Effect of silica addition on thermal stability of heat treated flame synthesised TiO 2 nanoparticles

Abstract

The effect of silica addition on the thermal stability of flame synthesised TiO₂ nanoparticles was investigated. TiO₂ nanoparticles with varying silica content were prepared using hydrogen diffusion flames. Characterisation and measurement of photocatalytic ability of formed nanoparticles before and after the heat treatment were carried out. On the basis of transmission electron microscope images and particle diameters that were calculated from specific surface area data and X-ray diffraction patterns, it is believed that the addition of silica might interrupt the growth of smaller particles to larger ones in the flame, but could enhance the thermal stability of the formed nanoparticles. Meanwhile, based on the decomposition of methylene blue, the anatase fractions and the calculated particle diameters, the TiO₂ nanoparticles that were synthesised with the addition of silica corresponding to 0·03 L min⁻¹ of the silica precursor carrier gas were the most thermally stable among those tested with heat treatment at 1000°C.