Fe-Modified TiO₂ Photocatalyst for Effective Indoor Bacterial Inactivation Using LED Light: Toward Safer Disinfection...

Commercial TiO₂ P25 was modified with iron species using simple, mild and cost-effective synthesis conditions. The novel TiO₂-Fe material exhibits both high disinfectant activity and long stability under visible light irradiation. The bactericidal activity of the synthesized catalyst was assessed by its capability to inactivate Escherichia coli under both simulated solar and LED-visible light. XRD confirmed the structural integrity of the material, while diffuse reflectance spectroscopy evidenced its absorption in the visible region. Mössbauer and FTIR analysis of the TiO₂-Fe catalyst indicate that iron exists predominantly in the Fe³⁺ state in a Ti-O-Fe bond. Electrochemical studies allowed to correlate the reactivity with the conduction and valence band positions, providing insights into the production of reactive oxygen species (ROS) responsible for bacterial inactivation. A first noteworthy aspect of this study is the identified Ti-O-Fe bond in the TiO₂-Fe material, a feature that has not been previously reported in the literature. Another innovative aspect is the simplicity of the synthesis method, which employs a thermally mild and time-efficient process, thereby providing an efficient and accessible approach for enhancing photocatalytic properties. Our findings suggest that the prepared TiO₂-Fe photocatalyst holds potential for future applications in antimicrobial paint coatings designed for hospital environments, aiming to enhance infection control under indoor lighting conditions.