Fabrication and characterization of mesoporous Si/SiC derived from diatomite via magnesiothermic reduction

Abstract

In the past few decades, SiC and Si have been widely researched via different methods due to their unique electrical conductivity, stable physical-chemical performance and good wear-resisting performance. In this paper, we firstly used diatomite as silica source and carbon powders as carbon source to synthesize mesoporous Si/SiC via magnesiothermic reduction reaction at relative low temperature (650 °C). All samples were characterized by XRD, SEM, TEM and N2 adsorption-desorption. The XRD patterns and TEM images confirmed that diatomite was fully transformed into Si and SiC. N2 adsorption-desorption isotherms shown that Si/SiC exhibited mesoporous structure. Brunauer-Emmett-Teller (BET) gas adsorption data showed that Si/SiC had a specific surface area of 69.09 m2/g and an average pore size about 10.82 nm. The results confirmed that diatomite can fully transformed into Si/SiC. The possible chemical reactions of magnesiothermic synthesis of mesoporous Si/SiC is also discussed.