Characterization and photocatalytic performance of cement mortars with incorporation of TiO 2 and mineral admixtures

• Published in: Environmental science and pollution research international Vol. 30; no. 42; p. 95537
• Main Authors: Lara, Rancés Castillo, de Castro Xavier, Gustavo, Canela, Maria C, Carvalho, Juliana Alves, Alexandre, Jonas, de Azevedo, Afonso Rangel Garcez
• Format: Journal Article
• Language: English
• Published: Germany 01-09-2023
• Subjects: Bentonite; Minerals; Titanium - chemistry; Water; Nano-TiO2; Photocatalytic efficiency; Scanning electron micrographs; Cement mortar characterization
• ISSN: 1614-7499

As the main components of the building envelope, construction materials have a straight relation with air contaminants from anthropogenic origins. Titanium dioxide has been recently applied in construction industry products since its photocatalytic properties can be used for pollutant degradation purposes. This study evaluated the performance of cement-based mortars with the incorporation of TiO
nanoparticles and mineral admixtures. Six mortar compositions were defined by considering two reference mixes (with and without TiO
incorporation), two mineral admixtures (bentonite and metakaolin) as partial cement replacement and one waste from ornamental stone processing in two levels of partial substitution of natural sand. Consistency index, density, and entrained air content of mixtures were investigated at fresh state. Compressive strength, water absorption, sorptivity, and micrographs from scanning electron microscopy were used to characterize mortars at hardened state. It was observed that incorporation of TiO
does not considerably change mortar's properties at fresh and hardened state, despite a denser microstructure and improved interfacial transition zone. In general, the relation between the water-to-cement ratio and porosity on the performances of TiO
-added mortars was shown, which is strongly related to their photocatalytic efficiency. Metakaolin mixtures were more efficient to NO conversion, and high selectivity was observed for the bentonite mortars.