Preparation of mesoporous Si-C-O fibers with a narrow mesopore size distribution.

Mesoporous Si-C-O fibers were fabricated by air activation of a kind of carbon-rich SiC-C fibers at 600 degrees C. The SiC-C fibers were prepared from the hybrid precursor of polycarbosilane and pitch through melt-spinning, air curing and pyrolysis in nitrogen. The carbon content of the SiC-C fibers was 54.4 wt%, and decreased to lower than 25 wt% after activation for more than 5 hours. Meanwhile, the surface area increased up to 260 m2/g, with a narrow mesopore size distribution mainly in the range of 2-5 nm. The SiC-phase derived from the polycarbosilane and the C-phase derived from the pitch form a bicontinuous interpenetrating network, which plays an important role for the narrow pore size distribution.