F^- Serve as Surface Trapping Sites to Promote the Charge Separation and Transfer of TiO₂.

ABSTRACT: Finding an effective strategy to promote the charge transfer and separation of TiO₂ is urgently needed. Herein, a surface fluorination (F^-)-modified TiO₂ (denoted as TO-xF, where x represents the volume of HF added in the solution) catalyst has been prepared by a mild and facile post-treatment method. The changes induced by surface F^- on the morphological, structural, and surface electronic features and the charge separation and transfer efficiency of TiO₂ were specifically examined. Compared with pristine TO, TO-0.4F exhibits enhanced photocatalytic degradation of methyl orange and phenol, production of hydroxyl radicals, and photocurrent response. The enhanced photocatalytic activities of TO-0.4F can be attributed to the role of surface F^- as surface trapping sites in effectively boosting the charge transfer and separation processes, which is verified by the steady-state and time-resolved fluorescence spectroscopy, electrochemical impedance spectroscopy, Bode plot, transient photocurrent response, and open-circuit voltage measurements. This study emphasizes the role of surface F^- in promoting the charge transfer and separation and improving the photocatalytic activity of TiO₂.

SUBMITTER: Liu X 

PROVIDER: S-EPMC8717585 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature