Synthesis of SiO2 nanoparticles from sprayed droplets of tetraethylorthosilicate by the flame spray pyrolysis

Synthesis of silica (SiO2) nanoparticles from sprayed droplets of tetraethylorthosilicate (TEOS) by the flame spray pyrolysis was investigated, and the particles were characterized by TEM, XRD, and BET method. TEOS concentration, maximum flame temperature, and residence time of reactants in the flame were chosen as key experimental variables for the control of the particle morphology, and average particle diameter. Spherical SiO2 nanoparticles ranged from 12 to 47 nm in average particle diameter were produced by through all the experiments. As the TEOS concentration in the flame increased, the average particle diameter of the SiO2 nanoparticles having narrow size distribution increased. Larger SiO2 nanoparticles were synthesized as hydrogen and oxygen flow rate decreased in the flame, respectively. Average particle diameter increased as the residence time of the precursor increased by controlling of carrier gas flow rate. Crystal structure of all the product SiO2 nanoparticles was found as amorphous.