FSP process is a gas phase combustion synthesis method enabling the production of a broad range of materials in the form of nanostructured powders with high specific surface area and primary particle size in the range of few nanometers.
FSP is based on the exothermic combustion of a spray of a metallorganic liquid precursor. By means of a suitable nozzle-equipped burner, a liquid-phase mixture containing a metallorganic compound and a solvent is dispersed into a flame where the resulting mixture droplets are combusted generating small clusters, which grow up by collisions and sintering processes taking place in the high temperature environment of the flame. An additional oxygen flow provides both the complete combustion of the solvent and the metallorganic compound in water and CO2. Due to the oxygen abundance and the high temperatures of the flame, FSP-made nanoparticles are typically fully oxidized and crystalline. Powders are collected by a suitable filtering system placed above the flame. No post-production treatment steps are required and the nanoparticles are ready to use.
FSP allows a precise control over the powder structural characteristics. Properties such as crystallite size, crystalline phase, degree of aggregation and agglomeration, surface area and porosity can be controlled by flame conditions. Multicomponent and doped nanoparticles can be synthesized by mixing different metallorganic precursors before feeding them into the spray nozzle.
FSP-made nanoparticles include a wide variety of metal oxides (e.g. TiO2, SiO2 and Al2O3), complex oxides (e.g. YSZ and ITO), noble metals and nanocomposites (e.g. alumina or titania supported Pt) that are of interest in a number of emerging applications (e.g. photocatalysis, sensors, batteries and solar cells).