Aerosol-Assisted Synthesis of Thiol-Functionalized Mesoporous Silica Spheres with Fe₃O₄ Nanoparticles

Thiol-functionalized mesoporous silica spheres having Fe₃O₄ nanoparticles are fabricated in one-pot by aerosol-assisted synthesis. A TEM image shows that Fe₃O₄ nanoparticles are successfully embedded within the mesoporous silica spheres. SEM images and SAXS profiles reveals that the encapsulating Fe₃O₄ 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 N₂ adsorption-desorption isotherms and TEM observations. The spray-dried thiol-functionalized particles with Fe₃O₄ nanoparticles effectively adsorb mercury (II) ions due to their strong interaction to thiol groups embedded in the framework. The particles with the amount of Fe₃O₄ nanoparticles (3.5 wt%) show a saturated magnetization (over 1.0 emu/g). This magnetic property is useful for practical collection with magnet.