Magnetically recoverable core–shell nanocomposites γ-Fe2O3@SiO2@TiO2–Ag with enhanced photocatalytic activity and antibacterial activity

In this study, we synthesized γ-Fe2O3@SiO2@TiO2–Ag nanocomposites with a core–shell structure using a hydrothermal method and a sol–gel method. Transmission electron microscope images showed that the γ-Fe2O3@SiO2@TiO2–Ag nanocomposites had a core–shell structure. Photocatalytic examination of the γ-Fe2O3@SiO2@TiO2–Ag was carried out using methyl orange solution under UV irradiation. The γ-Fe2O3@SiO2@TiO2–Ag nanocomposites showed stronger photocatalytic activity than pure TiO2. With γ-Fe2O3@SiO2@TiO2–Ag, about 84% of the methyl orange was decomposed after 1 h of UV irradiation, versus 49% for pure TiO2. The antibacterial activity of γ-Fe2O3@SiO2@TiO2–Ag nanocomposites was remarkably greater than that of bare TiO2 nanoparticles. The introduction of silver nanoparticles into the TiO2 matrix facilitates charge separation by trapping photo-generated electrons, thereby enhancing biological activity and photoactivity.

Graphical abstractTEM images of the γ-Fe2O3@SiO2@TiO2–Ag with different amount of the Ti(OC4H9)4: (a) 0 g, (b) 0.75 g, (c) 1.5 g and (d) 2.25 g the γ-Fe2O3@SiO2@TiO2–Ag nanoparticles have a particle size ranging from 230 to 300 nm and that the particles retain a spherical morphology, non-aggregation, and a rough surface at all TiO2 contents. As the amount of Ti(OC4H9)4 increased, the thickness of the TiO2–Ag layer increased.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► γ-Fe2O3@SiO2@TiO2–Ag have been synthesized by hydrothermal method and sol–gel method. ► γ-Fe2O3@SiO2@TiO2–Ag showed the photocatalytic activity higher than the pure TiO2. ► γ-Fe2O3@SiO2@TiO2–Ag showed the antibacterial activity higher than the pure TiO2.