'Useful' template synthesis of N-doped acicular hollow porous carbon/carbon-nanotubes for enhanced capture and selectivity of CO2

This work reports the synthesis of a N-doped acicular hollow porous carbon/carbon-nanotubes (N-AHPC@H-CNTs) using acicular CaCO3 as a green template and activating agent coupled with FeeCo catalyst, polydopamine and melamine as carbon and nitrogen precursors respectively. The prepared materials were applied for CO2 capture. N-AHPC@H-CNTs were characterized by SEM, TEM, PXRD, XPS, and BET techniques, which revealed their high SSA (S-BET, 561m(2).g(-1)), microporous surface area (351.9m(2).g(-1)), N content (11.60 wt%) having a ratio of Pyrrolic-N (56.63%) and a great mass of ultramicropores (d < 0.7 nm). Attributed to these intriguing characteristics, N-AHPC@H-CNTs exhibited outstanding CO2 capture capacity of 4.43 mmol.g(-1) at 273 K and 3.91 mmol.g(-1) at 298 K at 1.0 bar and good selectivity for CO2/N-2 and CO2/H-2 under the synergistic effect of N-AHPC and CNTs. This flexible and green synthesis approach opens the doors for preparing other similar multifunctional hollow porous carbon/carbon-nanotubes materials for a variety of other applications.