Oxygen vacancies mediated Bi12O17Cl2 ultrathin nanobelts: Boosting molecular oxygen activation for efficient organic pollutants degradation.

Photocatalysis technology has been considered as a sustainable and promising strategy for pollutant degradation. However, the photocatalytic activity is limited by the unsatisfactory carrier separation efficiency of photocatalysts and insufficient reactive oxygen species. Herein, the oxygen vacancies (OVs) mediated Bi12O17Cl2 ultra-thin nanobelt (ROV Bi12O17Cl2) was fabricated via solvothermal method. The surface oxygen vacancies can act as the 'electron sink' and boost charge separation. Thus, the ROV Bi12O17Cl2 shows superior photocatalytic performance, which is 2.72 and 4.52 times compared to deficient oxygen vacancies Bi12O17Cl2 (DOV Bi12O17Cl2) and Bulk Bi12O17Cl2 for colored organic pollutants degradation, respectively. Besides, the ROV Bi12O17Cl2 also displays excellent removal efficiency for refractory antibiotics, roughly 4.00 and 7.45 times compared to that of DOV Bi12O17Cl2 and Bulk Bi12O17Cl2, respectively. Furthermore, the intermediates for photocatalytic degradation were determined through HPLC-MS and the possible degradation paths of the target molecules were inferred. Capture experiment and ESR spectra confirmed that the •O2- played a vital role for the organic pollutant degradation. This work provides a new perspective for the design of advanced semiconductors for organic pollutants degradation.