Carbonaceous materials-supported polyethylenimine with high thermal conductivity: A promising adsorbent for CO2 capture

Abstract

A new three-dimensional (3-D) interconnected elastic scaffold with high thermal conductivity was prepared from hydroxylated graphene (HG) and hydroxylated carbon nanotubes (HCNTs). Then, polyethyleneimine (PEI) was uniformly covalently grafted to the surfaces of the scaffold, to give a HG-HCNTs-PEI nanocomposite as a superior CO2 adsorbent. The resulting nanocomposites possess high amine loading (9.46 mmol N g−1) and high adsorption capacity in simulated flue gas (up to 4.43 mmol CO2 g−1). Due to the excellent thermal conductivity (5.1 W/mK), the adsorbents exhibit superior cyclic stability even in harsh desorption temperature (135 °C), Thus, these carbonaceous materials-supported adsorbents make the CO2 capture process practical and promising.