Waste wool derived nitrogen-doped hierarchical porous carbon for selective CO 2 capture.

The goal of this research is to develop a low-cost porous carbon adsorbent for selective CO 2 capture. To obtain advanced adsorbents, it is critical to understand the synergetic effect of textural characteristics and surface functionality of the adsorbents for CO 2 capture performance. Herein, we report a sustainable and scalable bio-inspired fabrication of nitrogen-doped hierarchical porous carbon by employing KOH chemical activation of waste wool. The optimal sample possesses a large surface area and a hierarchical porous structure, and exhibits good CO 2 adsorption capacities of 2.78 mmol g -1 and 3.72 mmol g -1 at 25 °C and 0 °C, respectively, under 1 bar. Additionally, this sample also displays a moderate CO 2 /N 2 selectivity, an appropriate CO 2 isosteric heat of adsorption and a stable cyclic ability. These multiple advantages combined with the low-cost of the raw material demonstrate that this sample is an excellent candidate as an adsorbent for CO 2 capture.