Aluminum-silicon dioxide-titanium dioxide composite photocatalyst and preparation method thereof

Abstract

The invention discloses an aluminum-silicon dioxide-titanium dioxide composite photocatalyst and a preparation method thereof, and belongs to the technical field of photocatalysis. In the photocatalyst, the surfaces of Al nanoparticles are coated with a SiO2 layer, the particle size of the Al nanoparticles ranges from 50 nm to 100 nm, the thickness of the SiO2 layer ranges from 5 nm to 10 nm, TiO2nanoparticles are distributed on the surface of the SiO2 layer, and the particle size of the TiO2 nanoparticles ranges from 5 nm to 20 nm. The preparation method comprises the following steps: firstly, adding cysteine into an Al nanoparticle turbid liquid, and stirring to obtain a surface-modified Al nanoparticle turbid liquid; secondly, dropwise adding an ethanol solution of tetraethyl orthosilicate into the surface-modified Al nanoparticle turbid liquid, stirring after dropwise adding is finished, and generating a SiO2 layer on the surface of the Al nanoparticle, so as to obtain an Al nanoparticle turbid liquid coated with the SiO2 layer; thirdly, adding glutathione into the Al nanoparticle turbid liquid coated with the SiO2 layer, adding TiO2 nanoparticles after stirring, stirring continuously to obtain Al-SiO2-TiO2 composite photocatalyst turbid liquid, removing supernatant in a centrifugal spin-drying mode, and obtaining the aluminum-silicon dioxide-titanium dioxide composite photocatalyst.

Description

technical field [0001] The invention relates to an aluminum-silicon dioxide-titania composite photocatalyst and a preparation method thereof, belonging to the technical field of photocatalysis. Background technique [0002] With the development of society, people are increasingly relying on various industrial products in their lives, such as plastics, pesticides, dyes, textile printing and dyeing products, etc. However, a large amount of organic waste water is produced in the production process of these industrial products, many of which have high toxicity and are not easy to degrade, seriously polluting water bodies. These organic substances can also cause environmental damage. For example, after these organic substances enter the water body, they can be decomposed by aerobic microorganisms, which will greatly reduce the dissolved oxygen in the water body, and even cause anoxic state, endanger aquatic organisms, and kill a large number of fish. Therefore, measures need to ...

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Problems solved by technology

However, on the one hand, the price of the noble metal is very high, and the cost of the catalyst is bound to be greatly increased; on the other hand, the surface plasmon resonance wavelength range of gold and silver nanoparticles is usually in the visible light band, although Bi 2 Te 3 、 Bi 2 Se 3 The wavelength range of the surface plasmon resonance is in the visible and near-infrared bands. However, the existing wide-bandgap semiconductor material TiO 2 But it is the most commercialized photocatalytic semiconductor material, unfortunately TiO 2 It can only respond to ultraviolet light, if you want to accommodate TiO 2 This characteristic requires the regulation of the morphology and size of gold and silver nanoparticles, otherwise it is impossible to combine gold and silver nanoparticles with TiO 2 The composite mode enhances the semiconductor photocatalytic effect; moreover, in the prior art, a kind of gold-silicon dioxide-titania composite photocatalyst has appeared, and its structural characteristic is made of SiO2 2 Layer-encapsulated Au particles attached to 300 nm thick TiO 2 film, such as figure 1 As shown, however, Au particles with TiO 2 The contact surface of the film is too small, the surface plasmon resonance effect at the interface between the metal particle and the semiconductor material is too weak, and the photocatalytic efficiency is low

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