Facile Synthesis of Yolk–Shell Nanostructured Photocatalyst with Improved Adsorption Properties and Molecular‐Sieving Properties

A novel and facile method to fabricate yolk–shell nanostructured photocatalysts consisting of TiO 2 nanoparticles (NPs) as the core and spherical hollow silica as the shell was developed. In the fabrication, commercial TiO 2 NPs were directly incorporated into hollow silica spheres by utilizing oil‐in‐water (O/W) microemulsions as a template, followed by heat treatment to create a void space between the TiO 2 core and the silica shell region. The synthesized yolk–shell nanostructured TiO 2 @SiO 2 acts as an efficient photocatalyst with both improved adsorption properties and photocatalytic efficiency, which far outperformed those of naked TiO 2 owing to the ability of the porous silica shell to adsorb/enrich small organic reactants (acetaldehyde and 2‐propanol) inside the void space and efficient transportation to the adjacent active TiO 2 core. Comparative photocatalytic tests using a large organic molecule (conalbumin) revealed that the porous silica shell with an average pore diameter of 2.0 nm endowed this material with a molecular‐sieving property, demonstrating its potential application in combination with organic support materials.