Synthesis of porphyrin and resorcinarene-based porous organic polymers for the superfast adsorption of bisphenol A and cationic herbicides

Abstract

The adsorption method for water pollutants has aroused significant attention owing to its convenience, simple operation, high efficiency, and cost-effectiveness. In this paper, a porous organic polymer (POP) namely POP-Por using porphyrin-based and resorcinarene-based molecules as the building block was successfully synthesized via Sonogashira coupling copolymerization, and was then sulfonated to prepare POP-SO₃⁻. POP-Por showed excellent adsorption performance towards bisphenol A (BPA) owing to the high BET surface area and the formation of hydrogen bonding and π–π interactions. The pseudo-second-order rate constant (k₂) of POP-Por towards BPA was 12.5 g mg⁻¹ min⁻¹ and the maximum adsorption capacity (Q_m) of POP-Por towards BPA was 780 mg g⁻¹. Meanwhile, POP-SO₃⁻ exhibited high adsorption affinity towards herbicides including paraquat and diquat due to the strong electrostatic interactions. k₂ of POP-SO₃⁻ towards paraquat and diquat were 31.4 and 68.6 g mg⁻¹ min⁻¹ (the removal efficiency can reach >96% when the contact time was only 10 s), surpassing those of most of the reported adsorbents. Q_m of POP-SO₃⁻ towards paraquat and diquat were 237 and 252 mg g⁻¹, respectively, further indicating the excellent adsorption performance of these two POPs. This work provided a smart platform for the construction of POP-based adsorbents to meet the removal demand for pollutants with different charges.