The Preparation Of Magnetic TiO₂Photocatalyst And Its Degradation Of Dye Wastewater

Environment pollutants can be disposed efficiently by photocatalysts which can utilize renewable solar energy, and achieve the purpose of controlling and improving the environment. Photocatalytic technology has been aroused extensive attentions, and numerous researches have been made by researchers. TiO2has undoubtedly proven to be the most excellent photocatalyst for the oxidative decomposition of many organic compounds under UV irradiation due to its high catalytic efficiency, non-toxic, and no secondary pollution.However, TiO2is commonly used in the suspension system as powder which is difficult to be separated, the utilization rate of light energy is very low, and it’s easy to aggregate during the reaction. In this research, Fe3O4-TiO2magnetic photocatalyst was synthesized by the sol-gel method while the Fe3O4, which acted as a magnetic carrier, was prepared by coprecipitation. The samples were characterized by X-ray diffraction (XRD) and UV-visible diffuse reflectance (UV-Vis) and other methods. The photocatalytic activities of Fe3O4-TiO2magnetic photocatalyst were investigated by the initial concentration of10mg/L methylene blue (MB) as the simulation pollutants in this experimental. The experiments show that, the decolorization rate of MB can reach96.6%by Fe3O4-TiO2magnetic photocatalyst under light irradiation for90minutes, while the decolorization rate of MB is93.6%by TiO2. The recovery rate of Fe3O4-TiO2magnetic photocatalyst is about85.6%under an external magnetic field. The recovery rate of TiO2is about62.7%after10mins for centrifuge by10000r/min. So the Fe3O4-TiO2magnetic photocatalyst has achieved efficient recovery rate under ensuring the high catalytic activities.To enhance the photocatalytic activity of the Fe3O4-TiO2magnetic photocatalyst, the Ag/TiO2-Fe3O4magnetic photocatalyst were fabricated by the photochemical reduction method. The decolorization rate of MB (10mg/L) is about99.5%by Ag/TiO2-Fe3O4magnetic photocatalyst under light irradiation for90minutes. The recovery rate of the Ag/TiO2-Fe3O4magnetic photocatalyst is about85.2%under an external magnetic field which has no obvious decrease to the Fe3O4-TiO2magnetic photocatalyst, it indicates that the loading of Ag has no influence on the recovery efficiency of the photocatalyst, and can enhance the photocatalytic activity of the Fe3O4-TiO2magnetic photocatalyst.