Study On The Preparation,Modification And Photocatalytic Properties Of BiOI Materials

In recent years,the development of textile printing and dyeing industry is very rapid.Water pollution caused by printing and dyeing wastewater has seriously affected people’s quality of life and ecological environment.How to efficiently degrade dye wastewater has become a major difficulty in the research field.Photocatalytic technology can degrade organic dyes in water under light,and is one of the green technologies with broad application prospects.However,the traditional photocatalysts have many defects,which limits their application.In this paper,BiOI nanomaterials are prepared,and RhB is used to simulate the photocatalytic degradation of dye wastewater.Aiming at the shortcomings of the high recombination rate of photogenerated electrons and holes,it is modified by two methods to improve photocatalysis performance.Finally,in view of the defects of the powdered photocatalyst being easy to agglomerate and not easy to recycle,the powdered photocatalyst is supported on the fiber membrane by the electrostatic spinning technology to improve the reusable rate.In this paper,a hydrothermal synthesis method is used to prepare BiOI nanomaterials using ethylene glycol as a solvent.The effects of reaction temperature and reaction time on the morphology and structure of BiOI are studied.140℃ and 12h are selected as the best reaction parameters.At this time,the degradation rate is 81.7%.The following two methods are used to modify BiOI.First,add nano-TiO2 to the BiOI reaction solution to prepare n-TiO2/p-BiOI composite material,and explore the effect of the addition of TiO2 on the morphology and structure of the n-TiO2/p-BiOI nanomaterial.The results show that the photocatalytic effect of TiO2 is the best when the amount of TiO2 is 7%,and the degradation rate is 85.8%.Secondly,the Ag/AgI/BiOI ternary composite photocatalyst is prepared by ions-exchange combined with photoreduction.When the addition amount of Ag/AgI is 10%,the photocatalytic effect reach the best and the degradation rate is 98%,which significantly improve the degradation rate.We use the electrospinning technology to prepare PAN nanofiber membrane as the supporting carrier of powder photocatalyst,and prepare BiOI/PAN,n-TiO2/p-BiOI/PAN,Ag/AgI/BiOI/PAN nanofiber film,respectively.The experimental results show that the photocatalytic effect of the fiber membrane loaded with nanoparticles decreases slightly but still has good photocatalytic performance.After three repeate experiments,the degradation rate decrease by only about 2%,indicating that the binding of nanoparticles to PAN fiber membrane is very stable.It not only improves the photocatalytic performance of BiOI nanomaterials,but also improves their dispersibility and recyclability.