Study On Preparation And Properties Of Magnetic Diatomite Composites

China is rich in diatomite deposits.Diatomite is characterized by its unique microporous structure,large specific surface area,strong adsorption and high temperature resistance.It is widely used in air purification,sewage treatment and catalyst research and development.In order to solve the deficiency in the development of diatomite based catalytic materials,semiconductor photocatalysts with visible light response were explored.It is a trend to improve the performance of catalysts.MgFe₂O₄ and ZnFe₂O₄ are derived from initial ferrite Fe₃O₄,and have unique magnetic,electrical,wave absorbing and photocatalytic properties in spinel ferrite.MgZnFe₂O₄ is a kind of compound ferrite with superparamagnetic.Unlike a single catalytic or wave-absorbing material,this molecular coupling can enhance the performance of a variety of devices,including solar cells and photoluminescent devices.In this paper,MgZnFe₂O₄ was used as the research subject to explore the preparation method of diatomite supported catalyst,adding ferrite to improve the photocatalytic performance of TiO₂,and the wave-absorbing performance of magnetic diatomite based photocatalyst due to the addition of ferrite.The main research work of this paper is as follows:?1?Mg_xZn_1-xFe₂O₄ composite ferrite with different mole ratios and Fe₃O₄ was prepared by hydrothermal method.The structure and properties of the catalyst were characterized by XRD,XPS,SEM and UV-Vis.The results showed that the crystallinity of the sample was good,about 100 nanometers,and it was a cubic spinel structure.The crystallinity of Mg_xZn_1-xFe₂O₄ was high when x was 0.2,0.4 and 0.6.The single-phase MgFe₂O₄ can easily coexist with a small amount of Fe₂O₃.The addition of Zn inhibited hematite phase formation.?2?The catalytic activity of diatomite-based composite in organic dyes was studied.The results show that diatomite disperses ferrite and reduces ferrite aggregation,and its porous surface helps to reduce the density of photocatalytic adsorption and electromagnetic absorption materials.The results show that the Mg-Zn ferrite/diatomite composite combines the photocatalytic and electromagnetic absorption properties of ferrite materials with the adsorption properties of inorganic diatomite.Comprehensive performance is a new direction of application value exploration of composite materials in architectural functional coatings.?3?Experimental studies show that the carrier plays an extremely significant role.TiO₂formed on the surface of diatomite and between the surface of diatomite and ferrite after calcination are both spinel crystalline phases,and the highly dispersed nano TiO₂ crystals show a good photocatalytic promotion.Ferrite and TiO₂ form semiconductor-semiconductor composite photocatalytic material,and the heterojunction can delay the photogenic carrier recombination,so as to improve the catalytic effect.Among them,the results of 0.2MZDT and ZDT were better in the samples forged at 500?,and the degradation rate reached about60-70%after 90min.