Silver-modified bismuth tungstate composite photocatalyst, its preparation method and application thereof

Abstract

The invention discloses a silver-modified bismuth tungstate composite photocatalyst, its preparation method and an application thereof. Bismuth tungstate in the catalyst is granules with the particle size being 0.5-3 microns and the catalyst is composed of bismuth tungstate pieces, the length of which is 30-100 nm and the thickness of which is 5-10 nm. Silver granules with the particle size being 5-40 nm are modified on the bismuth tungstate pieces. The specific surface area of the catalyst is 10-30 m<2> / g. The preparation method comprises the following steps of: respectively adding bismuth nitrate into a nitric acid solution with stirring to obtain a bismuth nitrate solution and adding polyvinylpyrrolidone into a sodium tungstate solution with stirring to obtain a mixed solution, adding the bismuth nitrate solution into the mixed solution, placing in an enclosed state, keeping warm at 160-180 DEG C for 20-24 h, centrifuging, washing, drying to obtain a bismuth tungstate powder, adding the bismuth tungstate powder into a silver nitrate solution, stirring, drying, grinding into a powder, and roasting the powder to prepare the target product. The product can be used in water polluted by organic matters or heavy metal ions to perform visible light photodegradation.

Description

technical field [0001] The invention relates to a photocatalyst and its preparation method and application, in particular to a silver-modified bismuth tungstate composite photocatalyst and its preparation method and application. Background technique [0002] The global environmental pollution problem restricts the progress of human civilization, and the elimination of environmental organic pollutants needs to consume a lot of energy, which poses a severe challenge to the increasingly depleted energy. The use of photocatalytic technology to degrade environmental pollutants has the advantages of low energy consumption, mild reaction conditions, easy operation, and can reduce secondary pollution, so it has attracted more and more attention. In recent years, a large number of studies have shown that almost all organic pollutants can be effectively degraded, decolorized, detoxified, and mineralized into small inorganic molecules by semiconductor photocatalysis, thereby eliminatin...

AI Technical Summary

Problems solved by technology

However, both the catalyst and its preparation method have shortcomings. First, the final product is composed of particles with a particle size of 10-20 nm, and the particle size of the silver particles loaded on it is 0.236 nm. Although the final product with small particle size has a larger specific surface area, it is very easy to agglomerate, and it is not easy to recycle it when it is recycled, which greatly restricts the effectiveness of being used as a photocatalyst; secondly, the addition of raw materials in the preparation method The sequence is not correct and no surfactant is used, making it difficult for the final product to have a morphology that is prone to photocatalytic degradation

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