Sol-gel TiO2 nanoparticles prompt photocatalytic cement for pollution degradation

TiO2 nanoparticles (TiO2NPs) prepared by the sol–gel method have been incorporated to cement paste with the aim of creating a photocatalytic system capable of compensating, through degradation of hazardous molecules, the envi- ronmental impact associated to the production of the clinker. Doping was carried out at different mass ratios with TiO2NPs precursor solutions within a fresh ce- ment paste, which was then characterized using scanning electron microscopy (SEM). The photocatalytic performance was evaluated by the degradation of Methylene Blue (MB) using a 125W UV lamp as irradiating source. Main cement properties such as hydration degree and C-S-H content are affected by TiO2NPs doping level. Cement containing TiO2NPs exhibited an increasing photocatalytic activity for increasing doping, while the pure cement paste control could hardly degrade MB. The kinetics of the system where also studied and their second order behavior related to microstructural aspects of the system.