A study of silicon nitride nanotube synthesis at relative low temperature by thermal-heating chemical-vapor deposition method

Thermal-heating chemical-vapor deposition has been used to synthesize Si3N4 nanotubes by heating tetra-ethyl-ortho-silicate at 165 °C to get vapor to flow in and providing nitrogen gas to the reaction chamber as the source of Si and N, respectively. A stainless-steel wire was coiled as entangled wire scaffold with a pore size of 1 mm. The wire scaffold was placed in the middle part of the reaction chamber. Cr, Fe and Mo, contained in the stainless-steel, served as catalysts to provide in situ growth of Si3N4 nanotubes on the coil surface at a relative low reactant temperature (1000 °C) through the vapor-liquid-solid growth mechanism. Most of the nanotubes are end-closed by a metallic particle. All the nanotubes were identified as α-Si3N4 in crystal structure.