Photocatalytic cement : influence of TiO2 particle size on photocatalytic performances

The present work addresses the influence of titania (TiO2) particle size on the self-cleaning and depollution performances of photocatalytic white cement. Degradation of Rhodamine B (RhB), a red dye used to assess self-cleaning performances of concretes containing TiO2, as well as oxidation of gaseous nitrogen oxides (NOx), atmospheric pollutants responsible for acid rains and photochemical smog, are investigated using two commercial titania samples in cement and mortar specimens: a microsized, m-TiO2 (average particle size 153.7 nm ± 48.1 nm) and a nanosized, n-TiO2 (average particle size 18.4 nm ± 5.0 nm). Experimental data on photocatalytic performances are discussed in relation to the chemical environment of cement and impacts on applications in structural concrete.