Preparation And Photocatalytic Activity Of Organic Magnetic Nano-TiO₂-SiO₂ Photocatalyst

With the continuous development of science and technology,the environmental pollution caused by industrial production is becoming more and more serious,which brings huge problems to the environment in which we live.Controlling environmental pollution is imminent.In the process of industrial production,many waste liquids are discharged to cause pollution of the water environment,including organic and inorganic wastewater.Many organic substances are difficult to be biodegraded,which may be decomposed into toxic metabolites or carcinogens under the action of microorganisms,so that causing harm to human health.At present,photocatalytic technology has been widely used in sewage treatment.Photocatalysts such as TiO2,ZnO,CdS,ZrO2,etc.can convert toxic and harmful pollutants into harmless substances.Among many photocatalysts,TiO2 is an inorganic functional material with relatively stable chemical properties,photochemical resistance and acid and alkali corrosion resistance,which has low preparation cost,high catalytic activity,strong oxidizing ability,no secondary pollution and other advantages.However,the nano TiO2 particles are small and have a high surface energy,so that the particles are easily agglomerated and not easily dispersed.At the same time,the TiO2 photocatalyst is difficult to separate in use,which is not conducive to the circulation and reuse of the catalyst.In this paper,ferrocene organic magnetic monomer was used as the magnetic source,and tetrabutyl titanate was used as the titanium source.Hydrothermal method was used to make Ti02 and magnetic component together.By controlling the ratio of raw materials,reaction time and reaction temperature during the reaction,using XRD,SEM and VSM to characterize the samples,and studing the photocatalytic degradation activity of organic magnetic nano-TiO2 on methylene blue.The results showed that the ratio of reaction raw materials,reaction time and reaction temperature had certain influence on the photocatalytic effect of organic magnetic nano-TiO2.With the increase of temperature,the photocatalytic activity of organic magnetic nano-TiO2 was gradually increased.As the reaction time increased,the photocatalytic effect first rised and then decreased.At the same time,the prepared organic magnetic nano TiO2 photocatalyst had normal temperature ferromagnetism,which can be recycled smoothly by the external magnetic field.In order to improve the photocatalytic performance,the organic magnetic material FOM was used as the magnetic core,and the tetrabutyl titanate was the source of titanium,and the tetraethyl orthosilicate was the source of silicon.The hydrothermal synthesis of organic magnetic silicon-titanium material was by the method of coating and common synthesis.By controlling the ratio of raw materials,reaction time and reaction temperature during the reaction,the samples were characterized by XRD,SEM and VSM,and the photocatalytic degradation activity of organic magnetic silicon-titanium material synthesized by two different synthetic methods for methylene blue was studied.When the organic magnetic SiO2 composite material was coated by the coating method,when the organic magnetic SiO2:tetrabutyl titanate was 1:3 and the synthesis temperature was 130? for 4 h,the photocatalytic performance of the composite was the best,and the degradation of the methylene blue solution was carried out.The rate is 88.8%.At the same time,in the process of four recycling,the degradation rate is above 70%.When synthesized by the common synthesis method,the ratio of ethyl orthosilicate to tetrabutyl titanate is 1:2 at 130?,and the photocatalytic effect of the synthesized organic magnetic silicon-titanium composite is the best when reacted for 4 h.The degradation rate of methylene blue solution was 94.2%.At the same time,in the process of four recycling,the degradation rate is above 85%.The use of organic magnetic materials and SiO2 to modify TiO2 together reduced the agglomeration of nano-TiO2 particles,which not only increased the photocatalytic effect,but also had good norma temperature ferromagnetism.And the composite catalyst can be separated smoothly under the action of the external magnetic field,so that achieving catalyst recycling and reducing pollution.