Polyaniline-derived hierarchically porous nitrogen-doped carbons as gas adsorbents for carbon dioxide uptake

Abstract In this work, hierarchically porous nitrogen-doped carbon materials (PNCs) are prepared through a physical activation process by using carbon dioxide as an activating agent and polyaniline as a precursor. The morphology, porous property, and chemical attribute of PNCs are investigated through different technical methods, such as scanning electron microscopy, nitrogen adsorption–desorption measurement, and X-ray photoelectron spectroscopy. The textural property of PNCs can be tuned by varying the activation time. PNCs display high specific surface areas (1030–2900 m 2  g −1 ) and large pore volumes (0.66–1.87 cm 3  g −1 ). When taken as adsorbents for gas capture, PNCs exhibit high carbon dioxide capture capacities (17.2–21.5 wt% at 273 K and 1.0 bar) and good selective adsorption of carbon dioxide over nitrogen or methane. The superior performance can be ascribed to the high porosity, suitable pore size, and the presence of nitrogen functional groups.