The Magnetic Visible-light-response Photocatalyst: Synthesis And Catalyzing

Photocatalytic oxidation is a new type of advanced water treatment technology with theadvantage of low energy consumption, simple process, easy operation, and without secondarypollution. As a kind of semiconductor photocatalyst TiO2draw the attention of researchers,while it can only absorbs4%of the sunlight due to the wide forbidden band of it,simultaneous recovery is difficult, which serious limits its use. Therefore, modify TiO2orexploit new type photocatalyst with response of visible light received extensive attention ofthe researchers. The key of this study is research a kind of special morphology photocatalystwith highly magnetic and optical response.In this study, the magnetic Fe3O4particles were prepared by hydrothermal method. Thesol-gel method was implied to coat SiO2layer on the surface of Fe3O4to protect the magneticand stability of it. Prepared Fe3O4@SiO2/Bi2SiO5、 Fe3O4@SiO2@TiO2andFe3O4@SiO2@TiO2@Bi2O3composite photocatalyst via the method of hydrothermal andsol-gel.The morphology, structure and optical properties of the composite were characterized byXRD, SEM, IR, XPS and DRS. The photocatalytic performance of the composite materialwere analyzed via the degradation of reactive brilliant red X-3B under the irradiation ofsimulated sunlight and ultraviolet.The analysis shows that the as-prepared Fe3O4and Fe3O4@SiO2were sphericalnanoparticles, the size distribution and dispersed were quite uniform, and the averagediameter was about200and240nm, respectively.The obtained Fe3O4@SiO2/Bi2SiO5samples that prepared under the optimized conditions,present strips structure built from several of braid shape, which was formed of delicatefiber-shaped structure braiding together to form the sheet-shape, then they piled up together toform the ultimate strips structure with a length of10-15um, width of6-8um and a thicknessof0.8-1um. In addition, the nanoparticle Fe3O4@SiO2attached on the surface of Bi2SiO5orembedded in the Bi2SiO5steady. Under visible light and ultraviolet irradiation, thedegradation rate of reactive brilliant red X-3B was65.4%and99.6%, respectively. The obtained Fe3O4@SiO2@TiO2and Fe3O4@SiO2@TiO2@Bi2O3composite materialprepared by sol-gel method, alternative were spherical nanoparticles structure. The sizedistribution and dispersed were quite uniform, and the average diameter was about300and350nm, respectively. The surface of the Fe3O4@SiO2@TiO2@Bi2O3particles was moresmoothly. Under visible light irradiation, the degradation rate of reactive brilliant red X-3Bwas56%and76.8%, respectively. While the reactive brilliant red X-3B was almostcompletely degraded under UV irradiation.The repeated experiments showed that the prepared Fe3O4@SiO2/Bi2SiO5、Fe3O4@SiO2@TiO2and Fe3O4@SiO2@TiO2@Bi2O3photocatalyst with highly stability andreusability.And present higher photocatalytic activity to compare with pure TiO2.