This works employed K2Ti4O9, a novel Ti source, to prepare TiO2 powders. By a "low-temperature dissolution-reprecipitation process" (LTDRP), rutile phase TiO2 was successfully synthesized after reacting at 50 degrees C for 48 h. The obtained sample showed a specific surface area about 45 m(2)/g, and excellent activity in photo-destruction of NOx gas. The coupling of rutile phase TiO2 with commercial anatase TiO2 showed significant effect in further enhancing the photocatalytic activity. (C) 2009 Elsevier Ltd. All rights reserved.