Elaboration of porous silicon carbide by soft templating molecular precursors with semi-fluorinated alkanes

We present a novel soft templating approach (STA) for the elaboration of porous silicon carbide (SiC) in oxygen- and moisture-free atmospheres. In this method, the molecular precursor, 1,3,5-trisilacyclohexane (TSCH) which is in a liquid state at room temperature, is templated by a solid network of semi-fluorinated alkanes (SFA) that self-assemble directly in the former liquid. The obtained gel phase is then converted into a polysilane by the polymerization of TSCH molecules around the solid network of SFA. In a next step, the SFA are washed out from the polysilane, and the latter material is converted into SiC by calcination under argon atmosphere at 1000 degrees C. The resulting material possesses a granular structure with a macroporosity. This study validates STA as a sustainable and promising method to obtain porous and mesoporous SiC.