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

The goal of this research is to develop a low-cost porous carbon adsorbent for selective CO capture. To obtain advanced adsorbents, it is critical to understand the synergetic effect of textural characteristics and surface functionality of the adsorbents for CO 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 adsorption capacities of 2.78 mmol g and 3.72 mmol g at 25 °C and 0 °C, respectively, under 1 bar. Additionally, this sample also displays a moderate CO/N selectivity, an appropriate CO 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 capture.