Nanoporous silica prepared with activated carbon molds using supercriticalCO2

Nanoporous silica materials have been prepared using an activated carbon as a mold and supercritical carbon dioxide as a solvent. Tetraethyl orthosili cate (TEOS) dissolved in supercritical carbon dioxide was in contact with t he activated carbon templates of various macroscopic shapes (fibers, granul es, powders). After the removal of activated carbon templates by calcinatio n in air or oxygen plasma treatment, microporous and mesoporous silica samp les replicating not only mesostructures, but also macroscopic shapes, of ac tivated carbon molds were obtained. The pore size of the silica replicas in creases with. increase in carbon crystallite size of activated carbon as es timated from XRD patterns.