Aerosol-assisted synthesis of thiol-functionalized mesoporous silica spheres with Fe ₃O ₄ nanoparticles

Thiol-functionalized mesoporous silica spheres having Fe ₃O ₄ nanoparticles are fabricated in one-pot by aerosol-assisted synthesis. A TEM image shows that Fe ₃O ₄ nanoparticles are successfully embedded within the mesoporous silica spheres. SEM images and SAXS profiles reveals that the encapsulating Fe ₃O ₄ nanoparticles do not affect the ordering of a mesoporous structure. The spherical morphologies are also well retained. The presence of cage-type mesopores with uniform size is confirmed by N ₂ adsorption-desorption isotherms and TEM observations. The spray-dried thiol-functionalized particles with Fe ₃O ₄ nanoparticles effectively adsorb mercury (II) ions due to their strong interaction to thiol groups embedded in the framework. The particles with the amount of Fe ₃O ₄ nanoparticles (3.5 wt%) show a saturated magnetization (over 1.0 emu/g). This magnetic property is useful for practical collection with magnet.