet and visible light, and can effectively degrade organic pollutants in wastewater. This scheme introduces rare earth Ions, using the up-conversion properties of rare earth ions to realize infrared photocatalysis. [0003] Since 1999, Kudo et al...

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Problems solved by technology

[0003] Since 1999, Kudo et al first reported bismuth tungstate (Bi 2 WO 6 ) has photocatalytic activity under visible light radiation with a wavelength greater than 420nm, Bi 2 WO 6 The synthesis of bismuth bismuth tungstate often adopts the method of solid phase sintering: the oxide or its salt containing Bi element and W element is mechanically mixed and directly sintered at a high temperature of about 1000 degrees; the bismuth tungstate photocatalytic material is prepared by hydrothermal method, The subsequent spin coating and filling process cannot be carried out by using a hydrothermal kettle; the preparation of bismuth tungstate photocatalytic materials by the sol-gel method has milder reaction conditions and higher safety, but the chelating agent used in the experiment There are many types and dosages, and lead to poor fluidity when the sol concentration is high, and poor compatibility with subsequent spin coating, filling and other processes

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