THE PREPARATION AND APPLICATION OF MAGNETIC NANOPARTICLES WITH CORE-SHELL STRUCTURE

It is well-known that TiO2 nanoparticles are highly efficient photocatalysts in decomposing organic substance in wastewater, especially when they are used in suspension state. However, if TiO2 nanoparticles cannot be withdrawn and reused, it is difficult to apply them in purification of wastewater due to the economic consideration. In present work, TiO2/SiO2/Fe3O4 core-shell magnetic nanoparticles, constituted by Fe3O4 core, SiO2 intermediary layer and the TiO2 out-shell, have been prepared and applied in photocatalytic degradation of a modulated methylene blue containing water. The results indicate that the as-prepared TiO2/SiO2/Fe3O4 nanoparticles possess high photocatalytic activity and the methylene blue in wastewater can be degraded quickly. Through comparing with the photocatalytic performance of the famous commercial P25 TiO2 nanoparticles in the same reaction condition, it has been found that as-prepared TiO2/SiO2/Fe3O4 nanoparticles exhibit similar photocatalytic activity to commercial P25 TiO2 nanoparticles in the photocatalytic degradation of methylene blue containing water. But the TiO2/SiO2/Fe3O4 nanoparticles used in suspension state can be simply recovered from the liquid by using a magnet or a magnetic field. So the cost of wastewater purification by photocatalytic degradation with TiO2/SiO2/Fe3O4 nanoparticles can be significantly reduced through reuse of the photocatalyst. It implies that TiO2/SiO2/Fe3O4 nanoparticles possess the potential for industrial application.