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

Abstract

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 °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.