Fabrication of nanoporous silica nanospheres and nanotubes by inorganic and organic double templates

Inorganic and organic double templates were used to fabricate silica nanospheres and nanotubes with nanochannels perpendicular to the shells. Sphere and needle like CaCO3 nanoparticles, synthesized by a high gravity reactive precipitation method, were used as inorganic templates and C16H33N(CH3)(3)Br (C-16-CTAB) was used as an organic surfactant template. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were employed to characterize the nanoporous structure. The nanochannels were found perpendicular to the surface of nanospheres and nanotubes. The size of nanochannels is about 3-5 nm. The size of hollow nanosphers and nanotubes can be controlled by the inorganic CaCO3 nanoparticle templates and the nanochannels in the shells can be tuned by different surfactant micelles. The nanospheres and nanotubes with nanochannels perpendicular to the shells have a potential application in chemical bio-catalyst, bio-separation, and drug delivery.