Controlled synthesis of titanium dioxide nanoparticles in a modified diffusion flame reactor

Titanium dioxide (TiO2) nanoparticles were synthesized by the oxidation of titanium tetrachloride (TiCl4) in a modified diffusion flame reactor. The reactor utilized a multiport diffusion type burner composed of 5 concentric tubes. The flame configuration was (Ar + TiCl4)/Ar/H2/O2/air producing several tens of grams of TiO2 nanoparticles per hour. Flame characteristics of the diffusion flame at the modified burner outlet were investigated. TiCl4 concentration and flow rates of combustion gases such as oxygen, hydrogen and air were chosen as key experimental variables for the control of the particle size and phase composition. TiO2 nanoparticles ranged from 10 to 30 nm in average particle diameter, and the mass fraction of anatase synthesized was 40 to 80% in all experiments.