Carbons As Scaffolds in Tuning the Morphology of Nanostructured Materials Using an Aerosol Based Process

A series of Fe₂O₃/SiO₂/C  microspheres are synthesized through a rapid aerosol based process, using carbon to direct nanostructure and morphology of the microspheres. Sucrose is used as carbon source and plays an important role in the morphological transformation of the microsphere from hollow structure to cage-like structure. At low sucrose concentration, solvent evaporation facilitates silicate condensation along the liquid-gas interface which seals the other species in the droplet to form a hollow space. At high sucrose concentration, polymerization and carbonization of sucrose prevent the diffusion of the species in the aerosol droplet, therefore silicate molecules condense throughout the aerosol droplet and form cage-like structure. The particles can be further engineered by etching SiO₂ or burning carbon off to form mesoporous Fe₂O₃/Carbon or Fe₂O₃/SiO₂ microspheres.