Fluorinated covalent organic framework materials for photocatalytically driven benzylamine coupling and azo dyes degradation

Abstract

Covalent organic frameworks (COFs) with pre-designed structures and superior photophysical properties have attracted significant attention due to their applications in photocatalysis. In this research, an imine-linked fluorinated 2D-COF (TFA-TTA-COF) material was feasibly fabricated from polycondensation of 2,3,5,6-tetrafluoroterephthalaldehyde (TFA) and 4,4′,4′'-(1,3,5-triazine-2,4,6-triyl)trianiline (TTA) in solvent-thermal methods. The TFA-TTA-COF material exhibited excellent crystallinity, high Brunauer-Emmett-Teller surface area of 1504 m2·g−1, and superior thermal and chemical stability. Considering the advantages of enhanced light absorption, effective charge separation and charge transfer, the prepared TFA-TTA-COF was employed as photocatalyst for the degradation of dyes. The degradation efficiencies of Eriochrome Black T (EBT) and Eriochrome Black A (EBA) dye in water could attain 89 % and 82 %, respectively. Furthermore, TFA-TTA-COF was found to show satisfactory photocatalytic performance with high conversion and selectivity in the photo-driven oxidative coupling of benzylamines. This work demonstrated the important contributions to the development of heterogeneous COFs-based photocatalysts.