Preparation And Photocatalytic Properties Of Bismuth Oxyiodide (BiOI)/Bismuth Oxychloride (BiOCl)@Polyacrylonitrile (PAN) Nanofibers

Water pollution is becoming more and more serious,and even threatens the normal life of human beings.The development of visible photocatalytic materials which can degrade organics in water pollution with low cost,high efficiency,deep degradation and no secondary pollution has become the focus of research.In recent years,bismuth halogenate photocatalysts have attracted much attention due to their special layered structure and indirect bandgap semiconductor properties.In particular,BiOI with limited band width in the visible region can absorb as much visible light as possible and improve the utilization rate of natural light.BiOCl and BiOI have similar structure and crystal structure to meet the conditions of heterogeneous junction to improve the performance of photocatalytic semiconductor which can degrade organics in water pollution.However,nano-photocatalyst BiOX has a powder shape on the macro levels,after the photocatalytic reaction,it is suspended in the catalytic solution and is not easily separated in the solution,seriously reducing its practicality.To solve this problem,I decided to load the composite materials onto the nanofibers.Flexible polyacrylonitrile?PAN?nanofibers which are microscopically one-dimensional nanostructures,macroscopically netting structures,large diameter ratios,high specific surface areas,non-reactive reactions,and simple and inexpensive preparation are considered appropriate carriers.In the experiment,BiOCl and BiOI nanosheets were immobilized on electrospun PAN nanofibers by continuous ion-layer adsorption method combined with electrostatic spinning technology,as to obtain BiOI/BiOCl@PAN composite nanofibers with one-dimensional structure.Characterization instruments include scanning electron microscope,thermogravimetric differential thermal analysis?TG-DTA?,N₂ adsorption desorption curve?BET?,X-ray diffraction,uv-visible diffuse reflection,X-ray photoelectron spectroscopy,transmission electron microscope,etc.It was proved that the heterojunction of BiOI/BiOCl@PAN composite nanofibers was successfully constructed.The load of BiOI nanoparticles was regulated by adjusting the number of impregnations of KI and Bi?NO₃?₃ solutions during the adsorption reaction of BiOI/BiOCl@PAN composite nanofibers.Dyes of Rhodamine B and BPA can be commendably degraded by BiOI/BiOCl@PAN composite nanofibers under full-spectrum irradiations.The results of photocatalysis showed that BiOI/BiOCl@PAN composite nanofibers have strong photocatalytic activity,and RHB can be completely decomposed within60 minutes.It also has a good catalytic effect on BPA.In order to explore the main active species in the photocatalytic degradation process,free radical capture experiments were used to prove that holes are mainly involved in the reaction of useful groups.In the cyclic degradation test,BiOI/BiOCl@PAN composite nanofiber photocatalyst showed good reuse performance and stability.This is due to the catalyst's own network mat structure.