A magnetically recoverable photocatalyst prepared by supporting TiO2 nanoparticles on a superparamagnetic iron oxide nanocluster core@fibrous silica shell nanocomposite

Abstract

A magnetically recoverable photocatalyst was prepared by supporting TiO₂ nanoparticles on a superparamagnetic iron oxide nanocluster (SION) core@fibrous silica shell (FSS) nanocomposite. Using the raspberry-shaped magnetic iron oxide nanocluster core as a seed, FSS with uniform thickness was grown directly on the core surface by a sol–gel process. The preparation method was optimized to have a single core for each nanoparticle by adjusting the amount of the silica source. The FSS has a fanning structure of radial pores, which enable large amounts of TiO₂ nanoparticles to be supported easily on the pore surface. SION@FSS with amorphous TiO₂ loaded on the pores (SION@FSS@Am-TiO₂) was crystallized to the anatase phase (SION@FSS@A-TiO₂), which shows good photocatalytic effect. When used for water purification, SION@FSS@A-TiO₂ shows faster dye degradation kinetics than that of commercial P25 nanoparticles. The as-prepared SION@FSS@A-TiO₂ photocatalyst could be magnetically recovered easily from water after decolorization of the dye.