Synthesis of SiO2 Nanotubes and Their Application as Nanoscale Reactors

Abstract

SiO2 nanotubes could be synthesized by hydrolysis of tetraethyl orthosilicate (TEOS) on the surface of carbon nanofibers (CNF), followed by removal of CNF. In the synthesis of SiO2 nanotubes, CNF acted as templates. The wall thickness and the internal diameter of SiO2 nanotubes were changed by hydrolysis time of TEOS and the diameter of CNF templates, respectively. The catalysts for the hydrolysis of TEOS were functional groups on the surface of CNF. The methane decomposition was carried out over SiO2 nanotubes containing Ni metal particles, so that carbon nanotubes with uniform diameter (ca. 8 nm) were formed at the inside of SiO2 nanotubes. This result strongly indicated that SiO2 nanotubes worked as nanoscale reactors.