Preparation Of Bi₂O₃ Composite Photocatalys Modified And Its Application Research

Bi₂O₃ is a kind of important semiconductor materials,plays an important position in the oxide material system,its forbidden band width,refractive index and its excellent properties of dielectric constant and conductivity are making it a popular material,a new generation of semiconductor photocatalyst which has received the widespread attention.In this paper,the research content is as follows:1.)Using Bi?NO₃?₃·5H₂O and NaOH as raw material,compounds Bi₂O₃ catalyst with square crystal phase structure through chemical precipitation method,acid red B dye degraded by photocatalytic experiment processing,determines the optimum photocatalytic performance of the Bi₂O₃ catalyst preparation temperature was 250 ?;tourmaline-Bi₂O₃ composite catalyst was prepared with tourmaline compound;the samples was observed to phase its structure,morphology and the response of the light by using X-ray diffraction?XRD?,scanning electron microscope?SEM?and uv-vis diffuse?DRS?.Results show that,after adding 5% tourmaline,composite catalyst absorbed sideband position from 510 nm red shift to around 575 nm,catalyst for small diameter spheres,the sample is more loose,better dispersion.2).Put tourmaline-Bi₂O₃ composite catalyst in Mn?NO₃?2 solution for dipping,then gained Mn-Bi₂O₃/tourmaline composite catalyst after high temperature calcined,and characterize.Experimental results showed that,the absorption of composite catalyst sideband position from about575 nm,red moved in 612 nm,Mn-Bi₂O₃/tourmaline composite catalyst improve the intensity of light absorption and light response range,and photocatalytic performance experiment proved good photocatalytic performance of the composite photocatalyst.Experiments show that,reaction at 60 min,Mn-Bi₂O₃/tourmaline composite catalyst for methylene blue dye solution of chroma removal rate can reach 73.64%.3.)Orthogonal test confirm the influence of methylene blue dye solution treated by the composite catalyst on the experimental factors:The dye concentration had the greatest influence on the catalytic activityof catalyst,initial pH value,followed by solution and the effect of composite catalyst dosing quantity is minimal.The optimum processing conditions are: dye solution p H was 5,composite catalyst dosage was1.25 g/L,dye solution concentration was 10 mg/L.Reaction under visible light irradiation,after 60 min,Mn-Bi₂O₃/tourmaline composite catalyst for Methylene blue dye solution of chrominance removal rate was95.6%.4.)Research on the reaction kinetics of Methylene blue dye treated by Mn-Bi₂O₃/tourmaline composite catalyst;The results show that the photocatalytic reaction kinetics of Methylene blue dye treated by Mn-Bi₂O₃/tourmaline composite catalyst was in accordance with the first order kinetics model:C_t=C₀exp(0.0786M^1.0231C₀^-0.9857H^-1.6024)...