Controllable Microemulsion Synthesis of Hybrid TiO-SiO Hollow Spheres and Au-Doped Hollow Spheres with Enhanced Photocatalytic Activity.

Hollow structures in TiO materials can enhance the photocatalytic properties by reducing the diffusion length and improving the accessibility of active sites for the reactants. However, existing approaches for preparing hollow TiO materials have two drawbacks that restrict their engineering applicability: first, a heavy reliance on templates to form a hollow structure, which makes the preparation laborious, complicated, and costly; second, difficult-to-achieve high crystallization while maintaining the small grain size in calcinated TiO, which is crucial for enhancing photocatalytic activity. Herein, a simple, effective method is proposed that not only enables the preparation of hybrid TiO-SiO hollow spheres without the template fabrication and removal process via microemulsion technology but also achieves both high crystallization and a small grain size in calcinated TiO at once through the calcination of amorphous TiO with organosilane at a high temperature of 850 °C.