Visible light response nano TiO2 and preparation method for self-cleaned ceramic coating film containing same

Abstract

The invention relates to visible light response nano TiO2 and a preparation method for a self-cleaned ceramic coating film containing the same. The method for preparing a visible light response TiO2 self-cleaned ceramic coating film comprises the following steps: with stirring, adding a mixed liquid of a hydrolysable organic silicon monomer, organic titanate and alcohol into a reaction bottle with neutral to weakly-alkaline deionized water to generate white precipitate; adding a complexing agent into the reaction bottle till at least 80% of the white precipitate is dissolved, and leaving to stand to age for 20-24 hours so as to obtain yellow transparent sol; performing heating backflow for 6-10 hours, and adjusting the pH value by using a pH value adjusting agent till the pH value is 6.5-8.0 so as to obtain silicon doped nano TiO2 sol; adding 0.1-1.0wt% of a filming aid into the silicon doped nano TiO2 sol so as to obtain nano TiO2 varnish with visible light response; spraying the nano TiO2 varnish with visible light response to the surface which is sprayed with a ceramic coating in advance, controlling the thickness of the varnish to be 0.1-1 [mu] m, and performing room-temperature drying or heating drying, thereby obtaining the TiO2 self-cleaned ceramic coating film with visible light response.

Description

technical field [0001] The invention belongs to the technical field of self-cleaning coatings. Specifically, the present invention relates to visible light-responsive nano-titanium dioxide (TiO 2 ) and include the visible light responsive nano-TiO 2 Preparation method of self-cleaning ceramic coating film. Background technique [0002] Nano-TiO 2 Under the irradiation of ultraviolet light, photogenerated electron-hole pairs are generated. Photogenerated holes have a very strong oxidation ability and can capture TiO 2 electrons from surface organic pollutants and interact with H adsorbed on the surface 2 O reacts to generate hydroxyl radicals (·OH) with strong oxidative activity, which are used to oxidize and degrade organic pollutants. At the same time, nano-TiO 2 itself can also be adsorbed on TiO 2 The organic pollutants on the surface are directly oxidized and decomposed, and the inorganic substances that are difficult to biodegrade can also be gradually degraded ...

AI Technical Summary

Problems solved by technology

Since this method is simply physical blending, the dopant ions do not enter the nano-TiO 2 crystal lattice, and therefore have low absorption of visible light

In addition, dopant ions will be gradually dissolved and lost by water, making it difficult to maintain long-term photocatalytic effect

[0009] From the above, it can be seen that the preparation of TiO with visible light response 2 The prior art of self-cleaning coating mainly has the following deficiencies: (1) it needs to be carried out under high temperature or high pressure, which requires special high temperature or high pressure resistant equipment, which not only increases the manufacturing cost, but also is not suitable for surfaces that are not resistant to high temperature ; (2) Use inorganic titanium salt as titanium source, resulting in a large amount of waste water; (3) Doped visible light absorption is low and visible light photocatalytic stability is not good, etc.

[0010] Furthermore, prior art visible-light-responsive self-cleaning TiO 2 Poor film transparency

[0011] In addition, the prior art nano-TiO 2 The sol has good matching properties and adhesion on the surface of glass, metal and other materials, but there is matching blooming on the surface of ceramic coatings (ie, TiO 2 The sol is prone to agglomeration, because TiO 2 Uneven particle distribution, different degrees of agglomeration (causing visual blooming) and poor adhesion

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