The flame spray pyrolysis (FSP) is a fast (one step) and versatile process for the production of a wide variety of oxide nanoparticles. A homemade FSP set-up was constructed and utilized to synthesize TiO2 pure and composite materials.
Precursor solution is injected through the centre capillary of the FSP nozzle by a syringe pump at different rates. Oxygen is fed through the surrounding annulus as dispersion gas and a supporting CH4/O2 flame surrounding the oxygen gas annulus stabilizes the spray flame. A sintered metal plate ring provides an additional sheath flow (oxygen or nitrogen) surrounding the spray flame. The resulting powders are collected on glass microfiber filters with the aid of a vacuum pump. The relationship between the particle properties and the synthesis conditions (the combustion environment - excess or restrictive oxygen, the pump/precursor rate and the enthalpy combustion of the fuel) is studied
Although the surface specific area of the TiO2/perlite composites was lower than that of P25 sample, their photocatalytic activity in NO oxidation was comparable and even higher for some of them. This result was attributed to the presence of perlite glassy substrate that facilitates photocatalyst dispersion as well as to the synergistic effect between two crystalline phases.