Antibacterial and Antifungal Characteristics of Hydroxyl Apatite Composite Material Coated on Nitrogen-doped TiO2 (HA/N-TiO2)

Photocatalytic technology using nano-material HA/TiO2 has been widely applied worldwide to treat pollutants, kill airborne gram-negative and gram-positive bacteria, and candida fungi, especially indoor air. In this study, HA/N-TiO2 material was synthesized with oxidation-reduction absorption properties and photocatalytic ability in the visible-light irradiation that helps reduce costs compared to using ultraviolet light (UV). The structure and morphology of the material were evaluated using XRD, SEM methods, showing HA/N-TiO2 has a spherical crystal structure, sharp, and uniform with particle sizes ranging from 10 to 30 nm. To assessment of the antibacterial and antifungal efficiency of the material, we inoculated the culture of microorganisms on 10x10 cm tiles coated with HA/N-TiO2 solution with the coating thickness of 0.3 µm. This coating thickness resulted in optimal antibacterial efficacy. With continuous fluorescent light 20 W exposure for 1-9 hours, up to 96-100% of inoculated bacteria were eliminated. In real-scale experiments on the wall surfaces, the quantity of bacteria and mold decreased by 20% after 30 days when treated with HA/N-TiO2 solution compared to the control sample. HA/N-TiO2 material has the potential to treat bacteria and fungi on a practical scale if there is further cost-benefit analysis extensive research.