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

Abstract

It is well-known that TiO 2 nanoparticles are highly efficient photocatalysts in decomposing organic substance in wastewater, especially when they are used in suspension state. However, if TiO 2 nanoparticles cannot be withdrawn and reused, it is difficult to apply them in purification of wastewater due to the economic consideration. In present work, TiO 2/ SiO 2/ Fe 3 O 4 core-shell magnetic nanoparticles, constituted by Fe 3 O 4 core, SiO 2 intermediary layer and the TiO 2 out-shell, have been prepared and applied in photocatalytic degradation of a modulated methylene blue containing water. The results indicate that the as-prepared TiO 2/ SiO 2/ Fe 3 O 4 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 P 25 TiO 2 nanoparticles in the same reaction condition, it has been found that as-prepared TiO 2/ SiO 2/ Fe 3 O 4 nanoparticles exhibit similar photocatalytic activity to commercial P 25 TiO 2 nanoparticles in the photocatalytic degradation of methylene blue containing water. But the TiO 2/ SiO 2/ Fe 3 O 4 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 TiO 2/ SiO 2/ Fe 3 O 4 nanoparticles can be significantly reduced through reuse of the photocatalyst. It implies that TiO 2/ SiO 2/ Fe 3 O 4 nanoparticles possess the potential for industrial application.