Magnetic polypyrrole/titanium dioxide/clay nano-composite photocatalyst and preparation method thereof

Abstract

The invention relates to a photocatalyst, in particular to a magnetic polypyrrole / titanium dioxide / clay nano-composite photocatalyst and a preparation method thereof. In the method, a nano-titanium dioxide / clay composite material is prepared by taking clay as a matrix by an in-situ synthesis method; meanwhile, hydrochloric acid generated through the hydrolysis of titanium tetrachloride is used for synthesizing conductive polypyrrole, and an oxidant for synthesizing the conductive polypyrrole forms a magnetic carrier, so that a high-activity recyclable nano-composite photocatalyst is prepared.

Description

technical field [0001] The invention relates to a photocatalyst, in particular to a magnetic polypyrrole / titanium dioxide / clay nanocomposite photocatalyst and a preparation method thereof. Background technique [0002] With the development of industry and the intensification of environmental problems, more and more attention has been paid to the research on organic wastewater treatment. Traditional organic wastewater treatment methods mainly include physical adsorption method, biological method, chemical oxidation method, etc., which have insufficient treatment and cause secondary pollution. Pollution and other issues, photocatalytic degradation method is a new type of organic wastewater treatment method, using semiconductor materials as photocatalysts can deeply degrade organic pollutants in water into carbon dioxide, water and other inorganic substances, common semiconductor material photocatalysts include TiO 2 , SnS, ZnO, CdS, CdSe, etc., in which nano-titanium dioxide (...

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Problems solved by technology

[0002]With the development of industry and the intensification of environmental problems, more and more attention has been paid to the treatment of organic wastewater. Traditional organic wastewater treatment methods mainly include physical adsorption, biological photocatalytic degradation method is a new type of organic wastewater treatment method, using semiconductor materials as photocatalysts to deeply degrade organic pollutants in water into carbon dioxide, Water and other inorganic substances, common photocatalysts for semiconductor materials include TiO2, SnS, ZnO, CdS, CdSe, etc. Stable performance and high catalytic activity are the preferred photocatalyst materials. However, nano-titanium dioxide photocatalysts also have shortcomings in water treatment applications: (1) The recovery of nano-titanium dioxide

Due to the small particle size and easy loss of nano-titanium dioxide, it is extremely difficult to separate and recover nano-titanium dioxide particles from water after the reaction

(2) The problem of photocatalytic activity. Titanium dioxide is stimulated by photons to transition from the valence band to the conduction band to form electron-hole pairs, thereby generating a large number of hydroxyl radicals to degrade organic pollutants. However, due to the lack of electron acceptors, the electron-hole pairs Easy to recombine, resulting in a reduction in the number of hydroxyl radicals and a reduction in photocatalytic activity

The method uses ethyl orthosilicate, absolute ethanol, tetrabutyl titanate and ferric oxide as raw materials, which increases the cost and limits the range of product use; Chinese patent CN1724164A discloses the preparation of a magnetically separable composite photocatalyst The method first synthesizes magnetic carrier nickel ferrite particles, then coats nickel ferrite nanoparticles with silicon dioxide by liquid phase deposition, and finally loads titanium dioxide nanoparticles on the nickel ferrite particles coated with silicon dioxide. A composite photocatalyst that can be magnetically separated has been prepared. The preparation process of this method is complicated, the product yield is low, and no measures are taken to suppress the recombination of electron-hole pairs; Chinese patent CN101362087A discloses a preparation method of a noble metal modified titanium dioxide photocatalyst. Precious metals such as Ag, Au, Pt, and Pd are deposited on nano-titanium dioxide, which promotes the separation of photogenerated electron-hole pairs and improves the activity of titanium dioxide photocatalysts, but the precious metals such as Ag, Au, Pt, and Pd used in this method are expensive. , restricting its promotion and application

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