High surface area microporous tabular SiO₂ nanoparticles synthesized from octylamine/water bilayer systems

Amorphous tabular SiO₂ nanoparticles were synthesized from the self-assembled octylamine/water bilayer via a template-directed growth mechanism. Morphology of the tabular SiO₂ nanoparticles was analyzed by transmission electron microscope (TEM) both for samples dried at 25 °C and as a function of high temperature treatment. The tabular SiO₂ nanoparticles had well-defined thickness (4-6 nm) with a relative range of face diameter from 100 to 300 nm. This range of dimensions leads to a wide distribution of aspect ratio (10-50) based on atomic force microscope analysis (AFM). High surface area up to ∼1200 m²/g was readily obtained with a very uniform micropore size of about 0.63 nm after thermal treatment at 700 °C for 2 h.