Preparation Of PAN Nanofiber Membrane Loaded With TiO₂/CuS And Its Photocatalytic Performance

With the development of economy,the natural environment has been damaged seriously,and our life is faced with many impacts,among which water pollution is a major problem for us to solve.Traditional water pollution treatment methods,such as physical adsorption and biochemical degradation,have disadvantages of high energy consumption or secondary pollution.As an advanced oxidation process,photocatalytic technology becomes a research hot spot for its high efficiency and green characteristics.Titanium dioxide(TiO2)is one of the most widely used semiconductor photocatalytic materials in the field of photocatalysis.Its band gap is about 3.2 eV.which makes it only respond to ultraviolet light in the natural environment.Meanwhile,the powder material is very easy to agglomerate in the process of application,which has negative effects on photocatalytic performance.Copper sulfide(CuS)has advantages of narrow band gap and shows good response to light in visible region,therefore,the methods of forming heterojunction material with TiO2 and loading it on nanofibers can solve the above problems effectively.In this paper.TiO2/CuS nanocomposites were prepared,and Rhodamine B(RhB)aqueous solution was used as target pollutant for the photocatalytic performance study;Then the polyacrylonitrile(PAN)nanofibers with n-butyl titanate(TBOT)was used as the substrate material for the growth of TiO2/CuS nanoparticles.and the flexible PAN@TiO2/CuS nanofiber membrane photocatalytic material was obtained.The main work contents of this dissertation are as follows:(1)In Chapter 2,TiO2/CuS nanocompsite materials with different mole ratios were prepared by one-step hydrothermal method,in which TiO2 was anatase phase and CuS was covellite phase.RhB aqueous solution was used as the target pollutant to evaluate its photocatalytic performance.The results showed that TiO2/CuS nanocomposite shows better photocatalytic performance than individual TiO2 or CuS,which could be attributed to the synergistic effect between TiO2 and CuS in TiO2/CuS nanocomposite,and the sample TiO2/CuS-20%showed the best photocatalytic effect for it had the highest specific surface area.(2)In Chapter 3,the electrospun PAN nanofiber membrane containing TBOT was used as substrate,and amorphous titanium dioxide(α-TiO2)could grow in situ on fibers’surface by impregnation method.PAN@TiO2/CuS nanofiber membrane with photocatalytic property were prepared by subsequent hydrothermal reaction.The uniform arrangement of TiO2/CuS nanoparticles above PAN nanofibers can reduce the agglomeration of nanoparticles and improve the utilization of the photocatalyst to the light source.PAN@TiO2/CuS nanofiber menbrane showed better photocatalytic performance than TiO2/CuS nanocomposites in the photocatalytic degradation of RhB under visible light.Besides that,nanofiber membrane used as substrate can make photocatalyst materials easy to resue,which can effectively avoid the secondary pollution caused by the loss of photocatalyst to the environment.