High-value utilization of lignin to prepare N,O-codoped porous carbon as a high-performance adsorbent for carbon dioxide capture

Abstract

The concern for environmental sustainability has increased the interest in biomass materials for the synthesis of porous carbon, especially as an effective alternative and multifunctional adsorbent in the field of adsorption of a wide range of pollutants and carbon dioxide. Lignin has high carbon content, abundant aromatic rings and condensation bonds, which make it suitable as a precursor for carbon-containing materials. In this study, lignin was firstly precarbonized to achieve its degradation and efficient conversion, and then chemically activated by KOH to prepare a low-cost porous carbon materials with finely developed microporous structure, which showed excellent gas adsorption performance of 3.98 and 5.82 mmol/g at 1 bar, 298 K and 273 K, respectively. In addition to this, we have also investigated the dynamic sorption properties of the samples on CO2. The original lignin contains N,O functional groups that can be doped to the surface of the porous carbon, and previous studies have confirmed that the porosity and functional groups on the surface of the carbon material play a positive role in improving the defective and adsorption properties of the material. Our work provided a promising strategy for valorization of lignin as a precursor for producing advanced carbon materials.