摘要 |
A mesoporous carbon film having a unimodal pore structure comprises a film of carbon defining an open network of interconnected primary pores arrayed in a uniform, random manner throughout the film. The pores in the film have an average pore diameter in the range of about 2 to about 3 nm, and the diameters of the pores have a substantially unimodal pore diameter distribution. Not more than about 20 % of the pores in the film have a diameter of less than about 1 nm. The mesoporous carbon films can be prepared by depositing a thin film of an aqueous sol-gel composition comprising a polysiloxane gel precursor, and a water soluble carbohydrate onto a substrate, heating the thin film to carbonize the carbohydrate and form a carbon/silica nanocomposite film, and removing the silica from the carbon/silica nanocomposite film to provide a continuous mesoporous carbon film. Suspending colloidal silica in the aqueous sol-gel composition prior to depositing the thin film on the substrate affords a mesoporous carbon film having a hierarchical, bimodal pore structure, which includes spherical secondary pores randomly distributed throughout the film and interconnecting with the network of primary pores. |