Nitrogen-doped microporous carbons as highly efficient adsorbents for CO2 and Hg(II) capture

Nitrogen-doped microporous carbon, which features a uniquely tunable porosity, exhibits promisingly high adsorption prospects in the greenhouse gas capture and water treatment. Herein, we propose a series of novel N-doped microporous carbons (CMPA n -C1000), and precisely tune their porosities via a direct pyrolysis of rigid conjugated microporous poly(aniline)s (CMPA n , n  = 1, 2, 3) with pore size difference in a molecular level, as achieved by simply tuning their linkers with varying sizes, planarity, and symmetry. The CMPA3-C1000, with a satisfactory amount of nitrogen heteroatoms , high S BET of ∼800 m 2  g −1 , and large ultra-micropore volume of 0.25 cm 3  g −1 , has excellent CO 2 capture ability ( i.e. , 5.1 mmol g −1 at 273 K, 1 atm) and Hg(II) adsorption performance ( i.e. , Q e  = 571 mg g −1 ; k 2  = 0.0031 g mg −1  min −1 ), respectively. CMPA3-C1000 might perform chemisorption towards Hg(II), according to calculations using density functional theory and experimental data; nitrogen atoms in porous carbon contributed to this excellent Hg(II) adsorption.