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A new nitrogen-rich hierarchical porous polymer (PCPM) was synthesized via a self-catalyzed polycondensation from hexachlorocyclotriphosphazene and melamine under the solvothermal condition, which presented a high adsorption capacity and a fast adsorption kinetics towards three typical water-soluble micropollutants. [Display omitted] • Novel nitrogen-rich hierarchical porous polyphosphazenes were facilely synthesized. • The adsorbent has rich mesopores and a high specific surface area of 321.1 m2/g. • The adsorbent exhibited a high adsorption capacity and a fast adsorption kinetics. • Q max was 187.5, 336.2, and 320.4 mg g−1 for Cr (VI), CR and DCF, respectively. • The adsorption is the result of synergistic action of multiple adsorption mechanisms. The rapid and highly-efficient uptake of waterbody contaminants by polymer-based adsorbent is still a challenge. Herein, a new nitrogen-rich hierarchical porous polymer (PCPM) was synthesized via a self-catalyzed polycondensation between hexachlorocyclotriphosphazene and melamine. The PCPM possessed hierarchical pore architecture with specific surface area of 321.1 m2/g and pore size distribution from 1.3 to 63.0 nm. Owing to the remarkable porous texture and nitrogen-rich active sites with high electron density, PCPM exhibited a high adsorption capacity of 187.5, 336.2, and 320.4 mg g−1 for Cr (VI), Congo red (CR), and diclofenac sodium (DCF), respectively. Moreover, the adsorption rate of these contaminants onto PCPM was very fast, reaching 90 % of adsorption equilibrium capacity for Cr (VI), CR and DCF within the first 7 min, 45 min and 30 min, respectively. Adsorption data revealed that the adsorption process conformed to pseudo-second-order kinetics and Langmuir isotherm model. The removal process was spontaneous, exothermic for Cr (VI) and endothermic for CR and DCF. FT-IR and XPS analysis demonstrated that electrostatic interaction and hydrogen bonding contributed to the adsorption of CR and DCF onto PCPM, while the removal mechanism of Cr (VI) by PCPM included redox reaction and chelation besides the above two interactions. [ABSTRACT FROM AUTHOR]

Porous organic polymers (POPs) have great potential in air and water pollutant treatments. However, the cost-effective syntheis of novel POPs remains a challenge. In this work, we fabricated a new porous organic polymer with P-N linkage (PCPD) via a low-cost catalyst-free polycondensation between 3,3′-diaminobenzidine and hexachlorocyclotriphosphazene under solvothermal conditions. The chemical composition, microstructure and thermal property were characterized by FT-IR, SEM, TEM NMR, DSC, TGA and N 2 sorption. The adsorption performance of PCPD was also studied. The results revealed that PCPD owns good microporosity, N-rich skeleton as well as abundant amino/imine groups. Tested for CO 2 adsorption at 273 K/1 bar and 298 K/1 bar, PCPD exhibited superior CO 2 uptakes of 127.6 mg g−1 and 83.6 mg g−1, respectively. Moreover, the isosteric heats of adsorption at low adsorption values was up to 33.3 kJ mol−1. PCPD also delivered a superior removal performance towards toxic Cr (VI) from aqueous solution with equilibrium adsorption capacity of 205 mg g−1 and instantaneous adsorption capacity of 148 mg g−1 within 5 min at pH= 2. The Cr (VI) adsorption process is spontaneous and exothermic and well obeys intraparticle diffusion model, pseudo-second order kinetics, and Langmuir isotherm model. The plausible removal mechanism included electrostatic interaction, hydrogen bonding interaction, pore filling and the concurrent Cr (VI) reduction followed by in situ chelation on polymer adsorbent. PCPD would open a new field for efficient treatment of air and water pollutants due to its fascinating structure feature and excellent adsorption performance. [Display omitted] • A novel porous organic polymer adsorbent with P-N linkage was designed facilely. • The adsorbent has a specific surface area of up to 366.8 m2 g−1. • High CO 2 capture capacities at atmospheric pressure: 127.6 mg g−1 at 273 K. • Remarkably adsorption capacity towards toxic Cr (VI): 205 mg g−1 at 298 K. • Removal mechanism: electrostatic, H-bond interaction, and reduction-chelation. [ABSTRACT FROM AUTHOR]