Surfactant-mediated synthesis of a novel nanoporous carbon-silica composite

A novel nanoporous carbon-silica composite with medium hydrophilicity is synthesized by a series of methods consisting of preexpansion of the interlayer of graphite oxide (GO) by surfactant intercalation, the intercalation of tetraethoxylsilane (TEOS) and its hydrolysis in the interlayer, followed by post carbonization to form a robust bridged/pillared network. High-resolution N-2 adsorption results show that carbonization at 823 K gives a composite having the highest specific surface area of more than 1000 m(2)/g with both microporosity and mesoporosity. Varieties of analytical results using DRIFT, NMR, XPS, and RAALAN spectra indicate that this composite contains small graphene sheets in its structure and its silicon components are silica particles with +4 valence. Morphology observation, thermal desorption, and other properties suggest the important roles of dispersion of GO in aqueous solution, preexpansion of GO interlayer, interlayer hydrolysis of TEOS molecules, and the carbonization condition in the formation mechanism of this nanoporous composite.