A BODIPY-Containing Covalent Organic Framework as a Highly Porous Photosensitizer for Environmental Remediation and Pollutants Adsorption

The direct incorporation of borondipyrromethene (BODIPY) subunits into the structural backbone of covalent organic frameworks (COFs) gives facile access to porous photosensitizers but is still a challenging task. Here, we introduce β ketoenamine-linked BDP TFP COF, which crystallizes in AA stacking mode with hcb topology. A comprehensive characterization reveals high crystallinity and enhanced stability in a variety of solvents, excellent porosity (SABET = 1042 m2/g), broad light absorption in the visible region, and red emission upon the exfoliation of few-layer COF nanosheets. The versatility of multifunctional BODIPY-COFs is highlighted in various applications. Pollutants Bisphenol A (BPA, qmax = 426 mg/g) and Methylene Blue (MB, qmax = 96 mg/g) have been efficiently removed from H2O. Fluorescence quenching or enhancement of exfoliated BDP TFP COF nanosheets have been utilized for dual-mode sensing of MB or NEt3, respectively. Ultimately, the photosensitizing effect of the BODIPY units is retained in the COF. Thus, BPD TFP COF was established as a metal-free triplet photosensitizer, which efficiently oxidized a mustard gas simulant under visible light irradiation.