Low temperature synthesis of mesoporous silicon carbide via magnesiothermic reduction

Mesoporous silicon carbides (SiC) with high surface areas (above 300 m²/g) have been prepared successfully at a relative low temperature of 650 °C via magnesiothermic reduction of mesoporous silica/carbon (SiO₂/C) composites. The physicochemical properties and the structure of the products were characterized by various techniques such as XRD, FT-IR, SEM, TEM and N₂ adsorption-desorption isotherm. The experimental results indicate that the obtained SiC materials by this new method have similar structure to corresponding silica matrix templates. It was found that the magnesium (Mg) plays an important role in determining the structure and properties of the final products, which is used as a dual role agent both reducer and catalyst. The formation mechanism of mesoporous SiC has been also discussed.