Synergistic effect of Mott-Schottky junction with oxygen defect and dramatically improved charge transfer and separation of Bi@Bi-doped TiO2

Abstract From viewpoint of engineering application, to dramatically enhance the photocatalyst performance is the absolute truth for solar energy photocatalysis. Although various modification strategies have been developed to enhance the activity of a photocatalyst, the improvement extent is actually not obvious with a single strategy. In this work, abundant bismuth is used to obtain the Bi-doped TiO2 (Dx), Bi@TiO2 (Sy) and Bi@Bi-doped TiO2 (SyDx) samples. Compared with original TiO2, the activities of Dx and Sy can only increase by 0.26 and 1.9 times under UV light irradiation (λ≤ 400 nm), respectively; however, the degradation activity of S10D1 has increased by 4.5 times, showing an obvious synergistic effect between Mott-Schottky junction and oxygen defect, in which oxygen defect and Mott-Schottky junction obviously expands the light adsorption range and promotes reduces the charge transfer and separation. To the best of our knowledge, the abundant, environmental-friendly bismuth-based Bi@Bi-doped TiO2 has not been reported so far. The simple integration strategy is remarkably efficient to greatly enhance the photocatalytic activity, compared to single strategy.