TiO2 shows photocatalytic activity only under UV light (3.2 ev band gap) that constitutes ∼ 5% of the total incident solar energy. A high throughput flame synthesis technique for production of visible-light-active oxygen deficient titanium dioxide (TiOx with x < 2) photocatalysts is presented. TiOx nanoparticles are synthesized by controlling the oxygen concentration in the particle formation zone in a diffusion flame aerosol reactor equipped with a flame quenching system utilizing titanium tetraisopropoxide as a precursor. The absorption spectra of the particles clearly demonstrated light absorption in the visible region. The visible light photocatlytic activity of TiOx particles is demonstrated by degradation of methyl orange solutions under visible light illumination. Flame aerosol reactors provide a single step process for synthesis of nanostructured TiO2 for visible light activated applications. This is an abstract of a paper presented at the AIChE Annual Meeting (Salt Lake City, UT 11/4-9/2007).