Eco-Friendly Phosphorus and Nitrogen-Rich Inorganic–Organic Hybrid Hypercross-linked Porous Polymers via a Low-Cost Strategy

Low-cost inorganic–organic hybrid hypercross-linked polymers (HCPs) enriched with Lewis base sites (−PN) were constructed by Friedel–Crafts chemistry. Initially, heteroatom-enriched precursors were obtained by nucleophilic substitution of hexachlorocyclotriphosphazene with 2-naphthol, which were then polymerized by Friedel–Crafts alkylation to produce P/N-enriched HCPs. The textural characterization suggested that the obtained polymers (HCP-PN-1 and HCP-PN-2) exhibited high surface areas (420 and 210 m2 g–1) with hierarchical pore size distribution (PSD). The chemical nature and morphology of HCPs were characterized by Fourier transform infrared spectroscopy (FT-IR), 1H NMR spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM) analysis. The heterogeneity of HCPs obtained showed a moderate uptake of CO2 and I2 due to electron-rich phosphazene units and small pores in the range of 1.15–1.2 nm. These findings offer a simple strategy for the synthesis of heteroatom-enriched, high surface area materials in scalable quantity for the development of adsorption materials for industrial use.