Biomass derived nanoarchitectonics of porous carbon with tunable oxygen functionalities and hierarchical structures and their superior performance in CO₂ adsorption and energy storage

Biomass-derived nanoporous carbons (BNCs) are attractive materials for CO₂ capture and energy storage due to their unique surface properties and the availability of low-cost and abundant supply of carbon sources. However, the order of the carbon atoms, the nature of the porosity and surface functional groups are critical in dictating the performance of BNCs for such applications. Herein, a solid-phase activation strategy is introduced to prepare O-functionalized BNCs with embedded graphene-like structures using D(+)-glucose as a precursor. The optimised material shows a high surface area (3572 m² g⁻¹), and surface oxygenated functional groups, which lead to a high CO₂ adsorption of 5.28 mmol g⁻¹ at 1 bar and 31.5 mmol g⁻¹ at 30 bar at 0 °C. Moreover, as an electrode material, the optimised sample exhibits an impressive specific capacitance (C_s) of 305 F g^-1 at 0.5 A g⁻¹ and 207 F g^-1 at 10 A g⁻¹ in a three-electrode supercapacitor. It also shows high specific capacitance (250 F g^-1 at 0.5 A g⁻¹), a high energy density (58 Wh/kg), and stable cyclic performance in a two-symmetric electrode system. The presented materials and their application performance results are promising and could pave the way for the development of more sophisticated materials for CO₂ capture, energy storage and beyond.