Low-temperature formation of nanocrystalline β-SiC with high surface area and mesoporosity via reaction of mesoporous carbon and silicon powder

We report here a new route to prepare nanocrystalline beta-silicon carbide with high specific surface areas and mesoporosity. The preparation method was via the reaction of ordered mesoporous carbons (OMCs, carbon replicas of MCM-48, SBA-15 and KIT-6) with silicon powder at the temperature of 1200-1300 degrees C, which is below the melting point of silicon, 1420 degrees C. The SiC samples were characterized by XRD, SEM, TEM, N-2 adsorption and other techniques, which showed that the SiC samples were nanocrystalline and had a high surface area of up to 147 m(2) g(-1) and a mesoporosity in the range of 5-40 nm. In addition, the silicon vapor infiltration method at a temperature beyond 1420 degrees C was also brought into comparison. (c) 2005 Elsevier Inc. All rights reserved.