Synthesis of sol–gel titania bactericide coatings on adobe brick

This study presents the development and characterisation of transparent sol–gel TiO2 coatings based on titanium IV isopropoxide (TIP4), formed on a sustainable clay brick material (adobe). The sol–gel layers modified the surface of adobe, which can potentially lead to new functionalities enhancing adobe performance, e.g. higher water resistance and imparting bactericidal behaviour. X-ray diffraction results on synthesised TiO2 layers based on TIP4 showed that the film has characteristic peaks of anatase phase. Static SIMS analysis was used to detect the presence of TiO2 on adobe surfaces, which were also observed by TEM confirming their thickness to be in the range 20–50 nm. Sol–gel double SiO2–TiO2 layers were also deposited on adobe substrates. These coatings did not exhibit any cracks neither signs of peeling off from the substrate. The developed surface modified adobe bricks are attractive sustainable building materials.