Photocatalytic removal of methylene blue using titania- and silica-coated magnetic nanoparticles

Abstract

The scope of this investigation is the photocatalytic degradation performance of newly synthesized nanoparticles (NPs); namely; Fe _3 O _4 ; Fe _3 O _4 @TiO _2 and Fe _3 O _4 @SiO _2 . Non-thermal synthesis methods are used to synthesize the NPs and to explore the ferromagnetic properties of the photocatalysts. The synthesized NPs are characterized using TEM, XRD, FTIR, TGA, VSM, and surface area analysis techniques. The photocatalytic activities of Fe _3 O _4 and Fe _3 O _4 @SiO _2 NPs, put under solar irradiation, and Fe _3 O _4 @TiO _2 NPs, put under UV irradiation, are examined. The efficiency in degradation of Methylene Blue (MB) pollutant is shown to be the best for Fe _3 O _4 @SiO _2 NPs, then in Fe _3 O _4 NPs, and lastly in Fe _3 O _4 @TiO _2 NPs. The silica (SiO _2 ) coating on Fe _3 O _4 NPs significantly enhances the light absorption and is found to improve the MB degradation rate and the photoinduced charge generation and separation (i.e. it enhances the exciton lifetime). That makes the Fe _3 O _4 @SiO _2 NPs promising candidates for organic pollutants removal in various environment-related applications.

Keywords

• Fe3O4@TiO2
• Fe3O4@SiO2
• photocatalytic degradation
• methylene blue
• magnetic nanoparticles