Facile fabrication of three-dimensional mesoporous Si/SiC composites via one-step magnesiothermic reduction at relative low temperature

By converting modified silica aerogels to the corresponding silicon/silicon carbide (Si/SiC) without losing its nanostructure, three-dimensional mesoporous (3DM) Si/SiC composites are successfully synthesized via one-step magnesothermic reduction at relative low temperature (650   °C). The phase composition and microstructure of the resulting samples are measured by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Raman spectra, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). N 2 -sorption isotherms results show that the products have high Brunauer–Emmett–Teller (BET) specific surface areas (up to 656   m 2   g −1 ) and narrow pore-size distributions (1.5–30   nm). The composites exhibit a strong photoluminescence (PL) in blue-green light region (peak centered at 533   nm). We have set out work on the biocompatibility and enhancing PL of samples. As a result of excellent performances of the composites, it can be expected to have significant application in optoelectronics, biosensors, biological tracer and so on.