Fe Species Supported on Blue-TiO₂/WO₃ Nanocomposite as Catalyst for the Decomposition of Toluene Vapor under White Light-Emitting Diode Lighting

Photocatalytic nanomaterials for indoor air purification have garnered attention for the removal of aromatic compounds, including toluene, among volatile organic compounds (VOCs). However, there are still limitations that need to be addressed for the practical implementation of this technology, such as low efficiency under indoor lighting and the stability of photocatalytic nanomaterials under real atmospheric conditions. In this study, we present an nanoscaled iron-decorated blue TiO 2 /WO 3 Z-schemed catalyst that possesses the ideal band position for efficiently eliminating toluene. This catalyst generates reactive oxygen species, oxidizing toluene to benzaldehyde and ultimately converting it to CO 2 under visible LED light. The toluene removal efficiency continuous flow reaction system is five times higher than that of each catalyst under a constant airflow system. The introduction of nanoscaled iron at the interface and on the surface between BTO and WO 3 nanoparticles facilitates Z-scheme charge transfer, promoting the generation of reactive oxygen species (ROS) and effectively breaking down toluene via the Fenton reaction. The catalytic activity of BTO-Fe/WO 3 is maintained at over 92% efficiency, even after three recycling cycles. This study demonstrates that the hybridization of nanoscaled iron and semiconductors can decompose the stable toluene ring even under an ambient visible light, showcasing practical performance for feasible air purification in a common indoor environment system.