Photothermal porphyrin-based covalent organic framework for efficient removal of perfluoroalkyl substances

Temperature is vital to the removal ability of adsorbent materials. The application of convenient and energy-efficient light-induced heating to promote the removal of emerging contaminants are rarely reported. Here, we report synthesis of a photothermal porphyrin-based COF (Por-MA) for efficient removal of perfluoroalkyl substances (PFASs) in environment water. The crystalline Por-MA with rich nitrogen and ordered structure can provide electrostatic and hydrogen bonding interactions for adsorption of PFASs, further gave a large adsorption capacity (686.6 mg g−1) and rapid adsorption kinetics (equilibrium time < 10 min) for perfluorooctanoic acid (PFOA) at 25 °C, outperforming several other COF-based sorbents. Moreover, endothermic adsorption of PFOA on Por-MA made promoting adsorption of PFASs on photothermal Por-MA with facile illumination possible. Removal efficiencies of PFASs on Por-MA in environmental water samples also significantly improved with LED irradiation, indicating the high potential of photothermal COFs for removal of contaminants in practical water.