Pre-hydrolysed ethyl silicate as an alternative precursor for SiO2-coated carbon nanofibers

This work reported basically aims at understanding the extent of SiO2-coated carbon nanofibers using two different sol-gel precursors for the silicate glass. The silicate precursors employed were tetraethoxysilane (TEOS) and pre-hydrolysed ethyl silicate. The first route consisted in an acid hydrolysis and polycondensation of the TEOS and the second one in a polycondensation of the pre-hydrolysed ethyl silicate. The techniques of Fourier Infra Red spectroscopy, thermogravimetric analysis, scanning electron microscopy and X-ray diffraction were used to characterize the materials obtained. Both kinds of SiO2 precursor can coat the CNF effectively. However, the use of pre-hydrolysed ethyl silicate (faster gelation times and higher surface areas) can be considered a low-cost and facile alternative with respect to the use of TEOS, to obtain industrially silica-coated carbon nanofibers.

► SiO2-coated CNFs were obtained using two sol-gel precursors. ► TEOS and pre-hydrolysed ethylsilicate can coat the CNF effectively. ► Pre-hydrolysed has faster gelation times and higher surface than TEOS. ► The use of pre-hydrolysed can be considered an alternative to TEOS.