Versatile rattle-type magnetic mesoporous silica spheres, working as adsorbents and nanocatalyst containers

The well-defined rattle-type magnetic silica nanocomposite had been synthesized through a facile sol–gel process accompanied by a hard-template method. Structural characterizations indicated that the fabricated nanocomposite, denoted as γ-Fe₂O₃@SiO₂–@mSiO₂, was composed of nonporous silica-coating magnetic iron oxide encapsulated in mesoporous silica hollow sphere. The textural parameters of the nanocomposite are adjustable by controlling the preparation conditions. The unique structure of the prepared nanocomposite showed relatively high methylene blue adsorption capability and can be used for removal of dye from aqueous solution. In addition, some active metallic nanoparticles (such as Pt, Pd) can be introduced into the cavity of γ-Fe₂O₃@SiO₂–@mSiO₂ to construct confined integrated catalytic system. The designed Pt-based integrated nanocatalyst exhibited not only high activity and selectivity, but also an excellent reusability for the selective hydrogenation of nitrobenzol to aniline. The existence of magnetic core in the nanocomposite provides a facile separation from liquid solution.

Rattle-type nanocomposite with nonporous silica-coating magnetic iron oxide nanoparticles encapsulated in mesoporous silica hollow sphere had been prepared. This unique nanocomposite exhibits excellent adsorption capability for methylene blue dye. After loaded with Pt nanoparticles, the formed functional nanoreactor is very active for selective hydrogenation of nitrobenzol to aniline and shows outstanding reusability.