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A mesoporous silica film (MSF, 20 × 20 mm in size) with 3D accessible mesopores (Fmmm symmetry) was synthesized on a current collector substrate, and then the entire pore surface was coated with an extremely thin carbon layer. The resulting carbon-coated mesoporous silica film (C/MSF), which well retains the continuous silica phase with its ordered mesopore network intact, has many advantages over conventional MSFs, porous carbons, or carbon electrodes. Thanks to the continuous carbon-coated layer, C/MSF is electrically conductive, and besides, it has remarkably better stability in an aqueous solution than MSFs. These features enable C/MSF to be used as a stable electrode in aqueous electrolyte solutions. In addition, C/MSF exhibits a much higher rate of performance as an electrode of an electric double layer capacitor than conventional powdery electrodes, indicating that the C/MSF electrode has excellent electrical conductivity, which can be ascribed to the continuous film shape of C/MSF. Another noticea...

The entire pore surface of FSM-16 type mesoporous silica was uniformly coated with a thin carbon layer by carbonizing pre-doped organic-alcohol molecules onto the pore surface. The thickness of the carbon layer was estimated to be extremely thin, i.e., it corresponds to only 1–2 graphene layers. Even after the carbon-coating, FSM-16 preserves its intrinsic ordered pore structure (hexagonal array of cylindrical pores) and still possesses high surface area of 530 m 2 g −1 , but its pore nature was completely converted into a hydrophobic one, which was revealed from a very small amount of water–vapor adsorption. We characterized the electrochemical properties of the carbon-coated FSM-16 together with the carbon-coated SBA-15 synthesized by using the same coating method. Both of them exhibited electric double-layer capacitance in 1 M H 2 SO 4 and 1 M NaCl, and the values of the capacitance per surface area are comparable to those of conventional activated carbons. We can thus conclude that the present carbon-coating changes the nature of mesoporous silicas from an insulator to an electrical conductor with their ordered pore structures unchanged, and the carbon-coated mesoporous silicas can be used as electrode materials with uniform pores.

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.