Covalent organic framework-based composite photocatalyst for degrading organic pollutants in water and preparation method of photocatalyst

Abstract

The invention provides a covalent organic framework-based composite photocatalyst for degrading organic pollutants in water and a preparation method of the photocatalyst. The method comprises the following steps: performing ice bath on a covalent organic framework crystalline triazine-based organic framework (CTF-1) solution and a 4-aminobenzoic acid solution, performing stirring, performing washing, and performing vacuum drying to prepare a benzoic acid functionalized CTF-1, wherein the benzoic acid functionalized CTF-1 is labeled as CFB; and performing ball milling to compound the CFB with phosphotungstic acid (H3PW12O40) according to different ratios to obtain H3PW12O40 / CFB, that is, the covalent organic framework-based composite photocatalyst used for degrading the organic pollutants in the water. According to the method provided by the invention, the covalent organic framework CTF-1 is subjected to benzoic acid functional modification, and the phosphotungstic acid is immobilized into the CTF-1, so that monodispersion of the phosphotungstic acid at the molecular level is realized, the photocatalytic activity is effectively improved, and the degradation efficiency on the organicmatter is obviously improved; and the photocatalyst has good stability in the water, long service life, a relatively-simple process, raw materials easy to obtain and a low price, and can be used forindustrial application and promotion.

Description

technical field [0001] The invention relates to the field of degradation of organic pollutants in water bodies, in particular to the preparation of photocatalysts, in particular to a covalent organic framework-based composite photocatalyst and a preparation method for degrading organic pollutants in water bodies. Background technique [0002] With the development of modern industry and agriculture, a large number of toxic and harmful organic pollutants enter the water body, which poses a huge threat to the survival and development of human beings. At present, the methods of sewage treatment mainly include biological treatment, chemical oxidation, physical adsorption, photocatalytic oxidation and so on. Among them, the physical adsorption method is a method that uses porous adsorbents to transfer the enrichment of environmental pollutants to the surface of the adsorbent for removal. It has the advantages of low cost, wide application range, simple operation, no secondary poll...

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Problems solved by technology

[0008] According to the above, the phosphotungstic acid carriers in the existing schemes are diversified, and the photocatalytic properties of the composite materials formed by different carriers are quite different. At present, there is no report that the covalent organic framework is used as a carrier of polyacid to form composite materials. The present invention A covalent organic framework-based composite photocatalyst and its preparation method for degrading organic pollutants in water are proposed, and the good light absorption, large specific surface area and good electrical conductivity of covalent organic framework CTF-1 layered materials are fully utilized The oxidation catalysis, photoactivity and electron "storage" characteristics of phosphotungstic acid greatly improve the separation effect and utilization rate of photogenerated electrons and holes, and realize the effective structure and charge between "phosphotungstic acid-CTF-1" Matching, so as to build an efficient and stable photocatalytic degradation system of organic pollutants

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