Photodegradation of benzene at ppb levels by mixed-phase TiO 2 nanoparticles, synthesized by the oxidation of TiCl 4 in propane/air turbulent flame chemical vapor deposition (CVD) process, is investigated experimentally by using a tubular photoreactor with thin TiO 2 films coated on the reactor wall by sedimentation. Effects of inlet benzene concentration from 10 to 300 g/m 3 , rutile mass fraction from about 20 to 50% and photoluminescence (PL) intensity of TiO 2 nanoparticles on degradation degree are examined under the conditions of 70% relative humidity, 38 g/cm 2 catalyst loading, 24 mW/cm 2 UV irradiation of 254 nm and 5.7 s residence time in the reactor. Based on experimental results, separation of photo-induced electron (e- ) and hole (h + ) pairs by rutile phase is discussed as photo-induced electron (e- ) in anatase phase will migrate to rutile surface due to that the potential of conductive band of rutile is lower than that of anatase, leading to more holes ready on anatase surface for oxidation reactions. Photodegradation of benzene at ppb levels by mixed-phase TiO 2 nanoparticles, synthesized by the oxidation of TiCl 4 in propane / air turbulent flame chemical vapor deposition (CVD) process, is investigated experimentally by using a tubular photoreactor with thin TiO 2 films coated on Effects of inlet benzene concentration from 10 to 300 g / m 3, rutile mass fraction from about 20 to 50% and photoluminescence (PL) intensity of TiO 2 nanoparticles on degradation degree are examined under the conditions of 70% Based on experimental results, separation of photo-induced electron (e-) and hole (h + 2) at 25 g / ) pairs by rutile phase is discussed as photo-induced electron (e-) in anatase phase will migrate to rutile surface due to that the potential of conductive band of rutile is lower than that of anatase, leading to more holes ready on anatase surface for oxidation reactions.