Tunable porosity and Hg (II) adsorption performance in dual heteroatom functionalized conjugated micro-mesoporous poly(aniline)s

Conjugated micro-mesoporous poly(aniline)s (CMPAs) synthesized through Buchwald-Hartwig coupling represent a cutting-edge material platform for selective sequestration of Hg (II) but suffer from moderate porosities and constrained availability of adsorption sites. Herein, we show a salt strategy for fine-tuning the porosity and Hg (II) adsorption performance of a series of S, N dual heteroatom functionalized CMPAs (CMPA-SN). The salt of NaF with appropriate dosage results in strikingly improved surface areas from 26 to 735 m 2 /g and intensified Hg (II) adsorption capacity from 311 mg/g to 649 mg/g. Moreover, CMPA-SN exhibits an efficient adsorption rate ( h  = 1250 mg/g/min) and excellent affinity with high K d as high as 1.24 × 10 6 mL/g. We successfully correlate the adsorption capacity and surface area, and reveal the synergistic electron-sharing mechanism from N-containing ligands and in-situ decorated S heteroatoms, with 67.6 %/32.4 % contributions and Δ E ads  = -0.419 eV/Δ E ads  = -0.487 eV adsorption energy.