Development of functional TiO2 coatings deposited on cementitious materials

This present paper evaluates the functionality of different TiO2 coatings deposited on the exposed surface of Portland cement pastes. Cement pastes coated from a crystalline TiO2 suspension (CS) and an amorphous TiO2 solution (AS) were compared. Some samples with film deposition from AS were submitted to autoclave treatment. Film deposition was carried out by spin-coating with 1, 2, 3 or 5 coating layers. The coating morphology was observed by SEM and the possible presence of TiO2 crystalline phase was confirmed by XRD. Static water contact angle and RhB degradation were used to assess the photoinduced activity of the films. All the films deposited from CS exhibits both photo-induced superhydrophilicity and photoactivity. The samples coated from AS display only a minor increase in the rate of degradation of rhodamine B. The results suggest that the autoclave treatment did not favor the formation of crystalline TiO2 phases. (C) 2020 Elsevier Ltd. All rights reserved.