Waste wool derived nitrogen-doped hierarchical porous carbon for selective CO2 capture

The goal of this research is to develop a low-cost porous carbon adsorbent for selective CO2 capture. To obtain advanced adsorbents, it is critical to understand the synergetic effect of textural characteristics and surface functionality of the adsorbents for CO2 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 CO2 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 CO2/N2 selectivity, an appropriate CO2 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 CO2 capture.