Effective dispersion of nano-TiO2 powder for enhancement of photocatalytic properties in cement mixes

Photocatalytic properties of nano-TiO2 can be effectively utilized in the removal of some of the environmental pollutants under UV irradiation. Cement based-coatings including nano-TiO2 for exterior surfaces of the buildings are therefore attracting increasing interests. Due to high agglomeration of nano-TiO2 in cement media, their photocatalytic activity is significantly diminished. Agglomeration of nano-TiO2 particles in cement mixes can be effectively avoided by suitable dispersion of the particles in lime-saturated water followed by an ultrasonication treatment, prior to mixing with cement. This effective dispersion along with the formation of CaTiO3, display enhanced photodegradation of Malachite Green solution from 45 to 15 min under UV irradiation. (C) 2012 Elsevier Ltd. All rights reserved.