Visible light responsive rutile TiO2 photocatalysts mixed with cement: Enhancement effect driven by TiO2/cement interfaces

[Display omitted] •Rutile TiO2 particles (A-P25 and R996) and their cement-mixed counterparts (A-P25/cement and R996/cement) towards NO oxidation were examined under visible light.•Photocatalytic activities and NO3– selectivity of TiO2/cement composites are much higher than respective values of its counterparts without cement.•Mixing TiO2 and cement did not influence geometric and optical properties and chemical oxidation state of TiO2.•Lattice distortion of TiO2 in the vicinity of cement results in modified adsorption/desorption properties of NOx molecules, resulting in enhances in photocatalytic activity. Naked rutile TiO2 as well as commercial rutile TiO2 with Al2O3 and ZrO2 capping layers both with particle size of 100 ~ 300 nm were tested as additives to cements with a goal of fabricating building materials that can remove harmful NO and volatile organic compounds from the atmosphere. The commercial TiO2 is widely used as pigment and very cost-effective. Generally, the activities of photocatalysts were enhanced by mixing with cement. Moreover, originally less active capped TiO2 yielded comparable or even superior activity than bare rutile in the composite with cement. Our results suggest that the activity of the photocatalyst/cement is overwhelmingly governed by the active TiO2/cement interfaces rather than the intrinsic surface structural properties of photocatalysts. Based on various analyses results including x-ray absorption spectroscopy, emphasis is placed on the unique adsorption properties of the interface sites, which are driven by the lattice distortion of TiO2 at this interface.