High-Yield Synthesis of Periodic Mesoporous Silica Rods and Their Replication to Mesoporous Carbon Rods
✍ Scribed by C. Yu; J. Fan; B. Tian; D. Zhao; G.D. Stucky
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 173 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0935-9648
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✦ Synopsis
Periodic mesoporous materials [1] with variable compositions and controllable morphologies have been receiving much attention because of their versatile uses in separation, catalysis, nanoreactors, and sensors. [2,3] With the development in synthesis strategies during the last few years, mesoporous materials in the form of metal oxides, [2] metals, [4] and hybrid organosilicas [5] have been synthesized. Recently, progress in the study of mesoporous carbon [6±12] synthesized from periodic silica templates has been achieved; and such carbon materials are quite useful in gas separation, catalysis, and energy storage. [13,14] For a variety of practical applications, the fabrication of desired morphologies is important as well as the control in composition, structure, porosity, etc. Mesostructured films, [15] monoliths, [16] fibers, [17,18] spheres, [19] and crystal morphologies [20] have been obtained for silica and organosilicas by using commercial non-ionic block copolymers as supramolecular templates. [21,22] Until now, however, no successful morphology control in mesoporous carbon has been reported mainly for two reasons. First, the morphology of mesoporous carbon depends on its silica template; thus, the yield of mesoporous silica templates with desired morphology must be high. Secondly, since the reconstruction from silica templates to mesoporous carbon is accompanied by several steps with strict conditions such as high-temperature treatment (up to 900 C) and critical chemical reactions to remove the silica templates, the hydrothermal and thermal stability of mesoporous silica templates must be high in order to obtain order in both mesostructure and morphology of the templated mesoporous carbon. Herein we report an inorganic salt synthesis approach [17,19] for highly ordered, highly condensed mesoporous SBA-15 [21,22] with high yield (» 100 %) rod-like morphology and relatively uniform length (1±2 lm). Hexagonally ordered rod-like mesoporous carbon CMK-3 [8] has been obtained with high yield of a specific morphology utilizing these SBA-15 rods as templates. Such CMK-3 has a large surface area (up to 1823 m 2 g ±1 ) and