TiO2 is one of the most widely studied photocatalysts during the past decades due to its ability to photo-oxidize harmful chemicals in both air and water to CO2 in the presence of UV light. TiO2 also shows promise for energy applications such as water splitting, as well as in photochemical solar cells. The relationship between fabrication conditions, TiO2 structure, and photocatalytic performances was elucidated. Sputter deposition provided excellent control of the phase and interface formation. Deposition incidence angle was the key factor of the study. Results of an investigation on the performance as photocatalytic surfaces, measured by degrading acetaldehyde in a closed batch reactor and compared to mixed phase TiO2 on glass slides fabricated by other method, are discussed. This is an abstract of a paper presented at the 2006 AIChE Annual Meeting (San Francisco, CA 11/12-17/2006).