Comparison of two soft chemistry routes for the synthesis of mesoporous carbon/β-SiC nanocomposites

Abstract

We compare the influence of using either molecular or colloidal precursors on the synthesis of a ceramic material containing SiC and porous carbon. Remarkably, the temperature of synthesis for crystalline SiC is independent of the route chosen. The excess carbon in the initial mixture is the source of the excess porous carbon that binds to the crystalline domains of SiC in the final products. Interestingly, increasing the initial area of surface contact between carbon and silicon in the ceramic precursor results in different porosities in the 'meso' range. Simultaneous control of the size and the relative amounts of Si and C in the precursors allows control to be exerted over the nature and texture of the final powders. A simple and general mechanism is herein proposed to explain the evolution of the surface area as a function of the volume fraction of residual carbon in the synthesised ceramic. © 2013 Springer Science+Business Media New York.