Synthesis And Photocatalytic Antifouling Performance Of BiOI Based Semiconductor Film Materials

Marine biofouling affects the normal use of marine engineering materials,which is a difficult issue for human exploitation of the oceans.Therefore,the design and development of new,efficient and environmental friendly antifouling materials is of practical significance.Photocatalytic antifouling technology with its own low energy consumption and environmental friendly advantages attracts more and more attention.In order to overcome the low solar energy utilization of the traditional photocatalytic materials?such as TiO₂?and the hardness recovery processes of photocatalytic powder materials.In this thesis,the visible light response BiOI semiconductor material has been studied.BiOI with hierarchical structure has been synthesized by an easy way under the room temperature.On the basis of that,by using in situ growth method,the BiOI nanostructure film has been successfully fabricated on 304 stainless steel?304SS?substrates and by further using ion-exchange method,the construction of BiOI/BiOBr binary composite film materials has been achieved.Specific research contents are as follows:?1?By controlling coprecipitation conditions,the spherical hierarchical Bi OI has been synthesized at room temperature.Under the visible light,the hierarchical structure BiOI demonstrates efficient bactericidal properties.The study of the sterilization mechanism shown that h+ and ·O₂-free radicals which damage the bacterial cell wall and membrane is the basic reasons for the efficient sterilization of BiOI under the visible light irradiation.?2?The BiOI nanostructure film has been successfully fabricated on 304 SS substrates using in situ growth method for the first time.The best physical stability and photochemical properties of BiOI nanostructure film has been prepared by hydrothermal reaction under 140 ?,PVP 0.10 g for 4 hours.The hierarchical nanostructure BiOI film covered the metal surface and its photocatalytic activity does not declined significantly compared to the BiOI powder materials.Therefore it possesses a good photocatalytic disinfection activity for both marine fouling bacteria and algae.?3?BiOI/BiOBr binary composite thin film materials have been successfully fabricated on 304 SS surface by the ion-exchange method using TBAB.Compared with the BiOI nanostructure film,the photocatalytic activity of the BiOI/BiOBr binary composite film is strengthen for the p-n heterojunction accelerating the separation of the photo-induced electron-hole pairs.Moreover,the bactericidal mechanism of this binary composite film has also been further enriched by its photocatalytic degradation of bacterial plasmid,the genetic material in the bacterial cells.