High surface area porous silicon carbide synthesized via sol-gel and carbothermal reduction process

摘要

A modified sol-gel method is proposed for the preparation of high surface area porous silicon carbide. In this method, furfuryl alcohol and tetraethoxysilane were used respectively as carbon and silicon precursors for preparing a carbonaceous silica xerogel. Polymethylhydrosiloxane (PMHS) was employed as pore-adjusting agent in the sol-gel process. SiC was obtained by the carbothermal reduction of the carbonaceous silica xerogel at 1300 °C in argon flow and then purified by removing excess silica, carbon and other impurities. XRD, FTIR, SEM, HRTEM and BET were used to characterize the SiC samples. The results show that the SiC products are found to have high specific surface area of 167 m~2 /g. PMHS has important effect on the surface area, pore volume of the SiC products. The SiC exhibits different photoluminescence properties.