Fluorine and phosphorus co-doped TiO2(001) nanosheets as a high-stability visible light-driven photocatalyst

Efficient use of TiO2/solar photocatalytic technology to degrade organic pollutants is one of the most safe and economical methods. However, in the TiO2 photocatalytic system, the visible light utilization efficiency and recycling stability of TiO2 are still low. We herein propose a dual-ions (F and P) co-doping method based on the charge compensation effect between Px+ and F−, which can remarkably improve the efficiency and stability of TiO2. The visible light degradation rate constant of optimized FP3-TiO2 (001) can reach 14 times of that of original TiO2 (001). Even under simulated environmental relevant conditions, FP3-TiO2 (001) still exhibits an excellent photocatalytic performance. The results of electron paramagnetic resonance, UV-Visible diffuse reflectance spectroscopy, and photoluminescence spectrum proved that the synergistic effect of doping F and P3 on TiO2 (001) greatly improved the efficiency of visible light absorption and photo-generated charge separation. Notably, FP3-TiO2 (001) had an excellent recycling and environmental stability, which may be attributed to the newly formed TiⅣ-OOH on the surface and the continuous shift between it and its exited state ([TiⅣ-OOH]*). This study proposes a novel strategy to considerably enhance the photocatalytic activity of TiO2 and provides insights into the photochemical interactions of multiple atoms and valence states.