Carbon-coated mesoporous silica with hydrophobicity and electrical conductivity

Abstract

The pore surface of mesoporous silica SBA-15 was coated with 2,3-dihydroxynaphthalene (DN) through a dehydration reaction between the surface silanol groups in SBA-15 and the hydroxyl groups of the DN molecules. By the carbonization of DN in the SBA-15 pores, the pore surface was uniformly covered with an extremely thin carbon layer, which comprised only 1–2 graphene sheets. The resulting carbon-coated SBA-15 still possessed the characteristics of the original SBA-15—large surface area and pore volume, long-range ordered structure, and sharp mesopore size distribution. In addition, the carbon-coated SBA-15 showed marked hydrophobicity and high electrical conductivity, both of which are not intrinsic properties of SBA-15. The appearance of these features can be explained from the almost perfect carbon coating on the pore surface. Newly developed graphene coating technique can donate characteristic carbon properties to mesoporous silica.