Novel TiO2–Pt@SiO2 nanocomposites with high photocatalytic activity

Abstract

This article reports a facile and controllable two-step method to construct TiO₂–Pt@SiO₂ nanocomposites. TiO₂ nanoparticles (NPs), with small size and high surface energy, were synthesized by a solvothermal reaction process. The TiO₂–Pt@SiO₂ nanocomposites were fabricated by a reverse micro-emulsion method. SiO₂ shell coated NPs were adopted for further photocatalytic reaction. Because of their small size and high surface energy, TiO₂@SiO₂ and TiO₂–Pt@SiO₂ nanocomposites show higher photocatalytic activity than commercial Degussa P25. Compared with TiO₂@SiO₂, TiO₂–Pt@SiO₂nanocomposites have improved photocatalytic activity due to the Pt induced spatial separation of electrons and holes. The silica shells not only maintain the structure of the nanocomposites but also prevent their aggregation during the photocatalytic reactions, which is highly important for the good durability of the photocatalyst. This strategy is simple, albeit efficient, and can be extended to the synthesis of other composites of noble metals. It has opened a new window for the construction of hetero-nanocomposites with high activity and durability, which would serve as excellent models in catalytic systems of both theoretical and practical interest.