Mesoporous Materials toward Nanofabricator and Nanoreactor

Abstract

Construction of nanomaterials has been developed from both top-down and bottom-up approaches. In these approaches, surfactant-templated mesoporous materials are promising because of their tunability, uniformity and reproducibility in both the size and shape of produced mesopores. Mesoporous silica materials have been widely and deeply investigated in the early stage, basing on the sol-gel chemistry of silicate. Although insulating mesoporous silica cannot be directly applicable to electrode materials, the mesoporous silica films and their hybrid films are recently applied as hard templates and electrodeposition of metals inside the mesopores realizes the formation of metal nanowire assembly, which has parallel orientation to the electrode surface. Furthermore, the mesoporous silica film with perpendicularly oriented mesochannels are prepared and used as hard-template, resulting in the fabrication of metal nanowire assembly standing on the electrode surface. On the other hand, conductive materials are recently fabricated as mesoporous structure by the surfactant-template method. Mesoporous carbon becomes the most conventional mesoporous conductive material and has been investigated as the electrode material mainly applicable to energy conversion. By introducing catalyst particles and ionomers inside mesochannels, triple phase boundary can be constructed and the application toward cathode electrode in the polymer electrolyte fuel cell (PEFC) has been investigated.