Manuel Luna

Air pollution, a major health concern, necessitates innovative solutions such as TiO₂-based photocatalytic building materials to combat its harmful effects. This study focuses on developing high-performance TiO₂ photocatalysts for NO_x removal in building applications, aiming to overcome the limitations of commercial TiO₂. These photocatalysts were synthesized via a hydrothermal method, with parameters such as synthesis time and post-treatment investigated to optimize their properties. Hydrothermal synthesis yielded TiO₂ nanoparticles with reduced aggregation and a high proportion of elongated particles with exposed {010} facets. This resulted in significantly enhanced photocatalytic activity compared to commercial P25 in methylene blue degradation and NO_x depollution. Subsequently, the optimized hydrothermal TiO₂ was successfully integrated into a silica sol–gel coating for application on building materials. The coated concrete demonstrated significantly higher NO_x removal efficiency and lower NO₂ release, achieving a 1.7-fold improvement in overall NO_x removal and significantly higher depolluting effectiveness compared to its P25 counterpart. These findings highlight the potential of hydrothermally synthesized TiO₂ with controlled morphology for the development of high-performance, environmentally friendly building materials with enhanced air purification capabilities.