Self-cleaning performance of nano-TiO2 modified metakaolin-based geopolymers

Geopolymer is an alternative binder to Portland cement. In this paper, nano-TiO2 was incorporated into a metakaolin-based geopolymer matrix to impart photocatalytic properties into the binder. The self-cleaning performance of the resulting binders was revealed under UV and direct sunlight irradiation. The effects of nano-TiO2 inclusion on compressive strength, microstructure, solar reflectivity, wettability, and decomposition of Rhodamine B (RhB) of the resulting binder were reported. Results showed the compressive strength, total solar reflectance (TSR), and photoinduced hydrophilicity and contaminate decomposition of geopolymer increases with TiO2 dosage. TiO2 particles mainly act as fillers to densify the binder. The resulting TiO2 metakaolin geopolymer has a compressive strength of 61 MPa and a surface TSR of 72%. The addition of TiO2 imparts photocatalysis properties into the geopolymer, which activates super-hydrophilicity of the surface and assist in the complete decomposition of RhB dye after direct sunlight exposure.

Automated summary

Incorporating nano-TiO2 particles into geopolymer can enhance the material's compressive strength, total solar reflectance, photoinduced hydrophilicity, and contaminant decomposition properties. TiO2 acts as fillers in geopolymer, densifying the binder and improving its overall performance.