Hierarchically-structured SiO-Ag@TiO hollow spheres with excellent photocatalytic activity and recyclability.

A new protocol for constructing sandwich-like SiO-Ag@TiO hollow spheres (SAT) is introduced, in which SiO acts as an efficient support for the Ag nanoparticles (Ag NPs) immobilization, while TiO maintains its hierarchical structure and prevents the aggregation of Ag NPs during the photocatalytic reaction. As a photocatalytic agent, the inner and outer surfaces of TiO can be fully occupied by pollutants molecules because of its unique structure, which faster boosts the photo-generated electrons to transfer the substrates, leading to an enhanced photocatalytic performance. Compared with Ag NPs deposited on the surface of SiO@TiO (STA), the as-synthesized SAT exhibits a markedly enhanced visible-light and UV light activity than STA for degrading tetracycline and traditional dyes.