Hierarchical porous organic polymers via the in situ construction of the BINOL entity: versatile and efficacious adsorbents for multiple industrial toxic contaminants in water

An efficient synthetic route for the generation of BINOL-based porous organic polymers (POPs) with hierarchical porosity has been developed. As opposed to BINOL-based POPs reported in the literature, which are mostly synthesized from commercial BINOL-based monomers, herein, we generated the BINOL moiety in situ during the polymerization of 2-naphthol-based monomers to achieve our BINOL-based POPs. These BINOL-based POPs showed a high BET surface area of up to 595 m(2) g(-1), good thermal stability up to 328 1C (for BINOL-POP-2), and a hollow tube-like morphology (for BINOL-POP-1). They exhibited the selective adsorption of various cationic and neutral dyes compared with anionic dyes in water with an excellent removal efficiency (499%) and ultrafast kinetics (k = 5.21 min(-1 )for capturing methylene blue). The maximum adsorption capacity (O-max) for these BINOL-based POPs reached 1941 mg g-1 for propidium iodide, 1639 mg g-1 for neutral red and 1390 mg g(-1) for ethidium bromide, which are so far the highest values reported for these dyes. In addition, these POPs could also effectively capture textile dyes, nitroaromatic compounds and toxic bisphenol-A, thus demonstrating these BINOL-based POPs to be versatile adsorbents. Moreover, these POPs are fully recyclable for at least five cycles without losing their adsorption efficiency significantly.

Automated summary

An efficient synthetic route for BINOL-based porous organic polymers (POPs) with hierarchical porosity was developed by generating the BINOL moiety in situ during polymerization. These BINOL-based POPs exhibited high BET surface area, good thermal stability, and selective adsorption of cationic and neutral dyes with excellent removal efficiency and ultrafast kinetics. They also had the highest reported adsorption capacity for various dyes and showed versatility in capturing textile dyes, nitroaromatic compounds, and bisphenol-A. Additionally, these POPs were fully recyclable without significant loss of adsorption efficiency.