Enhanced visible-light harvesting of triazine-based covalent organic frameworks by incorporating FeⅢ-tannic acid complexes for high-efficiency photocatalysis

Triazine-based covalent organic frameworks (COFs) have recently emerged as a new class of photocatalysts for visible-light-driven photocatalytic reactions. However, the optical absorption edge of triazine-based COFs is usually below 550 nm, resulting in inefficient photocatalytic performance. Herein, a novel FeⅢ-tannic acid (FeⅢ-TA) complexes evenly coating a triazine-based COF (FeⅢ[email protected]) was prepared using a simple self-assembly process. The FeⅢ-TA significantly enhanced the optical absorption of TTB-TTA, especially in the λ > 600 nm region. Consequently, the composite photocatalyst exhibited a higher photodegradation rate of methyl orange (MO), corresponding to a 14-fold enhancement, compared with the bare TTB-TTA. Moreover, the degradation rate was 372 times higher under >600 nm light illumination, indicating that the photocatalytic enhancement mechanism primarily came from the enhanced visible-light harvesting capacity of FeⅢ-TA. This work offers a promising avenue for enhancing the visible-light absorption of triazine-based COFs and providing insights into the research of high-performance photocatalysts.