Heptazine-Phloroglucinol Based Hydrophilic Hypercrosslinked Polymers for the Ultrafast Removal of Aromatic Organic Micropollutants

Abstract

The rapid removal of persistent aromatic organic micropollutants (OMPs) from water requires adsorbents with high affinity and excellent dispersibility. To overcome the inherent hydrophobicity and limited functionality of conventional hypercrosslinked polymers (HCPs), we designed a novel C₃-symmetric heptazine monomer (TPH) featuring multiple phenolic hydroxyl groups and an extended π-conjugated system. Two HCP-TPHs, HCP-TPH-1 and HCP-TPH-2, were synthesized directly from this hydrophilic TPH monomer, resulting in materials with high surface area, abundant functional groups, and intrinsic hydrophilicity. These structural characteristics enabled ultrafast adsorption of typical aromatic OMPs. For instance, in the adsorption of rhodamine B by HCP-TPH-1, the pseudo-second-order rate constant reached 61.453 g·mg^–1·min^–1, with a maximum adsorption capacity of 2658 mg·g^–1—both record-high values among all reported adsorbents to date. This study demonstrates a powerful monomer-level design strategy to create advanced HCPs for highly efficient water purification.